国立感染症研究所

39th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (June 16, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has been declining with approximately 9 per 100,000 population for the latest week of reporting dates. There is a downward trend in regions where the infection has spread. However, there are regions where the decreasing speed has slowed due to an increase in the flow of people, and there is concern about a possible future rebound in these regions.
  • Along with the decrease in the number of new cases of infection, the numbers of severe patients and deaths have decreased.    

    The nationwide effective reproduction number has been declining and remains below 1 at 0.78 (as of May 30).

Analysis of infection status [local trends]

  *The value of new cases of infection is the total number for the latest week of reporting dates per 100,000 population.

  1. (1) Okinawa
    • The number of new cases of infection remains high at approximately 62, but continues to decrease. New cases are mainly in their 20s to 30s and the proportion of minors is also increasing. The use rate of beds remains high, and the hospitalization rate has been increasing as the number of patients receiving home care and those arranging hospitalization are decreasing in association with the decrease in the number of new cases of infection. Schools have been closed due to an increase in the number of infected patients aged 19 years and younger. The nighttime and daytime populations have decreased since the start of the emergency measures. Although the number of new cases of infection may decrease in the future, attention should be paid as to whether these trends will continue.
  2. (2) Hokkaido
    • The number of new cases of infection has continued to decrease to approximately 17. In Sapporo City, the center of infection spread, the number has decreased, but is still at a higher level of approximately 29. The number of new cases of infection is expected to decrease in the future, but the nighttime population, which had continued to decrease, has started to increase. Attention should be paid as to whether the downward trend in the number of new infections will continue. The use rate of beds has remained high in Sapporo City.
  3. (3) Kansai area
    • In Osaka, Hyogo, and Kyoto, the number of new cases of infection has been decreasing to approximately 9, 5, and 8, respectively. As the number of new cases of infection has been decreasing, there has been some improvement such as a decrease in the number of inpatients and severe patients, but clusters in facilities for the elderly are continuing. In Osaka, the nighttime and daytime populations are increasing, but remain at the level of the minimum value during the second declaration of a state of emergency. In Hyogo, the nighttime population remains at a level lower than the minimum value during the second declaration of a state of emergency. In Kyoto, there has been a slight decrease during the latest week. The number of new cases of infection is expected to decrease, but careful monitoring is necessary, also of the de facto population.
  4. (4) Metropolitan area (Tokyo and its 3 neighboring prefectures) 
    • In Tokyo, Saitama, Chiba, and Kanagawa, the number of new cases of infection has been decreasing to approximately 19, 8, 11, and 14, respectively. The ratio of this week to last week has been below approximately 1, but the level remains higher and the decreasing speed slower compared to the Kansai area. Particularly in Chiba and Kanagawa, it is almost flat. In Tokyo, both the nighttime and daytime populations have increased for 5 consecutive weeks. The numbers are returning to the level before the start of the declaration of a state of emergency. In Saitama, the number remains flat, but in Chiba and Kanagawa, both the nighttime and daytime populations have increased from the previous week. There is concern that it is becoming difficult to obtain cooperation with the measures. Particularly in Tokyo, if the upward trend will continue, there is strong concern about rebound and caution is therefore required.
  5. (5) Chukyo area
    • In Aichi, the number of new cases of infection has been decreasing to approximately 12. As the number of new cases of infection has decreased, the number of inpatients and severe patients has decreased, and the use rate of beds both for inpatients and for severe patients is decreasing. The nighttime population has increased slightly but remains at a low level. Although the number of new cases of infection may decrease in the future, attention should be paid as to whether these trends will continue.
    • In Gifu, the number of new cases of infection has been decreasing to approximately 7. The nighttime and daytime populations remain at a low level, and the number of new cases of infection is expected to decrease in the future. In Mie, the number has been decreasing to approximately 5. The nighttime population has been increasing, which leads to concern about possible rebound.
  6. (6) Other areas under emergency measures (Fukuoka, Okayama and Hiroshima)
    • In Fukuoka, the number of new cases of infection has been decreasing to approximately 6. As the number of new cases of infection has decreased, the numbers of inpatients and severe patients have also decreased, and the use rate of beds both for inpatients and for severe patients is decreasing. The nighttime population remains at a low level. The number of new cases of infection is expected to decrease in the future, but it is necessary to carefully watch whether these trends will continue.
    • In Okayama and Hiroshima, the number of new cases of infection has been decreasing to approximately 3 and 7, respectively. As the number of new cases of infection has decreased, the numbers of inpatients and severe patients have also decreased, and the use rate of beds both for inpatients and for severe patients is a on a downward trend. In Okayama, the hospitalization rate exceeds 50%. The nighttime population remains at a low level in both prefectures and the number of new cases of infection is expected to decrease in the future, but attention should be paid as to whether the downward trend in the number of new infections will continue.
  7. (7) Areas other than those listed above
    • In Yamanashi, the number of new cases of infection is approximately 17. The number increased due to the occurrence of clusters and then started to decrease, but it should be watched carefully.

Analysis of mutant strains

  • The proportion of variants of B.1.1.7 lineage (alpha variant) has become approximately 80% of the national total in screening tests, suggesting that the existing strains have almost completely been replaced by mutant strains, except for some regions. In addition, the number of reports of B.1.617.2 lineage variants (including delta variant) is increasing.
  • It has also been reported that the existing strains have being replaced by delta variants overseas, and that this strain may be more infectious and transmissible than alpha variants. It is therefore necessary to continue analysis.

Future outlook and measures to be taken

  • Although a downward trend in the number of new cases of infection may continue nationwide, attention should be paid to the increasing trend in the flow of people, since the existing strains were almost replaced by the variants of B.1.1.7 lineage (alpha variant) and the variants may be more infectious. There are some regions where the flow of people has already started to increase and there is a possibility that the number of new cases of infection may stop decreasing in these regions.
  • In regions under emergency measures and those under priority measures, such as for prevention of the spread of disease (priority measures), the number of infections has decreased owing to the cooperation of citizens and business operators, clearly showing the effect of these measures. In Okinawa and Hokkaido, however, the number of new cases of infection has remained at the level equivalent to the Stage IV. There are some regions where the medical care provision systems remain under severe pressure, although the burden has decreased alongside the decrease in the number of new cases of infection and patients who are receiving care. Therefore, it is necessary reduce the number of new cases of infection as much as possible to prevent a future rebound and to continue to control the increase even if the reduction stops. It is necessary to thoroughly implement the measures based on the "Measures to be taken after June during the declaration of the state of emergency" compiled by the government's Novel Coronavirus Response Headquarters on May 28.
  • Particularly in Tokyo, the flow of people continues to increase. If this trend continues, the number of infected patients will stop decreasing and rebound in future. Vaccinations have been performed mainly in the elderly, and therefore it is expected that severe cases may be suppressed in the elderly. However, if the number of infected patients continues to surge after a rebound, the number of severe patients may increase and the medical care provision systems will be overwhelmed. In addition, there is a burden associated with vaccination at medical institutions. Based on these points, efforts necessary to control the spread of infection should be continued in the future.
  • In other regions and regions where the priority measures are lifted, each local government has to analyze the flow of people, the status of infection and the medical care provision systems in a conference style with experts in the region, and implement the necessary measures in a timely manner, based on the possibility that infection will spread faster than before due to alpha variants and variants of B.1.617 lineage (including delta variants).
  • As for the spread of infection this time, the size, speed, and course of decrease differed among regions. These differences can be attributed to various factors including replacement by variants, contents and timing of the start/end of countermeasures, movement of people or gathering of persons who do not usually meet due to the turn of the start/end of fiscal year or Golden Week holidays, and the age group that became the center of infection, but further investigation is needed.
  • The number of vaccinations has already exceeded 19 million nationwide and approximately 14.5 million people have received the first vaccination. To suppress the spread of infection, it is necessary to promptly and smoothly carry out the vaccination of many people nationwide, including occupational vaccinations.
  • While it is estimated that the existing strains have been replaced by alpha variants as the predominant strain in most regions with some exceptions, it is necessary to take measures focused on an understanding of the actual situation using virus genomic surveillance in order to reinforce the measures against new mutant strains. It is particularly essential concerning mutants, including the delta variants, to suppress the spread of infection as much as possible by following the measures: nationwide monitoring through genomic surveillance and screening of L452R variants, strengthening of systems to conduct tests regionally and active epidemiological surveys. In addition, it is also necessary to continue to take the border control measures promptly.

Figures (Number of new infections reported etc.) (PDF)

38th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (June 9, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has been declining with approximately 13 per 100,000 population for the latest week on the basis of reporting dates. There is generally a downward trend in regions where the infection has spread. However, there are areas where the decreasing speed has slowed due to an increase in the flow of people, and there is a possibility of a rebound in future.
  • Along with the decrease in the number of new cases of infection, the number of severe patients and deaths has started to decrease.

    The nationwide effective reproduction number has been declining and remains below 1 at 0.78 (as of May 16).

Analysis of infection status [local trends]

  *The value of new cases of infection is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates.

  1. (1) Okinawa
    • Two weeks have passed since the start of emergency measures. In Naha City, the southern/middle regions, and the Miyako/Yaeyama areas, the number of new cases of infection continued to surge, mainly among the working generations in their 20s and 30s. The number has decreased since June, but remains above 100 at 103. The use rate of beds has remained at a high level and the hospitalization rate has decreased. Therefore, the number of patients who are receiving care at home has increased. Concern is rising regarding potential increase in the number of severe patients in future and the further burden this may impose on the medical care provision systems. There is concern that transmission of infection in the elderly could cause a further increase of severe patients.
    • The nighttime and daytime populations have decreased since the start of emergency measures. Although the number of new cases of infection may decrease in future, attention should be paid to whether these trends continue. For patients who are receiving care at home or at accommodation facilities, it is necessary to handle issues including preparation for sudden changes in the condition of these patients.
  2. (2) Hokkaido
    • The number of new cases of infection continues to decrease, but the level is above 25 at approximately 29. In Sapporo City, which is the center of infection spread, the number has decreased, but is still at a higher level of approximately 49. In addition, clusters continue to occur at welfare and other facilities. The nighttime population has decreased since the start of emergency measures. Although the number of new cases of infection may decrease in future, attention should be paid to whether these trends continue. The use rate of beds has remained high in Sapporo City. Clusters have also occurred in welfare facilities in other regions than Sapporo.
  3. (3) Kansai area
    • In Osaka, Hyogo, and Kyoto, the number of new cases of infection has been decreasing to approximately 14, 9, and 12, respectively. As the number of new cases of infection has decreased, there is some improvement such as the decrease in the number of inpatients and severe patients, but clusters in facilities for the elderly are continuing. In Osaka, the nighttime and daytime populations are increasing, but remain at a level approximately 10% lower than the minimum value during the second declaration of the state of emergency. In Hyogo, the nighttime population remains at a level lower than the minimum value during the second declaration of the state of emergency. While the number of new cases of infection is expected to continue to decrease, the nighttime population in Kyoto has begun to increase. Therefore, careful monitoring is necessary including the de facto population after improvement in the infection status.
    • In Shiga and Nara, the number of new cases of infection has been on a downward trend to approximately 14 and 8, respectively.
  4. (4) Metropolitan area (Tokyo and its 3 neighboring prefectures) 
    • In Tokyo, Saitama, Chiba, and Kanagawa, the number of new cases of infection has been decreasing to approximately 21, 9, 11, and 16, respectively. The ratio of this week to last week has been below 1 since mid-May, but the level remains higher and the decreasing speed is slower compared to the Kansai area. Particularly in Chiba and Kanagawa, it is almost flat. In addition, there is no apparent downward trend in the number of severe patients.
    • In Tokyo, both the nighttime and daytime populations have increased for 4 consecutive weeks. In particular, the increase from before and after the extension of the declaration of the state of emergency is remarkable. In Saitama, Chiba, and Kanagawa, the trend has remained flat. There is concern that it is becoming difficult to obtain cooperation with the measures. Particularly in Tokyo, if the upward trend continues, there is a possibility of a rebound and caution is therefore required.
  5. (5) Chukyo area
    • In Aichi, the number of new cases of infection has been decreasing to approximately 20. The burden on the healthcare systems continues in spite of the decrease in severe patients, and the use rates of beds are at high levels. The medical care provision systems have been under severe pressure. The number of new cases of infection is expected to decrease in future, but the nighttime and daytime populations have slightly increased. Attention should be paid to whether the downward trend in the number of new infections continues.
    • In Gifu, the number of new cases of infection has been decreasing to approximately 15. The nighttime and daytime populations remain at a low level, and the number of new cases of infection is expected to decrease in future. In Mie, the number has been decreasing to approximately 8. The nighttime population has been increasing, which leads to concern about a rebound. In Shizuoka, the number has also been decreasing to approximately 7.
  6. (6) Kyushu
    • In Fukuoka, the number of new cases of infection has been decreasing to approximately 11. Although the number of inpatients and severe patients has decreased, there is a great burden on the medical care provision systems. The nighttime population remains low. The number of new cases of infection is expected to decrease in future, but it is necessary to carefully watch whether these trends continue.
    • In Kumamoto, the number of new cases of infection has continued to decrease to approximately 5. As the number of new cases of infection has decreased, the use rate of both beds for inpatients and beds for severe patients is decreasing, which secures the hospitalization rate above 50%. In other Kyushu prefectures, the decreasing trend generally continues.
  7. (7) Other areas under emergency measures (Okayama and Hiroshima) and those under priority measures, such as for prevention of the spread of disease (Gunma and Ishikawa)
    • In Okayama and Hiroshima, the number of new cases of infection has been decreasing to approximately 7 and 12, respectively. In both prefectures, the number of severe patients has decreased, while the use rate of beds remains high. The nighttime population remains at a low level in both prefectures and the number of new cases of infection is expected to decrease in future, but attention should be paid to whether the downward trend in the number of new infections continues.
    • In Gunma and Ishikawa, the number of new cases of infection has been decreasing to approximately 5 and 7, respectively. As the number of new cases of infection has decreased in both prefectures, the use rate of both beds for inpatients and beds for severe patients is decreasing, which secures the hospitalization rate above 50%.
  8. (8) Areas other than those listed above
    • In Yamanashi and Kochi, the number of new cases of infection exceeds 15 at 21 and 18, respectively. While the number has started to decrease in Kochi, it has increased in Yamanashi due to the occurrence of clusters and should be watched carefully.

