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) 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) 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) 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) 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) 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) 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) 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) 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.