Future outlook and measures to be taken

  • Although a downward trend in the number of new cases of infection may continue nationwide, attention should be paid to the increasing trend in the flow of people, since the existing strains were almost replaced by the variants of B.1.1.7 lineage (alpha variant) and the variants may be more infectious. There are some regions where the flow of people has already started to increase and there is a possibility that the number of new cases of infection may stop decreasing in these regions.
  • In regions under emergency measures and those under priority measures, such as for prevention of the spread of disease (priority measures), the number of infections has decreased owing to the cooperation of citizens and business operators, clearly showing the effect of these measures. In Okinawa and Hokkaido, however, the number of new cases of infection has remained at the level equivalent to the Stage IV. There are some regions where the medical care provision systems remain under severe pressure, although the burden has decreased alongside the decrease in the number of new cases of infection and patients who are receiving care. Therefore, it is necessary reduce the number of new cases of infection as much as possible to prevent a future rebound and to continue to control the increase even if the reduction stops. It is necessary to thoroughly implement the measures based on the "Measures to be taken after June during the declaration of the state of emergency" compiled by the government's Novel Coronavirus Response Headquarters on May 28.
  • Particularly in Tokyo, the flow of people continues to increase. If this trend continues, the number of infected patients will stop decreasing and rebound in future. Vaccinations have been performed mainly in the elderly, and therefore it is expected that severe cases may be suppressed in the elderly. However, if the number of infected patients continues to surge after a rebound, the number of severe patients may increase and the medical care provision systems will be overwhelmed. In addition, there is a burden associated with vaccination at medical institutions. Based on these points, efforts necessary to control the spread of infection should be continued in the future.
  • In other regions and regions where the priority measures are lifted, each local government has to analyze the flow of people, the status of infection and the medical care provision systems in a conference style with experts in the region, and implement the necessary measures in a timely manner, based on the possibility that infection will spread faster than before due to alpha variants and variants of B.1.617 lineage (including delta variants).
  • As for the spread of infection this time, the size, speed, and course of decrease differed among regions. These differences can be attributed to various factors including replacement by variants, contents and timing of the start/end of countermeasures, movement of people or gathering of persons who do not usually meet due to the turn of the start/end of fiscal year or Golden Week holidays, and the age group that became the center of infection, but further investigation is needed.
  • The number of vaccinations has already exceeded 19 million nationwide and approximately 14.5 million people have received the first vaccination. To suppress the spread of infection, it is necessary to promptly and smoothly carry out the vaccination of many people nationwide, including occupational vaccinations.
  • While it is estimated that the existing strains have been replaced by alpha variants as the predominant strain in most regions with some exceptions, it is necessary to take measures focused on an understanding of the actual situation using virus genomic surveillance in order to reinforce the measures against new mutant strains. It is particularly essential concerning mutants, including the delta variants, to suppress the spread of infection as much as possible by following the measures: nationwide monitoring through genomic surveillance and screening of L452R variants, strengthening of systems to conduct tests regionally and active epidemiological surveys. In addition, it is also necessary to continue to take the border control measures promptly.

Figures (Number of new infections reported etc.) (PDF)

37th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (June 6, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has been declining since mid-May and results in approximately 18 per 100,000 population for the latest week on the basis of reporting dates. The number on the basis of onset dates also tends to decrease since early May. There is generally a downward trend in regions where the infection has spread. In some regions, however, the number remains flat or increases. Under such circumstances, flow of people has recently increased in various regions and there is a possibility of a rebound in the future. Along with the decline in the number of new cases of infection, the number of severe patients, which had been increasing, has recently declined, while the number of deaths has remained high.  

    The nationwide effective reproduction number has been declining and remains below 1 at 0.82 (as of May 16).  

Analysis of infection status [local trends]

  *The value of new cases of infection is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates. The effective reproduction number represents the mean value of the most recent week (as of May 17)

  1. (1) Okinawa
    • In Okinawa, 1 week has passed since the start of emergency measures. In Naha City, the southern/middle regions, and the Miyako/Yaeyama areas, the number of new cases of infection continues to surge, mainly among the working generations in their 20s and 30s, and the number has remained at an unprecedentedly high level of approximately 126. The use rate of beds has remained at a high level, the hospitalization rate has decreased, and the number of patients who are receiving care at home and cases in the process of arranging hospitalization has increased. The number of severe patients has increased and a further burden may be imposed on the medical care provision systems. Although the number of patients in their 70s has flattened for the latest week, there is particular concern that transmission of infection among elderly people could cause a further increase in severe patients.
    • The nighttime and daytime populations have decreased since the start of emergency measures; however, the ratio of this week to last week has remained above 1 and the number of infected patients may increase for the time being. As the number of patients who are receiving care at home or at accommodation facilities is increasing, it is necessary to handle issues including the preparation for sudden changes in the condition of these patients.
  2. (2) Hokkaido
    • Two weeks have passed since the start of emergency measures. The number of new cases of infection has decreased since late May, but is very high at approximately 53. The number of severe patients has not decreased. In Sapporo City, which is the center of infection spread, the number has decreased, but is still at a higher level of approximately 92. In addition, clusters continue to occur at hospitals and welfare facilities. The nighttime and daytime populations have decreased since the start of emergency measures and have remained at a low level. Although the number of new cases of infection may decrease in the future, attention should be paid to whether these trends continue. The medical care provision systems in Sapporo have been under severe pressure and the use rate of beds remains at a high level. There have also been cases of wide-area medical evacuations transported outside the city. Clusters have also occurred in welfare facilities in other regions than Sapporo. Actions to prevent expansion are required.
  3. (3) Kansai area
    • In Osaka, Hyogo, and Kyoto, 5 weeks have passed since the start of emergency measures. The number of new cases of infection has decreased to approximately 19, 13, and 13, respectively.
    • In Osaka, the nighttime and daytime populations are increasing, but remain at a level approximately 20% lower than the minimum value during the second declaration of the state of emergency. In Hyogo and Kyoto, the nighttime population remains at a level lower than the minimum value during the second declaration of the state of emergency. The effective reproduction number in Osaka, Hyogo, and Kyoto is below 1, respectively. While the number of new cases of infection is expected to continue to decrease, careful monitoring is necessary including the de facto population after improvement in the infection status.
    • The situation has improved according to the decrease in the number of new cases of infection. However, the healthcare provision systems remain under severe pressure, mainly in Osaka and Hyogo, as the number of severe patients is decreasing in Osaka but remains at a high level in Hyogo. Clusters continue to occur in places such as elderly facilities.
    • In Shiga, the number of new cases of infection has increased again, reaching approximately 20. In Nara and Wakayama, the number of new cases of infection has been on a downward trend to approximately 11 and 5, respectively.
  4. (4) Metropolitan area (Tokyo and its 3 neighboring prefectures) 
    • In Tokyo, 5 weeks have passed since the start of emergency measures. In Saitama, Chiba and Kanagawa, 6 weeks have passed since the start of priority measures. The number of new cases of infection has been decreasing since mid-May, to approximately 27, 12, 11 and 16, respectively. The ratio of this week to last week has been below 1 since mid-May, but the level remains higher and the decreasing speed is slower compared to the Kansai area. There was also no apparent decreasing trend in severe patients in Tokyo and Kanagawa.
    • In Tokyo, both the nighttime and daytime populations have clearly increased. In Saitama, Chiba, and Kanagawa, the trend has been from flat to slightly increasing. The nighttime population in Tokyo is gradually reaching the level in March. There is concern that it is becoming difficult to obtain cooperation with the measures. If the upward trend continues, there is a possibility of rebound, and caution is therefore required.
  5. (5) Chukyo area
    • In Aichi, 3 weeks have passed since the start of emergency measures. Although the number of new cases of infection started to decrease in late May, it remains at a high level of approximately 31. The burden on the healthcare systems has continuously increased due to an increase in severe patients, and the use rates of beds are at high levels. The medical care provision systems have been under severe pressure. The nighttime population has fluctuated around the lowest level during the second declaration of the state of emergency. The daytime population has increased slightly. The number of new cases of infection is expected to decrease in the future, but it is necessary to carefully monitor whether these trends will continue.
    • In Gifu and Mie, 3 weeks have passed since the start of priority measures. In Gifu, the number of new cases of infection has been decreasing to approximately 22. The nighttime population remains at a low level, and the number of new cases of infection is expected to decrease in the future. In Mie, the number has been decreasing since late May, to approximately 11. The nighttime population has clearly been increasing, which leads to concern about rebound. In Shizuoka, the number has also been decreasing to approximately 11.
  6. (6) Kyushu
    • In Fukuoka, 3 weeks have passed since the start of emergency measures. The number of new cases of infection continues to decrease to approximately 21. As the number of new cases of infection has decreased followed by a drop in the number of inpatients, the number of severe patients may peak out. The use rate of beds, however, remains high and there continues to be a heavy burden on the medical care provision systems. The nighttime population has not reached the lowest level during the second declaration of the state of emergency, but remains at a low level. The number of new cases of infection is expected to decrease in the future, but it is necessary to carefully watch whether these trends continue.
    • In Kumamoto, 2 weeks have passed since the start of priority measures. The number of new cases of infection has continued to decrease to approximately 14. In other prefectures in Kyushu, the number of new cases of infection is on a downward trend. The ratio of this week to last week has been decreasing below 1 and the number of new cases of infection may continue to decrease. However, it needs to be monitored continuously.
  7. (7) Other areas under emergency measures (Okayama and Hiroshima) and those under priority measures (Gunma and Ishikawa)
    • In Okayama and Hiroshima, 2 weeks have passed since the start of emergency measures. Although the number of new cases of infection has continued to decrease to approximately 18 and 26, respectively, the number in Hiroshima remains above 25. In Hiroshima, the number of severe patients is on an upward trend and the use rate of beds is at a high level in both Okayama and Hiroshima. In both prefectures, the nighttime and daytime populations have decreased since the start of emergency measures, and the number of new cases of infection may continue to decrease in the future. However, in Okayama, the nighttime population starts to increase following the decrease in the number of infected patients. Therefore, it is necessary to carefully watch whether the downward trend in the number of new cases of infection will continue.
    • In Gunma and Ishikawa, 2 weeks have passed since the start of priority measures. In both prefectures, the number of new cases of infection has been decreasing to approximately 10 and 15, respectively. The nighttime population is on a decreasing trend and is expected to decrease in the future, but it is necessary to watch carefully whether this trend continues.
  8. (8) Areas other than those listed above
    • In Kochi, the number of new cases of infection is approximately 26. The number stays at a high level exceeding 25 and attention is also required hereafter.

Analysis of mutant strains

  • The proportion of variants of B.1.1.7 lineage (alpha variant) has become approximately 80% of the national total in screening tests, suggesting that the existing strains have almost completely been replaced by mutant strains, except for some regions. In addition, the number of reports of variants of B.1.617 lineage (including delta variants) is increasing.
  • It is also necessary to establish a medical care system and provide treatment assuming the possibility of an increased risk of the disease becoming more severe due to alpha variants.
  • It has also been reported that the existing strains have being replaced by delta variants overseas, and that this strain may be more infectious and transmissible than alpha variants. Therefore, it is necessary to continue analyses.

Measures to be taken

  • Although the decreasing trend may continue nationwide except in some regions, attention should be paid to the increasing trend in the flow of people. The increase is expected to continue in Okinawa. The existing strains have almost been replaced by alpha variants nationwide, and the expansion speed of the variants is faster than before. It tends to take longer than before for the decrease in the flow of people to lead to a reduction in the number of new cases of infection. In addition, even in regions where the number of new cases of infection is decreasing, the number of severe patients continues to increase or remains high. Therefore, the number of infected patients needs to be reduced continuously.
  • On the other hand, in other regions under emergency measures than Okinawa and those under priority measures, the number of infections has decreased owing to the cooperation of citizens and business operators, clearly showing the effect of these measures. However, the number of new cases of infection has remained at a level equivalent to Stage IV in several regions, and the medical care provision systems continues to be under severe pressure in many regions. There are also some regions where the flow of people has already started to increase, and there is a possibility that the number of new cases of infection may stop decreasing. It is required to reduce the number of new cases of infection as far as possible to prevent future rebound, and to continue to control the increase even if the reduction stops. For this reason, it is necessary to thoroughly implement the measures based on the "Measures to be taken after June during the declaration of the state of emergency" compiled by the government's Novel Coronavirus Response Headquarters on May 28.
  • The number of vaccinations has already exceeded 13 million nationwide, and approximately 9.8 million people have received the first vaccination. To suppress the spread of infection, it is necessary to promptly and smoothly carry out vaccination of many people nationwide, including occupational vaccination. • Based on the results of past efforts, the current infection status, the status of medical care provision systems, and the possibility that infection will spread faster than before due to alpha and delta variants, each local government has to analyze the flow of people, the status of infection and the medical care provision systems in a conference style with experts in the region, and implement the necessary measures in a timely manner.
  • While it is estimated that the existing strains have been replaced by alpha variants as the predominant strain in most regions with some exceptions, it is necessary to take measures focused on an understanding of the actual situation using virus genomic surveillance in order to reinforce the measures against new mutant strains. Particularly concerning mutants including the delta variants, it is essential to suppress the spread of infection as far as possible by following the measures: nationwide monitoring through genomic surveillance, strengthening of systems to conduct tests regionally and active epidemiological surveys. In addition, while the border control measures have been strengthened several times, it is continuously required to deal with issues promptly.

Figures (Number of new infections reported etc.) (PDF)

36th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (May 26, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has decreased since mid-May on the basis of reporting dates, and the number in the most recent week is approximately 26 per 100,000 population. There may be a decreasing trend in the epi-curve on the basis of onset dates. While a levelling-off trend or a decreasing trend has been shown in some regions, other regions still face an increasing trend. The situation continues to require caution. The trend in the number of severe patients or deaths shifted from increasing to flat, but the latest level has remained high.
  • In particular, in the metropolitan areas such as the Tokyo, Kansai, and Aichi areas, the flow of people decreased by various measures, but as the predominant strains are being replaced by mutants first detected in the UK (B.1.1.7), it has taken longer than before until the number of new cases of infection decreases. Under such circumstances, the flow of people has recently increased in various regions. Attention should be paid to the situation including changes in the number of new cases of infection.

    The nationwide effective reproduction number stayed at around 1 and has recently become 0.95 (as of May 9), marking the drop below 1.

Analysis of infection status [local trends]

 *The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates. The effective reproduction number represents the mean value of the most recent week (as of May 10)

  1. (1) Kansai area
    • In Osaka, Hyogo, and Kyoto, 4 weeks have passed since the start of emergency measures. The number of new cases of infection is approximately 30, 22, and 24, respectively. In Osaka and Hyogo, the number of new cases of infection continues to decrease, and a decreasing trend has been also shown in Kyoto. The number in Osaka, however, is still at a high level above 25.
    • In Osaka, the nighttime and daytime populations keep at a level approximately 30% lower than the minimum value during the second declaration of the state of emergency. In Hyogo and Kyoto, the nighttime population remains at a level lower than the minimum value during the second declaration of the state of emergency. The effective reproduction number is 0.69, 0.64, and 0.85 in Osaka, Hyogo, and Kyoto, respectively. While the number of new cases of infection is expected to continue to decrease, careful monitoring is necessary including the de facto population after the improvement of the infection status.
    • Mainly in Osaka and Hyogo, the medical care provision systems and public health systems are under very severe pressure. In Osaka, the number of patients receiving care at accommodation facilities, the number of inpatients and the use rate of beds for severe patients are decreasing as is the number of patients receiving care at accommodation facilities in Hyogo, but the other numbers remain at the same level. Although the situation is expected to improve alongside the decrease in the number of new cases of infection, general medical care still remains restricted. Clusters in places such as elderly facilities continue to occur.
    • In Shiga, Nara, and Wakayama, the number of new cases of infection is on a downward trend to approximately 19, 18, and 8, respectively.
  2. (2) Metropolitan area (Tokyo and its 3 neighboring prefectures) 
    • In Tokyo, 4 weeks have passed since the start of emergency measures. In Saitama, Chiba and Kanagawa, 5 weeks have passed since the start of priority measures. The number of new cases of infection has been flat or declining since mid-May, to approximately 31, 16, 13 and 20, respectively. Many people are in their 20s to 50s. The ratio of this week to last week is recently below 1. On the other hand, there may be effects by fluctuations in the number of infected patients during the Golden Week holidays (GW). Considering this point, we cannot be over-optimistic about the future.
    • In Tokyo, the nighttime and daytime populations have been increasing to the lowest level during the second declaration of the state of emergency. In Saitama, Chiba, and Kanagawa, the trend has remained flat. If the flow of people continues to be on an upward trend in Tokyo, there is a possibility of a rebound, and therefore, caution is required.
  3. (3) Chukyo area
    • In Aichi, 2 weeks has passed since the start of emergency measures. The number of new cases of infection increased rapidly, but has been flat since mid-May, at a high level of approximately 48. Many people are in their 20s to 30s. The burden on medical institutions and public health centers has continuously increased, and the use rates of beds are at high levels. The medical care provision systems have been under severe pressure.
    • The nighttime population has slightly decreased and has fluctuated around the lowest level during the second declaration of the state of emergency. The daytime population has decreased since the declaration of the state of emergency. Five weeks or more have passed since the de facto population decreased, and it is necessary to carefully watch whether the number of new cases of infection decreases.
    • In Gifu and Mie, 2 weeks have passed since the start of priority measures. In Gifu, the number of new cases of infection has decreased since mid-May, to approximately 30. As the nighttime and daytime populations are decreasing, it is expected to decrease in the number of new cases of infection. In Mie, the number of new cases of infection has also decreased to approximately 12. In Shizuoka, the number of new cases of infection continued to increase, but has decreased after mid-May, to approximately 13. Attention should be paid to future trends.
  4. (4) Kyushu/Okinawa
    • In Okinawa, 6 weeks have passed since the start of priority measures. Emergency measures have been applied since May 23. In the metropolitan areas including Naha City and the Yaeyama area, the number of new cases of infection has surged mainly in the working generations in their 20s and 30s, and the number has remained at a high level of approximately 93. There have been infections in persons coming from outside the prefecture. The use rate of beds has increased and further burden may be imposed on the medical care provision systems due to increase in the number of infected patients. Although the percentage of patients in their 60s is low at present, there is particular concern that transmission of infection in the elderly could cause an increase of severe patients.
    • The nighttime population, which decreased after the priority measures, has increased during GW. As there was only a slight decrease after GW, the number of infected patients is expected to continue to increase in the future.
    • In Fukuoka, 2 week has passed since the start of emergency measures. The number of new cases of infection continued to surge mainly among people in their 20s to 30s, but has decreased since mid-May, to approximately 44. The ratio of this week to last week has recently been 1 or less. However, the number of infected patients remains at a very high level. The use rate of beds is also increasing, and there continues to be a heavy burden on the medical care provision systems.
    • The effective reproduction number is 1 or less, and it is expected that the number of new cases of infection will decrease. However, after emergency measures, there was only a slight decrease in the nighttime population, which has not decreased to the minimum level at the time of the second declaration of the state of emergency. Therefore, it is necessary to watch carefully.
    • In Kumamoto, 1 week has passed since the start of priority measures. The number of new cases of infection has decreased since mid-May, to approximately 26.
    • There is a downward trend in other prefectures in the Kyushu area, but the number of infected patients in Saga and Oita exceeds 15, reaching approximately 20 and 24, respectively. The ratio of this week to last week has been decreasing below 1 and may continue to decrease. However, it needs to be monitored continuously.
  5. (5) Hokkaido
    • In Hokkaido, 2 weeks and 1 week have passed since the start of priority measures and emergency measures, respectively. The number of new cases of infection is increasing to a high level of approximately 78. The number in Sapporo City is at a higher level of approximately 127. In addition, clusters have occurred at hospitals and welfare facilities. The nighttime and daytime populations have decreased since emergency measures. However, the ratio of this week to last week remains above 1, though there is a decreasing trend, and the increase may continue in future. The medical care provision systems in Sapporo have been under severe pressure and the use rate of beds remains at a high level. In addition, there have been cases of wide-area medical evacuations transported outside the city.
  6. (6) Other areas under emergency measures (Okayama and Hiroshima)
    • In Okayama and Hiroshima, 1 week has passed since the start of emergency measures. The number of new cases of infection has decreased in Okayama since mid-May and has started to decrease in Hiroshima as well, but it is still at a high level of approximately 35 and 43, respectively. The use rate of beds is at a high level in both prefectures. In both prefectures, the nighttime and daytime populations are continuously decreasing and the ratio of this week to last week has recently been 1 or less. It is necessary to carefully monitor whether the decreasing trend continues.
  7. (7) Other areas under priority measures, such as for prevention of the spread of disease (Gunma and Ishikawa)
    • In Gunma and Ishikawa, 1 week has passed since the start of priority measures. In both prefectures, the number of new cases of infection has been decreasing since mid-May, to approximately 17 and 27, respectively (in Ishikawa, the number has currently increased in clusters in school settings). The effective reproduction number was below 1 in both prefectures and the ratio of this week to last week has been below 1. The number is expected to decrease in the future, but attention should be paid to whether the trend continues.
  8. (8) Areas other than those listed above
    • The number of new cases of infection in Aomori, Toyama, Yamaguchi and Kochi exceeds 15, reaching approximately 16, 22, 21 and 20, respectively. There is a downward trend in Yamaguchi, and a levelling-off trend in Aomori, while an upward trend continues in Toyama and Kochi. It is necessary to pay close attention in future.

Analysis of mutant strains

  • The proportion of B.1.1.7 variants has become approximately 80% of the national total in screening tests, suggesting that the existing strains were almost all replaced by the mutant strains, except for some regions. As for B.1.617 (the mutant strain first detected in India) in Japan, there are cases where infection has been confirmed from people who have not traveled abroad.
  • It is necessary to establish medical care systems and provide treatments assuming the possibility of increased risk of disease becoming severer due to B.1.1.7.
  • In addition, it has been reported that B.1.617 is being replaced with the existing ones overseas, and it has been also suggested that this strain may be more infectious and transmissible than B.1.1.7. Therefore, it is necessary to continue analyses.

Measures to be taken

  • Although the downward trends may continue in the Tokyo metropolitan and Kansai areas, attention should be paid as there are fluctuations in the flow of people. In Aichi, it is necessary to keep a close watch on whether the number of infected patients will clearly decrease. The increase is expected to continue in Okinawa. The B.1.1.7 variants have almost replaced the existing ones nationwide. The variants are expected to be faster in expansion and it may take longer to curb the spread of the variants. In addition, the number of severe patients is increasing or remains at a high level in many regions, and therefore the increase of infected patients should be continuously reduced.
  • It takes longer than before until a decrease in the flow of people leads to a reduction in the number of new cases of infection. On the other hand, in some regions under emergency measures and those under priority measures, the number of infections has decreased or stopped increasing owing to cooperation of citizens and business operators, which indicates the effect of these measures. However, in regions where the number of infected patients continues to increase or has not decreased, the effect of these measures is still limited due to the influence of GW. In many regions, the number of new cases of infection has reached the level equivalent to the Stage IV, and the medical care provision systems continues to be under severe pressure. Therefore, continuation of necessary measures is required.
  • Based on the results of past efforts, the current infection status, the status of medical care provision systems, and the possibility that infection spread will progress faster than before due to B.1.1.7 and B.1.167, each local government needs to analyze the status of infection and the medical care provision systems at a conference body with experts in the regions and implement necessary measures in a timely manner.
  • It is essential to analyze and evaluate the timing of the priority measures and the emergency measures, their contents, and their effects during the expansion of the current epidemic, and to utilize the results for future operations. In addition, in each region, testing strategies utilizing the antigen qualitative tests and strengthening of the medical care provision systems should be carried forward based on the materials of the 33th ADB meeting and the discussions in the 5th Advisory Committee on the Basic Action Policy.
  • The effectiveness of vaccines has been reported. It is expected that vaccinations in wider populations can reduce severe cases and then inhibit infection of the virus. Vaccination in the large-scale vaccination centers has been initiated, and it is necessary for the national and local governments to work together to offer vaccinations for many people as quickly and efficiently as possible.
  • In some regions, the effects of masks are being analyzed. Taking into account these results, it is important to thoroughly wear a mask when conversing with others, including mealtimes. With the efforts in each region, it is indispensable to continue to communicate the importance of taking basic measures for infection control, such as proper wearing of masks, at various occasions in daily life, including workplaces and school settings. On the other hand, it is necessary ensure people understand that wearing a mask does not give complete immunity, and it should be also noted that compliance is difficult to ensure.
  • While it is estimated that the existing strains have been replaced with B.1.1.7 as the predominant strains in most regions with some exceptions, it is necessary to take measures focusing on understanding the actual situation using virus genomic surveillance in order to reinforce the measures against new mutant strains. Particularly for B.1.617, which has been positioned as VOC, it is essential to suppress the spread of infection in Japan as much as possible by following measures: nationwide monitoring through genomic surveillance, and active epidemiological surveys. In addition, while the border control measures have been strengthened, past measures need to be verified. Prompt actions will be required based on the occurrence status outside Japan and at quarantine stations in Japan, as well as the effects of the previous measures.

Figures (Number of new infections reported etc.) (PDF)

35th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (May 19, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has stopped increasing based on the reporting date, and the number in the most recent week is approximately 32 per 100,000 population. As in the previous week, the figure does not indicate nationwide spread of infection, and the trends are different between regions; some are in an increasing trend, some remains the same, and some are in a decreasing trend. The numbers of severe patients and deaths are continuing to increase.
  • The number of infections has not clearly decreased at present. The effects of the movement of people during GW and the effects of mutant strains are intricately intertwined with the effects of various measures to control the infection, and it is difficult to evaluate the statuses and estimate the future. Attention should be paid to future movements.

    The nationwide effective reproduction number remains stable around 1, most recently 1.01 (as of May 2).

Analysis of infection status [local trends]

 *The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates. The effective reproduction number represents the mean value of the most recent week (as of May 3)

  1. (1) Kansai area
    • In Osaka, 6 weeks have passed since the start of priority measures, such as for prevention of the spread of disease (hereinafter referred to as “priority measures”), and 3 weeks since the start of emergency measures. The ratio of this week to last week has been 1 or lower for the most recent 2 weeks and the number of new cases of infection is decreasing, but remains extremely high. The nighttime and daytime populations rapidly decreased to the previous lowest level, and then increased. It took approximately 5 weeks from the decrease in the de facto population to the resulting decrease in the number of new cases of infection. The effective reproduction number is 0.87, 0.99, and 0.98 in Osaka, Hyogo, and Kyoto, respectively. While the number of new cases of infection is expected to continue to decrease, careful monitoring is necessary including the de facto population.
    • The number of new cases of infection is about 51, 36, 37 and 34 in Osaka, Hyogo, Kyoto and Nara, respectively. A decreasing trend has been generally observed, except for Kyoto whose figure is almost flat, but the number of new cases of infection is high in all age groups.
    • Mainly in Osaka and Hyogo, the medical care provision systems and public health systems are under very severe pressure. General medical care has been inevitably restricted. Efforts have been made to secure beds. It is essential to keep a downward trend in the number of new cases of infection to protect the system for necessary and timely care.
    • In Wakayama, the number of new cases of infection is in a decreasing trend, about 12. The figure remains almost stable, about 23, in Shiga.
  2. (2) Metropolitan area (Tokyo and its 3 neighboring prefectures)  
    • In Tokyo, 5 weeks and 3 weeks have passed since the start of priority measures and emergency measures, respectively. In Saitama, Chiba and Kanagawa, 4 weeks have passed since the start of priority measures. The number of new cases of infection remains almost stable in Tokyo (though the status is difficult to assess), and it remains stable or slightly increased in Saitama, Chiba and Kanagawa; the figure is about 38, 22, 16 and 22, respectively in these prefectures. Many people are in their 20s to 50s. The ratio of this week to last week increased after GW and is generally in a decreasing trend most recently.
    • In Tokyo, the nighttime and daytime populations reached a level 25% lower than the lowest value during the second Declaration, showed an increasing trend after GW, and then has become the same level of the lowest during the second Declaration. Three weeks have passed since the decrease in nighttime population was observed, but the number of new cases of infection has not been past the peak. The nighttime population remains stable or is increasing after GW also in Saitama, Chiba and Kanagawa, and the daytime population increased in Chiba and Saitama. The effective reproduction number is 1.03, 1.57, 1.08 and 1.14, respectively, and the number of cases of infection may increase or decrease. It is necessary to carefully follow movements in the de facto population and the number of new cases of infection.
  3. (3) Chukyo area
    • In Aichi, 4 weeks and 1 week have passed since the start of priority measures and emergency measures, respectively. The trend of rapid increase in the number of new cases of infection is continuing and the figure has reached about 52. The ratio of this week to last week has remained 1 or higher over about 8 weeks since late March. The cases of infection are mainly of those in their 20s to 30s, but the number of new cases of infection tends to increase in almost all generations. The burden on medical institutions and public health centers is increasing, the use rates of beds are at high levels, and the medical care provision systems are under severe pressure.
    • The nighttime population remains stable after issuance of the Declaration of State of Emergency, and has fluctuated around the lowest level during the second Declaration of Emergency State. In contrast, the daytime population started to increase from the latter half of GW and slightly decreased after issuance of the Declaration of State of Emergency. More than 4 weeks have passed since a decrease in the de facto population was observed, but the effective reproduction number has been 1 or higher, and the number of new cases of infection may continue to increase.
    • One week has passed since the start of priority measures in Gifu and Mie. The trend of increase in the number of new cases of infection is continuing in Gifu with the figure reaching about 44. Although the nighttime and daytime populations are decreasing, it is necessary to watch carefully whether the number of new cases of infection will decrease. The figure remains stable, about 18, in Mie. The ratio of this week to last week has rapidly increased since mid-May in Shizuoka and has been 1 or higher for about 3 weeks. The number of new cases of infection is about 17, and should receive close attention.
  4. (4) Kyushu/Okinawa
    • One week has passed since the start of emergency measures in Fukuoka. The number of new cases of infection has rapidly increased mainly in persons in their 20s and 30s since mid-April. The rate of increase slightly slowed down most recently, but the number is still very high, about 64. The ratio of this week to last week has remained 1 or higher over 6 weeks since early April. The bed occupancy rate is rapidly increasing and the burden on the medical care provision systems is still large.
    • The nighttime population was decreasing but did not reach the lowest level during the second Declaration of State of Emergency; it has remained stable after issuance of the Declaration of State of Emergency, and the daytime population increased before issuance of the Declaration of State of Emergency but slightly decreased afterwards. The effective reproduction number has remained 1 or higher, and the number of new cases of infection may continue to increase.
    • Priority measures have been taken since May 16 in Kumamoto. The number of new cases of infection had rapidly increased; the rate of increase slowed down most recently, but the figure is high, about 39.
    • A turn to decline has been observed in other prefectures in the Kyushu area, but the figures are still high, about 29 and 38 in Saga and Oita, respectively. The effective reproduction number is 1.35 in both prefectures; the ratio of this week to last week is in a decreasing trend which may continue and should be carefully monitored.
    • In Okinawa, 5 weeks have passed since the start of priority measures. Despite the priority measures, the number of new cases of infection has increased since GW, mainly in the working generations, 20s and 30s, in the metropolitan areas including Naha City and the Yaeyama area, with figures as high as about 57. There have been infections in persons coming from outside the prefecture. Medical care is expected to be in an impending situation if the number of cases of infection increases. There is particular concern that transmission of infection in the elderly could cause an increase of severe patients.
  5. (5) Other areas under emergency measures (Hokkaido, Okayama and Hiroshima)
    • In Hokkaido, priority measures and emergency measures were applied on May 9 and May 16, respectively. Rapid increase in the number of new cases of infection is continuing; the figure is very high, about 72. The ratio of this week to last week has been 1 or higher for about 6 weeks. The figure is at a high level, about 125, in Sapporo City, and many cases with an unknown link have occurred in the community. Clusters also occurred at hospitals and welfare facilities. The effective reproduction number is high, 1.57, and may continue to increase. The medical care provision systems in Sapporo have been under severe pressure, the use rate of beds is at a high level, and there have been cases of wide-area medical evacuations transported outside the city.
    • Emergency measures were applied to Okayama and Hiroshima on May 16. The figures are high, about 59 and 53, respectively. The ratio of this week to last week has been 1 or higher for 7 weeks in Okayama, and 5 weeks in Hiroshima. The use rate of beds is at a high level in both prefectures. In Okayama, the nighttime and daytime populations are decreasing. The effective reproduction numbers are high, i.e., 1.30 and 1.76, respectively. The infection may further spread from now on.
  6. (6) Other areas under priority measures, such as for prevention of the spread of disease (Gunma, Ishikawa, and Ehime)
    • Priority measures have been implemented since May 16 in Gunma and Ishikawa. The number of infections have been in a decreasing trend from mid-May in Gunma, and it stopped increasing most recently in Ishikawa; the figures are about 24 and 29, respectively. The effective reproduction number is 1 or higher in both prefectures, and it is necessary to carefully monitor the changes in the number of cases of infection.
    • In Ehime, 3 weeks have passed since the start of priority measures. The number of new cases of infection has decreased since late April, reaching approximately 6.
  7. (7) Areas other than those listed above
    • The number of new cases of infection in Fukushima, Ibaraki, Yamaguchi and Kagawa exceeded 15, i.e., about 17, 16, 25 and 21 , respectively. A decreasing trend has been observed in Fukushima and Kagawa, and an increasing trend in Ibaraki. The effective reproduction number is 1 or higher, including Yamaguchi, and the situation should be carefully monitored.

Analysis of mutant strains

  • The proportion of the mutant strain first detected in the UK (B1.1.7) became about 80% in national total in screening test, suggesting that the existing strains were almost all replaced by the mutant strains, except for some regions. In addition, analysis of screening at private testing institutions by the National Institute of Infectious Diseases also demonstrates that the existing strains have already been replaced by the mutant strains in many regions.
  • It is necessary to establish medical care systems and provide treatments assuming the possibility of increased risk of disease becoming severer due to B.1.1.7.
  • In addition, it has been reported that B.1.617 (mutant strain detected first in India) is being replaced with the existing ones overseas, and it has been suggested that this strain may be more infectious than B.1.1.7. Therefore, it is necessary to continue analyses.

Measures to be taken

  • In some areas designated to be controlled under emergency measures and those under priority measures such as for prevention of the spread of disease, the number of infections seem to decrease or stop increasing owing to cooperation of citizens and business operators. On the other hand, there are some regions where the number of infections has not clearly decreased. In the spread of infection mainly of mutant strain (VOC) this time, it takes a longer time before a decrease in the flow of people results in a decrease in the number of new cases of infection. Currently, the effective reproduction number has not decreased to much lower than 1 with the previous efforts. It is required to discuss necessary measures based on the infection status and the high infectivity of mutant strains and to implement them in a timely manner.
  • In other regions, if the number of new cases of infection is at a high level and then increases/remains, the speed of infection will increase more than before and the burden on medical care provision systems will become larger. Therefore, necessary actions should be promptly taken.
  • It is crucial to proceed with measures in the early stages of the epidemic. Each local government is required to conduct measures promptly to establish a meeting structure to utilize advice of experts on public health and infectious diseases for countermeasures and to act from an early stage and establish a cooperative system to secure medical care provision systems based on future prospects by using various data, including the flow of people.
  • While it is estimated that the existing strains have been replaced with B.1.1.7 as the predominant strains in most regions with some exceptions, it is necessary to take measures focusing on understanding the actual situation using virus genomic surveillance in order to reinforce the measures against new mutant strains. Particularly for B.1.617, which has been positioned as VOC, it is essential to suppress the spread of infection in Japan as much as possible by following measures: nationwide monitoring through genomic surveillance, and active epidemiological surveys. In addition, the border control measures against infection from India, Pakistan, and Nepal have been strengthened. Prompt action will be required based on the occurrence status in other countries and quarantine.
  • In addition to the effect of vaccines to prevent onset of the disease, there have been reports suggesting effectiveness in the prevention of aggravation and infection. It is expected that vaccinations in wider populations can reduce severe cases and then inhibit infection of the virus. Vaccinations in the elderly has begun. It is expected that the vaccination both residents and workers in elderly facilities, etc. can suppress clusters. It is necessary for the national and local governments, with the cooperation of local medical associations, to work together to offer vaccinations for many people as quickly and efficiently as possible.

Figures (Number of new infections reported etc.) (PDF)

34th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (May 12, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has remained at the same level since the increase stopped based on the reporting date, and the number in the most recent week is approximately 31 per 100,000 population. The number based on the date of onset has also stopped increasing. Rather than the situation of nationwide infection spread, there are large regional differences, showing various trend as the number of infected patients surges in some areas and the number tends to decrease from steady-state situation in other areas. The number of severe cases and deaths continues to increase and is likely to further increase.

    The nationwide effective reproduction number is on a downward trend and has recently become 0.99 (as of April 25).

  • In the days ahead, the effect of the declaration of the state of emergency and the influence of the Golden Week holiday (GW) will be observed as an increase or decrease in the number of new cases of infection. However, it should also be noted that the number of reports after GW has increased due to the decrease in diagnosis and examinations and delayed reporting during GW.
Analysis of infection status [local trends]

*The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates. The effective reproduction number represents the mean value of the most recent week (as of April 25)

  1. (1) Kansai area
    • Mainly in Osaka and Hyogo, the medical care provision systems and the public health systems are under very severe pressure. Emergency transportation has continued to be more difficult in many cases, and it is still in such a critical situation that general medical care will be inevitably restricted. It has also become difficult to rapidly respond to worsened symptoms in patients recovering at home and receiving care at accommodation facilities. It is essential to keep a downward trend in the number of new cases of infection to protect the system for necessary and timely care.
    • In Osaka, Hyogo, Kyoto, and Nara, the number of new cases of infection is high in all age groups, especially those in their 20s and 30s. In Osaka, 5 weeks have passed since the start of implementation of the priority measures, such as for prevention of the spread of disease (hereinafter referred to as “priority measures”), and 2 weeks since the start of the emergency measures. The ratio of this week to last week has been 1 or lower for the most recent week and the number of new cases of infection has decreased, but remains extremely high at approximately 68.
    • In Osaka, the nighttime and daytime populations decreased rapidly to the minimum level at the time of the first declaration of the state of emergency, and then have stopped decreasing. The effective reproduction number in Osaka, Hyogo, and Kyoto is 0.88, 0.94, and 0.91, respectively. While the number of new cases of infection is expected to decrease in future, it is necessary to carefully monitor whether the decrease continues.
    • In Hyogo, Kyoto, Nara, and Wakayama, the number of new cases of infection is approximately 49, 33, 42, and 14, respectively, which, except for Wakayama, is still high but showing a downward trend. In Shiga, the number has increased again to a high level of approximately 25.
    • Local governments around the Kansai area also need to pay close attention to trends in the number of cases of infection.
  2. (2) Metropolitan area (Tokyo and its 3 neighboring prefectures) 
    • In Tokyo, 1 month and 2 weeks has passed since the start of the priority measures and the start of the emergency measures, respectively. In Saitama, Chiba, and Kanagawa, 3 weeks have passed since the start of the priority measures. In Tokyo and Saitama, it cannot be judged that the number of new cases of infection has stopped increasing. In Chiba and Kanagawa, the number has remained at the same level since the increase stopped. The number of new cases of infection in Tokyo, Saitama, Chiba, and Kanagawa is approximately 41, 21, 15, and 19, respectively. Many people are in their 20s to 50s. The ratio of this week to last week is on a downward trend at approximately 1 or lower after GW. The effective reproduction number is 1.10, 1.01, 1.09 and 1.02, respectively, and there is a possibility that a slight increase may continue at the same level.
    • In Tokyo, the spread of infection has continued mainly in central Tokyo and the neighboring areas. The nighttime and daytime populations continue to decrease, reaching a 25% lower level than the minimum value during the second declaration of the state of emergency. Although the downward trend has recently stopped, the number has not significantly increased.
    • In Saitama, Chiba, and Kanagawa, both the nighttime and daytime populations reached the minimum value during the second declaration, but the downward trend has stopped from late GW to after GW. In Chiba and Kanagawa, the daytime population has increased.
    • It is necessary to pay close attention to the future trend in the flow of people in the Tokyo metropolitan area and the impact of the decrease in the flow of people on the number of new cases of infection.
  3. (3) Chukyo area
    • In Aichi, 3 weeks have passed since the start of the priority measures while the emergency measures have been implemented as of today. The number of new cases of infection continues to increase, reaching approximately 40. The ratio of this week to last week has remained 1 or higher for 7 weeks from late March. The cases of infection are mainly of those in their 20s to 30s, but the number of new cases of infection tends to increase in almost all generations. The burden on medical institutions and public health centers is increasing and the medical care provision systems are under severe pressure. In Nagoya City, various clusters occurred in places such as restaurants, medical institutions, nursing facilities, schools, sports facilities, department stores, and community of foreigners.
    • The nighttime population continues to decrease to below the minimum level during the second declaration of the state of emergency. In contrast, the daytime population has increased from the latter half of GW. The effective reproduction number has remained 1 or higher, and the number of new cases of infection may continue to increase.
    • The priority measures were applied to Gifu and Mie from May 9, but the number of new cases of infection has surged in Gifu, reaching approximately 38. The number based on the date of onset also continues to increase. The ratio of this week to last week has remained 1 or higher for approximately 5 weeks from early April. The increase may continue in the days ahead. In Mie, the number of new cases of infection has been decreasing since the end of April. The ratio of this week to last week has been 1 or lower since May, and the number of new cases of infection has decreased to approximately 16.
  4. (4) Kyushu
    • In Fukuoka, the emergency measures began today. The number of new cases of infection has been rapidly increasing since mid-April mainly in people in their 20s to 30s, reaching approximately 57. The ratio of this week to last week has remained 1 or higher for 5 weeks from early April. The number of severe cases also considerably increased. The occupancy rate of beds is rapidly increasing and the burden on the medical care provision systems is increasing.
    • Although both the nighttime and daytime populations have decreased, they still have not reached the minimum level during the second declaration of the state of emergency. The effective reproduction number remains 1 or higher. Rapid increase in the number of new cases of infection may continue.
    • In each prefecture in Kyushu, the number of new cases of infection has also considerably increased and infection has spread throughout Kyushu. In particular, in Saga, Nagasaki, Kumamoto, Oita, and Miyazaki, the number of new cases of infection has been at a high level of approximately 42, 25, 34, 42, and 30, respectively. In Kagoshima, the number remains at the same level of approximately 21. In Nagasaki, Miyazaki, and Kagoshima, the ratio of this week to last week has been 1 or higher for 2 weeks, respectively. The effective reproduction number in the total of prefectures except Fukuoka is 1.00, but the number may continue to increase in consideration of the changes in the number of infected cases based on the reporting date.
  5. (5) Other areas under the priority measures, such as for prevention of the spread of disease (Hokkaido, Okinawa, and Ehime)
    • In Hokkaido, the priority measures were applied from May 9, but the number of new cases of infection continues to increase primarily in young people in Sapporo city, reaching a high level of approximately 47. The number of infected patients based on the date of onset may continue to increase. The number in Sapporo city is at a higher level of approximately 86 and infection has spread from Sapporo to various places in Hokkaido since the end of GW. The ratio of this week to last week has remained 1 or higher for approximately 5 weeks from early April. The effective reproduction number is high at 1.30. In addition, the medical care provision systems in Sapporo have been under severe pressure, and there have been cases of wide-area medical evacuation that were transported outside the city. Due to the influence of flow of people and meetings associated with GW, the infected cases reported from areas other than Sapporo are also increasing, and the spread of infection may occur in future. Further efforts are required to reduce the infection level in Hokkaido as a whole.
    • In Okinawa, one month has passed since the start of the priority measures. The number of new cases of infection was on a downward trend from mid-April, but is increasing again at a high level of approximately 38. Cases of infection are predominately those in their 20s to 30s. In the face of a serious shortage of beds, there is concern about an increase in the number of inpatients. Attention should be paid to the influence of movement of tourists associated with GW in the days ahead.
    • In Ehime, 2 weeks have passed since the start of implementation of the priority measures. The number of new cases of infection has decreased since late April, reaching approximately 10.
  6. (6) Areas other than those listed above
    • In other regions, the number of cases of infection has surged or continuously increased.
    • Particularly in Okayama and Hiroshima, the number of new cases of infection is very high at approximately 50 and 36, respectively. The ratio of this week to last week has remained 1 or higher for 6 weeks in Okayama and 4 weeks in Hiroshima, which is similar to the increase in the Kansai area and Aichi. The effective reproduction number is also high at 1.27 and 1.48, respectively, and there is a possibility that the spread of infection will continue in future. The population is relatively large and there is concern about the influence on the surrounding areas. Special efforts are required to reduce the infection level.
    • The number of new cases of infection exceeds 15 in Fukushima, Gunma, Ishikawa, Yamaguchi, and Kagawa. Particularly in Gunma, Ishikawa and Kagawa, the number of new cases of infection is high at approximately 28, 30, and 30, respectively. The effective reproduction number is 1.55, 1.10, and 1.68, respectively. In Gunma and Kagawa, the ratio of this week to last week has been 1 or higher for 2 weeks, and there is concern about influence on the medical care provision systems. Moreover, in Fukushima, the number of new cases of infection in the Aizu area has surged to over 50.

Analysis of mutant strains

  • The proportion of the mutant strain first detected in the UK (B1.1.7) in screening tests has exceeded approximately 70% in western Japan, suggesting that the existing strains were almost replaced by the mutant strains. Replacement of the predominant mutant strains is ongoing in other regions, e.g., approximately 60% in Tokyo and 80% in Hokkaido. In addition, analysis of screening at private testing institutions by the National Institute of Infectious Diseases demonstrates that the existing strains have been already replaced by the mutant strains in many regions.
  • No age-specific trend of infection spread has been seen. The number of pediatric patients is not remarkably high.
  • There is a finding that the risk of disease is becoming severer in persons aged 40 to 64 for B1.1.7 compared with non-N501Y mutations. Further close investigation is required to prove this.
  • In any case, it is necessary to establish medical care systems and provide treatments assuming the possibility of increased risk of disease becoming severer due to B1.1.7.

Measures to be taken

  • The declaration of the state of emergency has been extended and it is necessary to steadily suppress infection accordingly. To achieve this, people must steadily follow through with the recommendations associated with application of these measures in the areas designated to be under the emergency measures and the areas designated to be under the priority measures. In addition, the measures should be discussed in a timely manner considering the high infectivity of variants (VOC), followed by implementation.
  • Other than the above, the number of new cases of infection remains high in Okayama, Hiroshima and prefectures in Kyushu and the burden on the medical care provision systems has already been heavy in regions where the cases of infection have rapidly increased/been continuously detected. Necessary measures should be taken and strengthened immediately.
  • Furthermore, each local government is required to conduct measures promptly to establish a meeting structure to utilize advice of experts on public health and infectious diseases for countermeasures and to act from an early stage and establish a cooperative system to secure medical care provision systems based on future prospects.
  • Clusters have diversified not only in restaurants but also in other scenes of infection including workplaces, settings of club/group activities, and karaoke. Infection in the workplace is becoming noticeable, making it necessary to reduce the number of people working in the office by utilizing remote work and strengthen measures, such as avoiding eating places with infection risk when working in the office.
  • Information on the importance of basic infection prevention, such as wearing a mask, should be delivered. It is also necessary to inform that not only scenes with all of the “3Cs” (closed spaces, crowded places, and close contact settings), but scenes of 2 or one alone pose a risk of infection and should be avoided.
  • While replacement by B1.1.7 is ongoing, it is necessary to take measures focusing on understanding the actual situation using virus genomic surveillance in order to reinforce the measures against new mutant strains in line with local infection statuses and evaluations/analyses of epidemiological information. Particularly, for B.1.617 (the mutant strain first detected in India), which has been newly positioned as VOC, it is essential to suppress the spread of infection in Japan as much as possible by following measures: nationwide monitoring through genomic surveillance, strengthening of monitoring systems by performing PCR tests to detect L452R mutation, and active epidemiological surveys. In addition, the border control measures against infection from India, Pakistan, and Nepal have been strengthened. Prompt action will be required based on the occurrence status in other countries.
  • In addition to the proven effect of vaccines to prevent onset of the disease, there have been research reports conducted after clinical use of vaccines in various countries, suggesting effectiveness in the prevention of aggravation and infection. Vaccination with such effects in wider populations can be expected to reduce severe cases and then inhibit the infection of the disease. Vaccination was initiated for the elderly, but it is necessary for the national and local governments to work together to offer vaccinations for many people as quickly and efficiently as possible.

Figures (Number of new infections reported etc.) (PDF)

33th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (May 6, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide is still in an increasing trend based on the reporting date despite a decreasing trend in the ratio of this week to last week, and the number in the most recent week is approximately 28 per 100,000 population. The numbers of severe patients and deaths are rapidly increasing. As infections spread through the elderly population, the numbers are likely to further increase hereafter.

    The effective reproduction number exceeded 1 in late February and has recently become 1.02 (as of April 19).

  • Since mid-April, the proportion of young patients in their 20s to 50s among severe cases has increased not only in Osaka but also in Tokyo. Moreover, the number of infected persons aged less than 20 years has increased in many regions.
  • Furthermore, it should be assumed that the number of examinations and tests reduced during the Golden Week holidays; when the number of cases of infection increases in a region, because of the movements of people during the holidays in addition to delayed examinations and reporting, the number of reports in the following week or later is added with cases which may have occurred during the holidays.
Analysis of infection status [local trends]

*The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates

  1. (1) Kansai area: Mainly in Osaka and Hyogo, the medical care provision systems and the public health systems are under very severe pressure. Emergency transportation has become more difficult in many cases, and it is still in such a critical situation that general medical care will be inevitably restricted. It has also become difficult to rapidly respond to worsened symptoms in patients recovering at home and receiving care at accommodation facilities. It is essential to reduce the number of new cases of infection to protect the system for necessary and timely care.
    In Osaka, Hyogo, Kyoto and Nara, the number of new cases of infection is high in all age groups, especially in their 20s and 30s. In Osaka, 1 month and a little more than 10 days have passed since the start of implementation of the priority measures, such as for prevention of the spread of disease, and the emergency measures, respectively. The ratio of this week to last week has hovered around 1. There is a movement of decrease in the latest value of new cases of infection, but it is still very high, about 79. Careful monitoring should be continued for the situation as there is concern about delayed reporting.
    In Osaka, the nighttime and daytime populations that had decreased since application of the priority measures further decreased considerably and rapidly after issuance of the Declaration of State of Emergency. They hit a record low, below the lowest level observed under the first Declaration of State of Emergency. The effective reproduction number is 0.94 in Osaka, Hyogo and Kyoto, and the number of new cases of infection is expected to decrease. However, there is concern about delayed diagnoses and reporting, and an estimation that the value may level off. Therefore, the changes in the number of cases of infection should be carefully monitored at least through mid-May.
    For the neighboring regions, there is a movement of decrease in the number of cases of infection in Hyogo, Nara and Wakayama. The positive rate remains at high levels, around 15%, in Hyogo. It has leveled off in Kyoto and Shiga. The number of new cases of infection in Hyogo, Nara and Kyoto was as high as about 54, 42 and 35, respectively.
  2. (2) Metropolitan area (Tokyo and 3 prefectures):
    In Tokyo, three weeks and a little more than 10 days have passed since the start of implementation of the priority measures, such as for prevention of the spread of disease, and the emergency measures, respectively. With the spread of infection in persons in their 20s to 50s, the number of cases of infection is still in an increasing trend as a whole, to about 40. The ratio of this week to last week is also in a decreasing trend, but has continued to be 1 or higher for nearly 2 months. The spread of infection has continued mainly in the central Tokyo and also in neighboring areas.
    After issuance of the Declaration of State of Emergency, both the nighttime and daytime populations considerably and rapidly decreased. They reached levels below the lowest ever observed under the second Declaration of State of Emergency. The population between 18:00 to 20:00 in particular considerably decreased owing to voluntary restraint on serving alcoholic beverages. The decrease continued in the latter half of the Golden Week holidays. However, the effective reproduction number is not less than 1, and the number of new cases of infection may continue to increase after the Golden Week holidays.
    In Tokyo, the number of persons receiving medical care at accommodations or at home, and cases in the process of arranging hospitalization also increased, and there is concern about an increase in the burden on medical care provision systems.
    In Saitama, Chiba and Kanagawa, two weeks have passed since the start of implementation of the priority measures, such as for prevention of the spread of disease. The number of new cases of infection has leveled off or slightly increased, i.e., about 20, 16, and 17, respectively. The nighttime and daytime populations started to decrease during the Golden Week holidays. The population at 18:00 or later is continuing to decrease in the latter half of the Golden Week holidays owing to voluntary restraint on serving alcoholic beverages. The effective reproduction number is around 1, and the number of new cases of infection may remain flat for a while.
  3. (3) Chukyo area: In Aichi, 2 weeks have passed since the start of implementation of the priority measures, such as for prevention of the spread of disease. The increasing trend in the number of new cases of infection is continuing across almost all generations, but primarily in persons in their 20s and 30s, with the value reaching about 29. In Nagoya City, the number increased in almost all age groups, mainly in 30s to 50s.
    After issuance of the Declaration of State of Emergency this time for Tokyo and the Kansai area to which the emergency measures are taken, the population during both nighttime and daytime rapidly decreased. The nighttime population has become very close to the lowest value recorded during the second Declaration of State of Emergency. However, the effective reproduction number has continued to be 1 or higher for the most recent week, and the number of new cases of infection may continue to increase after the Golden Week holidays.
    In Gifu and Mie, the number of new cases of infection remains high, i.e., about 22 and 17, respectively.
  4. (4) Other areas under priority measures, such as for prevention of the spread of disease (Miyagi, Okinawa, and Ehime): In Miyagi, the decreasing trend in the number of new cases of infection is continuing with a current value of about 9. The nighttime and daytime populations decreased after issuance of the Declaration of State of Emergency.
    In Okinawa, the decreasing trend in the number of new cases of infection is continuing from mid-April, but is still high, about 31. The numbers in persons in their 20s and 30s is in a decreasing trend, but the numbers in persons in their 70s or older increased. Increase in the number of inpatients is a concern as hospital beds are nearly completely occupied.
    In Ehime, the number of new cases of infection started to decrease to about 12.
  5. (5) Areas other than those listed above: In Fukuoka, the number of new cases of infection has rapidly increased, primarily in persons in their 20s and 30s, since mid-April and reached about 47. The number of severe cases also considerably increased. The positive rate during the Golden Week holidays is increasing and there is concern about the spread and continuation of the infection. The number of new cases of infection hit a record high last week, and the nighttime and daytime populations have decreased since around that time. However, the values have not reached the lowest level achieved during the period of the second Declaration of State of Emergency. The effective reproduction number is at a high level, 1.35. Rapid increase in the number of new cases of infection may continue. Bed occupancy rate is also rapidly increasing. It may lead to the spread of infection as in the Kansai area, and prompt actions are needed.
    In Oita, Saga and Nagasaki, movements of decrease, and then of re-increase were observed. Although there is a movement of decrease in Kumamoto, the cases of infection are increasing in Miyazaki, and a rapid increase was observed from late April in Kagoshima, indicating the spread of infection all over the Kyushu area.
    The number of new cases of infection has continued to increase in Hokkaido, mainly in Sapporo City, and reached a high level of about 28. The value is high, about 57 in Sapporo City. Severely ill patients in their 50s or younger, especially 40s, are increasing, and the number of inpatients exceeded that during the third wave. The use rate of beds exceeded 80% and there have been cases of wide-area medical transportation to outside the City. The effective reproduction number is at a high level, 1.41. The rapid increase in the number of new cases of infection is expected to continue after the Golden Week holidays.
    In other regions, the number of cases of infection has surged or continuously increased due to clusters, etc. The number of new cases of infection exceeded 15 in Fukushima, Gunma, Ishikawa, Okayama, Hiroshima, Tokushima and Kagawa. Particularly in Gunma, Okayama and Tokushima, the number of new cases of infection is high, i.e., about 25, 33, and 27, respectively (the ratio of this week to last week has been 1 or higher for 2 weeks or longer in Ishikawa, Okayama, Hiroshima and Kagawa.). Especially in Gunma, the effective reproduction number is high, 1.42, and there is concern that the rapid increase may continue.

Analysis of mutant strains

  • The proportion of mutant strains as variants of concern (VOC) remains high, exceeding 80%, in the Kansai area (Osaka, Kyoto, and Hyogo); such strains seem to have been replaced with existing ones. Replacement of the predominant variants is ongoing in other regions, e.g., about 60% in Tokyo and 70% in Aichi.
  • No age-specific trend of infection spread has been seen. The number of pediatric patients is not remarkably high.
  • There is a finding that the risk of disease becoming severer in persons in their 50s or younger for variants with N501Y mutation than with non-N501Y mutation. Further close investigation is required to prove it.
  • In any case, it is necessary to establish medical care systems and provide treatments assuming the possibility of increased risk of disease becoming severer due to variants with N501Y mutation.

Measures to be taken

  • A little more than 10 days have passed since issuance of the Declaration of State of Emergency. In the regions under the measures for the State of Emergency (Tokyo, Osaka, Kyoto and Hyogo), the nighttime population decreased and a movement towards decrease in the rate of this week to last week has been observed. However, the increasing trend in the number of cases of infection is continuing in Tokyo, and the number has leveled off or slightly increased in Saitama, Chiba and Kanagawa designated to be controlled under priority measures, such as for prevention of the spread of disease. In the Kansai area, the number of cases of infection has leveled off or appears to be decreasing. However, the medical care provision systems are still in critical conditions. Based on the situation that the priority measures, such as for prevention of the spread of disease, had only limited effects while the existing strains have been replaced with mutant strains (VOC), strong measures are required again for ordinary times after the end of the Golden Week holidays.
  • In the other areas under priority measures such as for prevention of the spread of disease, the number of cases of infection has continued to increase in Aichi, is in a decreasing trend but remains high, about 30 in Okinawa. Effective measures to inhibit the infection are required. In Miyagi, the decreasing trend in the number of cases of infection is continuing, peaking at early April, and the use rate of beds has also decreased. The decreasing trend has continued since late April also in Ehime. In these areas, measures to prevent recurrences are required.
  • The number of new cases of infection remains high in Fukuoka and Hokkaido, and the burden on the medical care provision system has already been heavy in regions where the cases of infection have rapidly increased/been continuously detected. Strong measures to inhibit the infection should be taken immediately.
  • Considering the effects of mutant strains (VOC), it is considered necessary to discuss the timings and details of such measures based on the effects of the measures having been taken so far in various regions including Osaka and Tokyo.
  • Clusters have diversified not only in restaurants but also in other scenes of infection including workplaces and settings of club/group activities. Cases of infection in workplaces are becoming prominent and social activities will resume after the Golden Week holidays. It is required to reinforce the measures to inhibit the infection, such as continuing to limit commuting after the Golden Week holidays by utilizing teleworking, etc.
  • The information on the importance of basic infection prevention, such as wearing a mask, should be delivered. It is also necessary to inform the differences in the characteristics of masks by materials, e.g., non-woven fabric. It is also necessary to inform that not only scenes with the “3Cs” (closed spaces, crowded places, and close contact settings) but scenes of two or one of them alone pose a risk of infection.
  • While the previously predominant strains have been replaced with mutant strains (VOC), it is necessary to take measures focusing on understanding of the actual situation using virus genomic surveillance in order to reinforce the measures against new mutant strains in line with local infection statuses and evaluations/analyses of epidemiological information.
  • In addition to the proven effect of vaccines to prevent onset of the disease, there have been research reports conducted after clinical use of vaccines in various countries, suggesting the effect to prevent aggravation or to prevent infection. Vaccination with such effects in wider populations can be expected to reduce severe cases and then inhibit the infection of the disease. Vaccination was initiated for the elderly, but it is necessary for the national and local governments to work together to offer vaccinations for many people as quickly and efficiently as possible.

Figures (Number of new infections reported etc.) (PDF)

32th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (April 27, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has continued to increase based on the reporting date despite a tendency of decrease in the ratio of this week to last week, and the number in the most recent week is approximately 27 per 100,000 population. In addition to the Kansai Area, Tokyo Metropolitan Area, and Chukyo Area, the number of persons with infection is increasing in many local areas. With the increase in the number of new cases of infection, the number of severe patients has rapidly increased, and the number of deaths also started to increase. Spread of infection to the elderly may further increase the number of severe patients.

    The effective reproduction number exceeded 1 in late February and has recently become 1.10 (as of April 10). The level remains below 1 in Miyagi and Okinawa, but above 1 in Tokyo and its 3 neighboring prefectures, as well as Aichi, Osaka and Hyogo as of April 11.

  • The proportion of mutant strains as variants of concern (VOC) remains high, around 80%, in the Kansai area (Osaka, Kyoto, and Hyogo); such strains seem to have been replaced with the existing ones in the recent spread of infection. The proportion has been increasing to about 40% in Tokyo and about 60% in Aichi, and also in other regions. It is expected that the predominant strains will change all over Japan. No obvious trend of infection spread has been seen in persons aged less than 15 years. The number of pediatric patients is not remarkably high in the recent spread of infection.
  • In Osaka, it has been pointed out that the rate of severe cases has become high in patients aged 40 years or older, but there is a possibility of increase in the proportion of mutant strains or mild cases no longer diagnosed, and therefore it is necessary to continuously monitor the situation.
Analysis of infection status [local trends]

*The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates

  1. (1) Kansai area: Especially in Osaka, Hyogo and Nara, the medical care provision systems and the public health systems are under very severe pressure. Emergency transportation will become more difficult in many cases, making the need for restrictions on general medical care inevitable. To protect the system to provide necessary medical care, it is essential to reduce the number of new cases of infection.
    In Osaka, Hyogo, Kyoto and Nara, the number of new cases of infection is high in all age groups, predominately 20s and 30s. Three weeks have passed since the start of priority measures, such as for prevention of the spread of disease in Osaka, and the emergency measures were adopted again on April 25. The daytime and nighttime population downtown decreased, close to that under the previous Declaration of State of Emergency. The ratio of this week to last week is still decreasing. Although the number of new cases of infection remains at a very high level, about 88. The numbers of inpatients and severe patients are expected to increase further (the proportion of severe patients in their 40s and 50s also increased). In the surrounding prefectures, the number of new cases of infection is increasing in general, i.e., about 64, 38, 49, 26 and 23 in Hyogo, Kyoto, Nara, Wakayama and Shiga, respectively (in Shiga, the ratio of this week to last week has continued to be 1 or more for 2 weeks or longer).
    In Osaka, the infection route is unknown in more than 60% of cases and infections in such places as households, workplaces, and settings of club/group activities, as well as elderly facilities, have been observed.
  2. (2) Metropolitan area (Tokyo and 3 prefectures): Two weeks have passed since the start of priority measures, such as for prevention of the spread of disease in Tokyo, and the emergency measures were adopted again on April 25. The nighttime population began to decrease but seems to have bottomed out recently, and it is not lower than that under the previous Declaration of State of Emergency. With the spread of infection in persons in their 20s to 50s, the number of cases of infection is increasing as a whole, to be about 37. The ratio of this week to last week has been 1 or higher for a month or longer. The infection is spreading from the center of Tokyo to its surrounding areas. It is necessary to watch carefully whether infection will decrease.
    In Tokyo, infection is spreading at restaurants, in addition to cases of infection in facilities, settings of club/group activities, and workplaces. The number of persons receiving medical care at accommodations or at home, and cases in the process of arranging hospitalization has started to increase, and there is concern about an increase in the burden on the medical care provision systems in future.
    In Saitama, Chiba and Kanagawa, the ratio of this week to last week decreased, but the number of new cases of infection is rising. The number of cases of infection is expected to increase until the measures for prevention of the spread of disease begin to show their effect.
  3. (3) Chukyo area: In Aichi, the number of new cases of infection has reached about 24, resulting from increases in almost all generations in their 60s or younger, mainly in persons in their 20s and 30s. In Nagoya City, the figure has increased in persons in all age groups, mainly in their 30s to 50s, and infection has been seen in elderly facilities, settings of club/group activities, workplaces, and communities of foreigners.
    In Mie and Gifu, the number of cases of infection increased to about 21 and 14, respectively. The ratio of this week to last week has been 1 or higher for 2 weeks or longer.
    In Aichi, the proportion of mutant strains (VOC) is about 60%, and sporadic cases and clusters caused by mutant strains have occurred frequently. Although the nighttime population began to decrease, there is still concern about continued spread of infection.
  4. (4) Other areas under priority measures, such as for prevention of the spread of disease (Miyagi, Okinawa): In Miyagi, the decreasing trend in the number of new cases of infection is continuing with a current figure of about 13. The flow of people until 20:00 is showing an increasing trend and this should be watched carefully.
    In Okinawa, the number of new cases of infection began to decrease in mid-April, but is still high, about 44. The number of patients in their 20s and 30s is decreasing, the patients in their 70s increased, and the number of inpatients is increasing.
  5. (5) Areas other than those listed above: In Fukuoka, the nighttime population began to decrease, but the number of new cases of infection has rapidly increased, primarily in persons in their 20s and 30s, since mid-April, reaching about 34. The ratio of this week to last week is above 2. The numbers of cases of infection have rapidly increased since mid- to late April in Saga, Nagasaki, Kumamoto and Oita, to about 22, 14, 16 and 26, respectively (the ratio of this week to last week has been 1 or higher for 2 weeks or longer in Fukuoka, Saga, Kumamoto and Oita). There is concern about the continued or rapid spread of infection throughout Kyushu.
    In other regions, the number of infections has surged, or has continuously increased due to clusters, etc. The number of new cases of infection is increasing or remains high, i.e., above 10, in Hokkaido, Aomori, Fukushima, Ibaraki, Gunma, Niigata, Toyama, Ishikawa, Fukui, Okayama, Yamaguchi, Tokushima, Kagawa and Ehime. Especially in Hokkaido, Ibaraki, Ishikawa, Fukui, Okayama, Tokushima and Ehime, the numbers of new cases of infection are at high levels, i.e., 18, 15, 17, 15, 21, 34 and 18, respectively (the ratio of this week to last week has been 1 or higher for 2 weeks or longer in Hokkaido, Ibaraki, Ishikawa, Okayama and Tokushima).

Measures to be taken

  • A Declaration of a State of Emergency was announced. Expansion of infection must be reduced during the Golden Week holidays with the actions based on the Declaration, and infection should be suppressed by taking this opportunity. To achieve this, people must steadily follow through with the recommendations under the emergency measures and discuss future measures in line with the effects achieved in the areas designated to be under the measures for the emergency state (Tokyo, Osaka, Kyoto and Hyogo) and the areas designated to be under priority measures, such as for prevention of the spread of disease (Miyagi, Saitama, Chiba, Kanagawa, Aichi, Ehime, and Okinawa).
  • In other regions where the number of cases of infection is increasing, it is necessary to promptly make efforts to control the infection while carefully monitoring the infection status in each area. Based on such measures, it is required to secure medical care provision systems and public health systems to respond to further spread of infection, as well as to provide necessary support by the national government.
  • There is a nationwide trend of infection spread in working generations who are active in their lifestyles, mainly in their 20s and 30s. Moreover, clusters have diversified not only in restaurants but also in other scenes of infection including workplaces and settings of club/group activities. To control infections under such circumstances, it is necessary to take thorough measures at places where clusters are likely to occur, and to take measures to largely reduce the opportunities of contact by steadily suppressing the flow of people and movement across prefectures as the Golden Week holidays approach, especially in the areas under the emergency measures or under priority measures, such as for prevention of the spread of disease.
  • Cases of infection in workplaces have become more prominent, occurring more frequently than before. It is necessary to organize systems of medical care in which workers, including non-regular employees, can feel safe enough to visit a hospital and undergo a test when they have any symptom of the disease, and reinforce the countermeasures such as teleworking and limitation on commuting.
  • In addition, clusters have frequently occurred in medical facilities and welfare facilities with the increase in infected patients. It is also important to prevent infection among facility personnel. A system for prompt testing, even in persons with mild symptoms, should be organized in addition to thorough implementation of preventive measures against infection and quick responses to the occurrence of infection, as well as periodic testing for personnel. Clusters have also occurred in communities of foreigners, requiring swift responsive action.
  • It is necessary to urge patients with symptoms to undergo the test followed by rapid conduct of the test. It is also necessary to organize a system for consultation and rapid testing during the Golden Week holidays. Furthermore, the importance of basic infection prevention, such as wearing a mask, should be reiterated.
  • Timely and prompt action is required based on evaluations/analyses of epidemiological information on the regional status of infection, infectivity, and pathogenicity while the existing strains have been replaced with mutant strains (VOC) as the predominant source of infection. It is necessary to grasp the actual state of new mutant strains using virus genome surveillance and take appropriate actions based on evaluations and analyses.

Figures (Number of new infections reported etc.) (PDF)

31th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (April 20, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has continued to increase since early March based on the reporting date, and the number in the most recent week is approximately 23 per 100,000 population. In addition to the Kansai Area, Tokyo Metropolitan Area, and Chukyo Area, the number of persons with infection is increasing in many local areas, and the rate of increase continues to be high. With the increase in the number of new cases of infection, the number of severe patients has rapidly increased from late March.

    The effective reproduction number exceeded 1 in late February and has recently reached 1.11 (as of April 3) The level remains below 1 in Miyagi, but above 1 in Tokyo and its 3 neighboring prefectures, Aichi, Osaka/Hyogo, and Okinawa as of April 4.

  • There is still an increasing trend in the number of persons infected with the mutant strain N501Y, designated as a variant of concern (VOC). The proportion of mutant strains (VOC) detected by screening test (mechanical calculation) has risen to approximately 80% in Osaka and Hyogo and approximately 30% in Tokyo, showing that the strains are rapidly replacing the existing strains. At present, there is no clear trend toward spread of infection in persons aged less than 15 years.
[Local trends]

*The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates.

  1. (1) Metropolitan area (Tokyo and its 3 neighboring prefectures): The number of new cases of infection has continued to increase since mid-March to approximately 30 in Tokyo. The cases in their 20s to 30s have increased markedly, and the ratio of this week to last week has remained 1 or higher beyond 1 month. The proportion of mutant strains (VOC) also increased. In Kanagawa and Saitama, the number of new cases of infection has continued to increase since April, and in Chiba, the figure has also started to increase since mid-April.
  2. (2) Kansai area/Chukyo area/Kyushu: The prevalent strains have been replaced with mutant ones in the Kansai area. Moreover, the number of cases of infection is increasing in all generations, especially in the those in their 20s and 30s. The number of cases of infection has rapidly increased since mid-March in Osaka and Hyogo, and the figure has also considerably increased since late March in Kyoto, Nara, and Wakayama. After that, the number has also surged in Shiga. In Osaka, the rate of increase has slowed, but the ratio of this week to last week was 1.31 and the number of new cases of infection was approximately 88, showing no decrease. In particular, in Osaka, Hyogo, and Nara, the medical care provision systems and the public health systems have been put under extremely severe pressure with the upsurge in numbers of new cases of infection.
    In Aichi, the number of new cases of infection has reached approximately 18, resulting from increase in almost all generations in their 60s or younger, mainly in persons in their 20s and 30s. The rate of increase also remains high. The number has also increased in Gifu and Mie.
    In Fukuoka, the figure has rapidly increased since mid-April reaching approximately 16, and there is also an increase in Saga and Nagasaki.
  3. (3) Areas other than those listed above: In Okinawa, the infection has rapidly spread since late March. The number of new cases of infection has leveled off since mid-April, but remains at a high level of approximately 54. While the proportion of persons with infection in their 20s to 50s is large, the number of inpatients has increased.
    In Miyagi and Yamagata, the figure started decreasing after the end of March, showing decrease in all generations in Miyagi.
    In other regions, the number of infections has surged, or has continuously increased due to clusters, etc. In Hokkaido, Aomori, Fukushima, Ibaraki, Gunma, Ishikawa, Fukui, Nagano, Gifu, Okayama, Tokushima and Ehime, the number of new cases of infection remains high exceeding 10, and in particular, in Tokushima and Ehime, the number is high at 31 and 18.

Analysis of infection status

  • In the Kansai area, the existing strains have been replaced by mutant strains and the spread of infection continues. The number of persons with infection continues to increase not only in Osaka and Hyogo but also in the neighboring local areas, and attention needs to be paid to a rapid increase in the number of cases of infection due to mutant strains (the proportion of severe patients in their 40s and 50s also has increased in Osaka). In Osaka, the infection route is unknown in more than 60% of cases, and infections in households, workplaces, and settings of club/group activities have been observed. In Osaka, 2 weeks after the start of the priority measures, such as for prevention of the spread of disease, nighttime population in downtown areas tends to be on a downward trend, and the increase rate has also decreased. However, the number of new cases of infection has continuously increased and it is expected that the number of persons with infection, number of inpatients, and number of severe patients will continue to increase in the future. The number of cases in which the coordination of emergency transportation is difficult has been increasing and medical care provision systems are already under extremely severe pressure. The necessary measures must be implemented more thoroughly and the necessary support should be provided.
  • In the Tokyo metropolitan area, the nighttime population rapidly increased in Tokyo after the Declaration of a State of Emergency was lifted. The number of cases of infection began to decrease thereafter, but the infection spread in those in their 20s and 50s, and the total cases of infection are increasing and the increase rate has also elevated. There is a spread mainly in the central Tokyo and also in neighboring areas. Infection continues to spread at restaurants, and infected cases in facilities, settings of club/group activities, and workplaces are observed. The proportion of mutant strains (VOC) detected by screening tests is also increasing, reaching approximately 30%. The decrease in the nighttime population in downtown areas was limited, which was seen only in hours from 8:00 p.m. to 10:00 p.m. The effects of the priority measures, such as for prevention of the spread of disease have not been clarified yet, and there are concerns about continuous spread of infection and rapid expansion. In addition, the number of persons receiving medical care at accommodations or at home, and cases in the process of arranging hospitalization has started to increase, and there is concern about an increase in burden on the medical care provision systems in the future. In Tokyo and its 3 neighboring prefectures, the priority measures, such as for prevention of the spread of disease became effective from today. There has been no clear trend toward a decrease in flow of people, and the number of persons with infection is estimated to increase for approximately 2 weeks hereafter.
  • In Aichi, the number of cases of infection has increased since late March mainly in people in their 20s and 30s, and the proportion of mutant strains (VOC) detected by a screening test also is above approximately 50%. In Nagoya City, the figure has increased in people in their 10s to 60s, and infection has been seen in facilities, settings of club/group activities, workplaces, and communities of foreigners. An increase in the number of persons with infection has been also seen in neighboring Mie and Gifu, and it is considered that a certain period will be required for taking effects of the priority measures, such as for prevention of the spread of disease, which became effective from today. There are concerns about continuous expansion of infection or rapid expansion.
  • In Fukuoka, the number of persons with infection mainly in their 20s to 30s has been rapidly increasing since mid-April and nighttime population is also increasing. In neighboring Saga and Nagasaki, there has also been an increase in the number of persons with infection, which brings on anxiety for continuous spread of infection and rapid expansion of infection.
  • In Miyagi, the number of new cases of infection has decreased in association with a decline in the flow of people in the night after 8:00 p.m. However, the flow of people up to 8:00 p.m. has been increasing, and attention should be paid to future trends.
  • The spread of infection is due to the increase in infected persons in their 20s and 30s in most areas. In some areas, the number of persons with infection increases in all generations. As infections spread through the elderly population, severe cases are likely to further increase hereafter.

Measures to be taken

  • In areas under the priority measures, such as for prevention of the spread of disease (Miyagi, Tokyo, Saitama, Chiba, Kanagawa, Aichi, Osaka, Kyoto, Hyogo, and Okinawa), actions to be taken for the application of the priority measures should be implemented steadily. Then, expansion of infection must be reduced during the Golden Week holidays, and infection should be suppressed by taking this opportunity. In particular, in areas where infection is expanding, it is necessary to adopt measures not only in restaurants at night but also in workplaces and settings of club/group activities. Further, concrete measures to reduce flow of people should be implemented.
  • In particular, in Osaka and Hyogo, the strains have already been replaced by mutant strains (VOC), resulting in a large number of persons with infection in all generations. The medical care provision systems have been under extremely severe pressure, and securing beds and healthcare professionals for patients in severe conditions, which are expected to increase, should be prioritized. Flexible support by the national government is also required. Together with ensuring efforts at restaurants, strengthened measures are required to further reduce contact with others.
  • In Tokyo, the number of persons with infection in their 20s to 50s has been increasing, and the effects of the priority measures, such as for prevention of the spread of disease, have not been clarified yet. There is a possibility of rapid expansion of infection as in the Kansai area in future, which causes concerns that this may overwhelm medical settings and have major effects on usual medical care. In addition, as the Tokyo metropolitan area has a significant impact on other areas through movement of people, strengthened measures to reduce contact with others and movement of people should be considered.
  • In other regions where the number of cases of infection is increasing, it is necessary to promptly make efforts to control the infection in view of the infection status. Based on such measures, it is required to secure medical care provision systems and public health systems to respond to further spread of infection, as well as to provide necessary support by the national government.
  • There is a nationwide trend of infection spread mainly in people in their 20s and 30s. Infection has been reported not only in restaurants but also in various settings such as workplaces and club/group activities. Infection control to reduce expansion in this generation is required and attention should be paid to the spread of infection to the elderly population. There has continuously been infection at daytime karaoke and restaurants. The communities of foreigners also needed attention. It is necessary to urge patients with symptoms to undergo the test followed by rapid conduct of the test. In addition, it is needed to communicate again the importance of basic infection prevention such as wearing a mask.
  • As the number of infected people increases, it is important to prevent infection among the personnel in medical and welfare facilities. Therefore, a system for prompt testing even in persons with mild symptoms should be organized, in addition to thorough implementation of preventive measures against infection and quick response to the occurrence of infection, as well as periodic testing for personnel.
  • The mutant strain N501Y (VOC) has been reported to have higher infectivity than the existing strain. Prompt action is required based on evaluations/analyses of epidemiological information on the regional status of infection, infectivity, and pathogenicity considering the recent increase in the number of cases of infection.

Figures (Number of new infections reported etc.) (PDF)

30th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (April 14, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has continued to increase since early March based on the reporting date, and the number in the most recent week is approximately 18 per 100,000 population. With a rapid increase in the Kansai area, the rate of increase has risen since late March. With the increase in the number of new cases of infection, the number of severe patients has been increasing from late March.  

    The effective reproduction number exceeded 1 in late February and has recently reached 1.18 (as of March 28). The figure was below 1 on March 27 in Miyagi, and above 1 in Tokyo and its 3 neighboring prefectures, Osaka, Hyogo, Kyoto, and Okinawa; of which Osaka, Hyogo and Kyoto were particularly high at 1.54.

  • There is still an increasing trend in the number of persons infected with the mutant strain N501Y, designated as a variant of concern (VOC). In particular, many cases of infection have been reported in Osaka and Hyogo. The proportion of mutant strains (VOC) detected by screening tests, which are just based on mechanical estimate, remains high and the number of persons infected with mutant strains (VOC) is also increasing in the surrounding areas. The proportion has increased not only in the Kansai area but in many other areas including Tokyo and Aichi, indicating rapid replacement in predominant strains of the novel coronavirus in Japan.
[Local trends]

*The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates.

  1. (1) Metropolitan area (Tokyo and its 3 neighboring prefectures): The number of new cases of infection has continued to increase since mid-March to approximately 25 in Tokyo. The proportion of mutant strains (VOC) also increased. The number of new cases of infection started to increase in April in Kanagawa and Saitama while remaining stable/decreasing in Chiba, and it is at a high level in and around Tokyo. In Tokyo, the number of inpatients took an upturn in mid-March, the use rate of beds increased, and the cases of hospitalization/medical care being adjusted are increasing.
  2. (2) Kansai area/Chukyo area/Kyushu: The prevalent strains have been replaced with mutant ones in the Kansai area. Moreover, the number of cases of infection are increasing in all generations, especially in the those in their 20s and 30s. Furthermore, the number of cases of infection has rapidly increased since mid-March in Osaka and Hyogo, and the figure has also considerably increased since late March in Kyoto, Nara, and Wakayama. In Osaka, the infection is spreading in cities, other than Osaka City, despite a decrease in the rate of increase, and the number of new cases of infection is approximately 71. In Osaka and Hyogo, the overall use rate of beds and the use rate of beds by patients in severe conditions are continuously increasing with the upsurge in number of new cases of infection, putting the medical care provision systems under very severe pressure. In Aichi, the number of new cases of infection is increasing mainly in persons in their 20s and 30s from late March, i.e., approximately 15. The rate of increase also remains high. In April there have also been signs of increase in Fukuoka, and the rate of increase is rising.
  3. (3) Areas other than those listed above: In Okinawa, the infection has rapidly spread since late March. Although the rate of increase lowered, the number of new cases of infection is approximately 57. While the proportion of persons with infection in their 20s to 50s is large, the number of inpatients has increased. The infection had rapidly spread in Miyagi and Yamagata, however, the number of new cases of infection began to decrease at the end of March to approximately 27 and 15, respectively. In Yamagata, the proportion of elderly patients with infection increased and bottomed out, and the progress should be carefully monitored. In Fukushima, the number of persons with infection in their 20s and 30s rapidly increased. The number of infections due to clusters, etc. rapidly increased in some other regions. Furthermore, in the Shikoku area, the number of cases of infection remains high due to an increase in infected persons in their 20s and 30s in Ehime, and the figure is also increasing in Tokushima.

Analysis of infection status

  • The spread of infection is due to the increase in infected persons in their 20s and 30s in most areas. Spread of infection to the elderly may increase the number of severe patients in the future.
  • The status of infection varies from region to region, not uniformly nationwide, and it is necessary to take actions based not only on national trends but also on trends of infection in each region.
  • There is still great concern that the infection may spread in the Kansai area. The number of cases of infection is increasing not only in Osaka and Hyogo, but also in the surrounding areas. Attention should be paid to the rapid increase in the number of cases of infection with mutant strains in the surrounding areas as well. The flow of people is decreasing in Osaka, however, it will take a certain period of time to see a decrease in the number of new cases of infection. Continued spread of infection and increase in the number of inpatients are also expected. Medical care provision systems are already under severe pressure. The necessary measures must be implemented more thoroughly and the necessary support provided.
  • In the Tokyo metropolitan area, the nighttime population rapidly increased in Tokyo after the Declaration of a State of Emergency was lifted. The number of cases of infection began to decrease thereafter, but the infection spread in those in their 20s and 30s, and the total cases of infection are increasing. In the Kansai area, primarily in Osaka and Hyogo, the flow of people increased after the measures including the requests for shortening of business hours under the Declaration of State of Emergency were lifted, and the infection spread from around 3 weeks after the lifting of such restrictions. The proportion of mutant strains (VOC) detected by a screening test is showing an increasing trend in Tokyo and there is concern that the infection may spread continuously or rapidly in metropolitan areas, such as Tokyo, as in the Kansai area.
  • In Aichi, the number of cases of infection has increased since late March mainly in people in their 20s and 30s, and the proportion of mutant strains (VOC) detected by a screening test is also increasing. There is also an increase in infected persons in the neighboring prefectures of Mie and Gifu with concern for even further spread of infection.
  • The government of Okinawa initiated its own measures. Although the increase in the number of cases of infection slowed down, the increasing trend continued, and the infection is spreading mainly in young people. The progress in these trends should be monitored from now on.
  • The places of clusters are diverse, including medical institutions, welfare facilities, schools, workplaces, restaurants, scenes of eating and drinking, and sports. Clusters have occurred in restaurants and karaoke bars during the day. Such clusters should be carefully monitored.

Measures to be taken

  • In regions which were designated as areas subject to priority measures, such as prevention of the spread of infection in view of the rapid spread of infection (Miyagi, Tokyo, Osaka, Kyoto, Hyogo, and Okinawa), necessary measures should be steadily taken including thorough patrols and requests for restaurants, including the shortening of business hours to 20:00, which should be implemented in application of this measure, as well as priority testing, securing medical care provision systems, and requesting restaurants to refrain from using karaoke equipment. Particularly in Osaka and Hyogo, reported cases of mutant strains (VOC) increased among many cases of infection reported. The medical care provision systems have already been under severe pressure, and securing beds and healthcare professionals for patients in severe conditions, which are expected to increase, should be prioritized. Flexible support by the national government is also required. The infection is rapidly spreading beyond Osaka City to neighboring Kyoto, Nara, and Wakayama. Avoidance of non-essential and non-urgent outings and movements are crucial to prevent spread of mutant strains associated with movements of people to other regions. Prompt and appropriate measures should be additionally taken as needed in view of the status of infection, changes in the flow of people, and the conditions of medical care provision systems. It is also required to conduct analyses of the causes of the spread of infection and take measures against the spread of infection based on these analyses.
  • For the Tokyo metropolitan area, the number of cases of infection is increasing in Tokyo as well as Saitama and Kanagawa. There is much concern surrounding the future course of the disease considering the nighttime population and the proportion of mutant strains detected. As in the Kansai area after lifting of the Declaration of State of Emergency, the infection may rapidly spread not only in Tokyo but to its surrounding areas. It is necessary to promptly organize testing/consultation systems assuming re-spread of infection and medical care provision systems including recuperation at accommodation facilities and at home, as well as sufficient and timely measures responding to the infection status.
  • In other regions where the number of cases of infection is increasing such as Aichi, it is necessary to promptly make efforts to control the infection while carefully monitoring the infection status. It is of the utmost importance that certain measures be taken, such as requests to shorten the business hours of restaurants and patrols, requests asking people to avoid going out, improvements for systems to conduct tests without delay, and prompt surveys of close contacts and the sources of infection. Based on such measures, it is necessary to secure medical care provision systems and public health systems to respond to further spread of infection, in addition to support by the national government.
  • There is a nationwide trend of infection spread mainly in people in their 20s and 30s. It is necessary to control the causes of the spread of infection in this generation and to be alert to the spread of infection to the elderly. In order to prevent the spread of infection, it is necessary to ask people to avoid getting together in places such as the 3Cs (closed spaces, crowded places, and close contact settings), and parties associated with various events. Furthermore, for the prevention of infection, people should be appropriately informed of the risk of infection in situations where the elderly get together, such as daytime karaoke and product sales with customer service, eating and drinking together for a long time during the day, and actual situations of clusters. In addition, it is necessary to urge patients with symptoms to undergo the test followed by rapid conduct of the test.
  • As the number of infected people increases, it is important to prevent infection among the personnel in medical and welfare facilities. Therefore, a system for prompt testing in staff members with mild symptoms should be organized, in addition to thorough implementation of preventive measures against infection and quick response to the occurrence of infection, as well as periodic testing for personnel.
  • Prompt action regarding the mutant strain N501Y (VOC) are required based on evaluations/analyses of epidemiological information on the regional status of infection, infectivity, and pathogenicity considering the recent increase in the number of cases of infection.

Figures (Number of new infections reported etc.) (PDF)

29th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (April 7, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide has continued to increase since early March based on the reporting date, and the number in the most recent week is approximately 14 per 100,000 population. With a rapid increase in the Kansai area, the rate of increase is rising from late March. The number of patients with severe symptoms took an upturn in late March with increases in the number of new cases of infection. Attention should be paid to the speed of increase in severe cases.

    The effective reproduction number: exceeded 1 in late February and has recently reached 1.16 (as of March 21). The figure reached above 1 on March 22 in Miyagi, Tokyo and its 3 neighboring prefectures, as well as Aichi and Gifu, Osaka, Hyogo and Kyoto; especially in the latter 3 where it has risen to 1.74.

  • There is still an increasing trend in the number of persons infected with the mutant strains such as N501Y, designated as a variant of concern (VOC), and clusters have continued to occur. In particular, many cases of infection have been reported in Osaka and Hyogo. The proportion of mutant strains (VOC) detected by screening tests, which are just based on mechanical estimate, remains high and the number of persons infected with mutant strains (VOC) is also increasing in the surrounding areas.
[Local trends]

*The value of new cases of infections is the number of people per 100,000 in the total number for the latest week on the basis of reporting dates.

  1. (1) Metropolitan area (Tokyo and its 3 neighboring prefectures) The number of new cases of infection has continued to increase since mid-March to approximately 20 in Tokyo. A sign of increase has been observed in Kanagawa and Saitama from the beginning of April while the figure remains stable in Chiba. The burden on medical care provision systems has been reduced. In Tokyo, the number of inpatients made an upturn in mid-March, the use rate of beds increased, and the cases of hospitalization/medical care being adjusted are increasing.
  2. (2) Kansai area/Chukyo area/Kyushu There have been more reports on mutant strains in the Kansai area. Furthermore, the number of cases of infection has rapidly increased since mid-March in Osaka and Hyogo with an increase in the flow of people, and the figure has also considerably increased since late March in Kyoto, Nara, and Wakayama. Moreover, in Osaka, the infection is spreading in cities other than Osaka City, and the number of new cases of infection is approximately 47. Particularly in Osaka and Hyogo, the overall use rate of beds and use rate of beds by patients in severe conditions are rapidly increasing with the upsurge in number of new cases of infection, putting the medical care provision systems under very severe pressure. In Aichi, the number of cases of infection has increased since late March. The figure remains stable in Fukuoka.
  3. (3) Areas other than those listed above The infection had rapidly spread in Miyagi and Yamagata, however, the number of new cases of infection began to decrease at the end of March to approximately 36 and 15, respectively. Cases are mainly in persons aged under 50; the number of inpatients is increasing in Miyagi. The infection has also rapidly spread since late March in Okinawa. The number of new cases of infection is approximately 46. While the proportion of infected persons in their 20s to 50s is large, the number of inpatients has increased. The number of infections due to clusters, etc. rapidly increased in some other regions. An increasing trend has been observed in Ehime, and then Tokushima and Kagawa in the Shikoku area.

Analysis of infection status

  • There is still concern that the infection may spread further in the Kansai area. The number of cases of infection is increasing not only in Osaka and Hyogo, but also in the surrounding areas. Attention should be paid to the rapid increase in the number of cases of infection with mutant strains in the surrounding areas as well. The flow of people is decreasing in Osaka, however, it will take a certain period of time to see a decrease in the number of new cases of infection. There is also a concern about the continued spread of infection and increase in the number of inpatients. There is a great need to be more vigilant about the situations while monitoring the conditions of medical care provision systems.
  • The number of cases of infection is slightly decreasing in Tokyo and its 3 neighboring prefectures. In Tokyo, the nighttime population rapidly increased after the Declaration of a State of emergency was lifted. The infection has spread in persons in their 20s and 30s despite the recent decrease in figures. Looking at the recent spread of infection in Osaka, Hyogo and Miyagi, etc., the flow of people is increasing after lifting of requests for shortening of business hours in accordance with the measures under the Declaration of a State of Emergency, and the spread of infection has occurred at around 3 weeks after lifting the Declaration. There is concern that the spread of infection may continue or spike in metropolitan areas including Tokyo. The proportion of mutant strains (VOC) detected by screening tests is also increasing. In Miyagi and Yamagata, the flow of people decreased and the number of cases of infection began to decrease after the original measures of the prefectures were implemented. The government of Okinawa started its own measures. Although the increase in the number of cases of infection slowed down, the increasing trend continued, and the infection spread mainly in young people. The progress in these trends should be monitored from now on.
  • The places of clusters are diverse, including medical institutions, welfare facilities, schools, workplaces, restaurants, scenes of eating and drinking, and sports. Clusters have occurred in restaurants and karaoke bars during the day. Such clusters should be carefully monitored.
  • There is concern in some regions that the proportion of mutant strains (VOC) will continue to grow and there will be further rapid spread of infection and high infectivity of these strains compared to the existing ones.

Measures to be taken

  • In Miyagi, Osaka, and Hyogo, which were designated as areas to be subject to the priority measures such as prevention of the spread of infection in view of the rapid spread of infection, necessary measures should be steadily taken including thorough patrols and requests for restaurants including the shortening of business hours to 20:00, which should be implemented in application of this measure, as well as priority testing, securing medical care provision systems, and requesting restaurants to refrain from using karaoke equipment. Particularly in Osaka and Hyogo, reported cases of mutant strains (VOC) increased in many cases of infection reported. The medical care provision systems have already been under severe pressure, and securing beds for patients in severe conditions, which are expected to increase, should be prioritized. The infection is rapidly spreading beyond Osaka City to neighboring Kyoto, Nara, and Wakayama. Prompt and appropriate measures are required to prevent spread of mutant strains associated with movements of people to other regions, including non-essential and non-urgent outings and movements. It is also required to conduct analyses of the causes of the spread of infection and take measures against the spread of infection based on these analyses.
  • In other regions where the number of cases of infection is increasing, it is necessary to promptly make efforts to control the infection in view of the infection status. It is required to take measures such as requests to shorten the business hours of restaurants and patrols, requests asking people to refrain from going out, improvements for systems to conduct tests without delay, and prompt surveys of close contacts and the sources of infection. Based on such measures, it is necessary to secure medical care provision systems and public health systems to respond to further spread of infection, in addition to support by the national government. Immediate action should be taken.
  • For the Tokyo metropolitan area, the number of cases of infection is increasing particularly in Tokyo, and the nighttime population and proportion of mutant strains detected are likely to induce significant concern about the future course of the disease. As with Osaka and Hyogo, the spread of infection may occur after lifting the Declaration of a State of Emergency. It is necessary to promptly organize testing/consultation systems assuming re-spread of infection and medical care provision systems including recuperation at accommodation facilities and at home, as well as sufficient and timely measures responding to the infection status.
  • The number of cases of infection has rapidly increased in areas outside the metropolitan area where no large-scale spread of infection had previously occurred. Assuming that an actual spread of infection will also occur in regions with no previous large-scale spread of infection, it is necessary to check again whether necessary preparations have been made, such as securing consultation/testing systems and beds/accommodation facilities for recuperation, securing systems for arrangements including recuperation at home and systems for support from the entire government agency, as well as collaborative systems between prefectures and cities with health centers in case of a new spread of infection.
  • There is already a new sign of a spread of infection with movements of people associated with the change to a new fiscal year. In order to prevent further spread of infection, it is necessary to ask people to refrain from opportunities of people getting together such as 3Cs (closed spaces, crowded places, and close contact settings), and parties associated with various events for the beginning of new fiscal year. Furthermore, for the prevention of infection, people should be appropriately informed of the risk of infection in situations where the elderly will get together such as daytime karaoke and product sales with customer service, eating and drinking together for a long time during the day, and actual situations of clusters. In addition, it is necessary to urge patients with symptoms to undergo the test followed by rapid conduct of the test.
  • Prompt actions for mutant strains with mutation in N501Y (VOC) are required based on evaluations/analyses of epidemiological information on the regional status of infection, infectivity, and pathogenicity considering the recent increase in the number of cases of infection. Particular discussion should be promptly made about actions in medical care provision systems and public health systems, including allocation of private rooms for patients infected with mutant strains and revision in the discharge criteria.

Figures (Number of new infections reported etc.) (PDF)

Copyright 1998 National Institute of Infectious Diseases, Japan

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