国立感染症研究所

41th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (June 30, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • Although the number of new cases of infection nationwide continued to decline on the basis of reporting dates, it has levelled off and started to slightly increase to approximately 8 per 100,000 population for the latest week. In Tokyo and the metropolitan area, the number of new cases of infection turned upward and re-expansion of infection is of great concern. On the other hand, along with the decrease in the number of new cases of infection, the numbers of severe patients and deaths have decreased. In addition, the proportion of elderly patients among infected patients continues to decrease.

    It remains below 1 at 0.87 (as of June 13) nationwide, but it is on an upward trend. In the metropolitan area, the number is 1.00.

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. Tokyo metropolitan area (Tokyo and its 3 neighboring prefectures)

    In Tokyo, the number of new cases of infection turned upward to approximately 25 and the ratio of this week to last week has increased to 1.22. The new cases are those in their 10s to 30s, mainly in their 20s. Clusters in schools and educational facilities have occasionally occurred. The proportion of patients aged 65 years or older is small at approximately 5%. The number of severe patients is tending to decrease. In Saitama, the number of new cases of infection has increased to approximately 9 and the ratio of this week to last week is 1.24. In Chiba and Kanagawa, the number has levelled off and started to slightly increase to approximately 13 and 15, respectively. The ratio of this week to last week exceeded 1 most recently. In the entire metropolitan area, new cases of infection are mainly those in their 20s. In Tokyo, the nighttime population has increased by 18% in the first week since the declaration of a state of emergency was lifted. The late-night population has also surged. In Saitama, Chiba, and Kanagawa, the de facto population has notably increased in the late afternoon when alcohol can be served. The nighttime population has also increased. Particularly in Tokyo, there is strong concern about a spread of infection in future. Measures should be thoroughly implemented to avoid a spread of infection to surrounding areas and the whole country       

  2. Okinawa

    The number of new cases of infection remains high at approximately 33, but continues to decrease. New cases are mainly in those in their 20s to 30s. The use rate of beds remains high, and the hospitalization rate is on the upward trend 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. The nighttime population continues to increase and the number of new cases of infection remains high. But the speed of decrease has slowed. Attention should be paid to future trends.

  3. Kansai area

    In Osaka, the number of new cases of infection has stopped decreasing and remains flat at approximately 8. In Kyoto and Hyogo, the number has continued to decrease to approximately 4 and 3, respectively. The numbers of inpatients and severe patients are also tending to decrease, showing improvement. In Osaka, both nighttime and daytime populations have rapidly increased in the first week since the declaration of a state of emergency was lifted. The late-night population has also surged. In Hyogo and Kyoto, the nighttime population has increased. Particularly in Osaka, if the de facto population continues to increase, there is strong concern about a rebound and caution is required.

  4. Aichi

    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 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 number of new cases of infection is expected to decrease, but the de facto population has notably increased in the late afternoon when alcohol can be served. The nighttime population has also increased and careful monitoring is needed as to whether the decreasing trend of new cases of infection continues.

  5. Hokkaido

    The number of new cases of infection has continued to decrease to approximately 4. In Sapporo City, the center of infection spread, the number has decreased to approximately 9. The number of new cases of infection is expected to decrease in future, but the nighttime population has rapidly increased in the first week since the declaration of a state of emergency was lifted. Attention should be paid to whether the downward trend in the number of new infections continues.

  6. Fukuoka

    The number of new cases of infection has continued to decrease to approximately 4. 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 number of new cases of infection is expected to decrease, but the de facto population has notably increased in the late afternoon when alcohol can be served. The nighttime population has also increased and careful monitoring is needed as to whether the decreasing trend of new cases of infection continues.

  7. Other than the above

    In Fukui, the number of new cases of infection is approximately 15. Although the number has recently turned downward, it has increased mainly among people involved in restaurants and therefore attention should be paid.

Analysis of mutant strains

  • Clusters due to the B.1.617.2 lineage variant (delta variant) have been reported and community-acquired infections are also observed. The positive rate in the screening tests (mechanical estimation) is still at a low level of approximately 5% nationwide, but it has increased. The delta variant is suggested to be more infectious than the B.1.1.7 lineage variant (alpha variant). It is indicated that the delta variant will continue to replace the existing strains, and therefore it is necessary to pay close attention to it.
  • Study results showing vaccine efficacy against variants after the second vaccination have also been reported. It is necessary to continue analysis.

Future outlook and measures to be taken

  • In Tokyo, the number of new cases of infection has turned upward. There is strong concern about further spread of infection in Tokyo and the metropolitan area and its impact on various areas. Thorough implementation of measures is required particularly in Tokyo, given the experiences where the flow of people increased and rebounded immediately after the measures were lifted as well as the possibility that infection will spread faster than before due to the delta variant. There are some restaurants that serve alcohol until late at night and some people without a mask during a meal. It is important to strengthen measures in situations of eating and drinking. As for other areas, the ratio of this week to last week has increased in some regions and the measures need to be thoroughly ensured.
  • In many of regions where emergency measures and priority measures, such as for prevention of the spread of disease are applied as well as regions where these measures were lifted, the flow of people has sharply increased. Therefore, the decrease in the number of new cases of infection has been slowed or halted, or shifted from plateau to increase in some areas. Vaccination in the elderly has been promoted and the numbers of severe patients and deaths continue to decline. However, if the number of infected patients sharply increases, beds for inpatients are estimated to become insufficient ahead of shortage of beds for severe patients. Flexible interventions will be required to curb rapid expansion, if there is a sign of a spread of infection.
  • According to the recently compiled “Measures after June 21, 2021,” vaccinations are needed to be steadily promoted, including workplace vaccination, and necessary efforts should be steadily continued to curb the spread of infection.
  • Vaccinations have been promoted mainly in the elderly. There are reports suggesting the effect of infection prevention in addition to the prevention of onset and aggravation. It is necessary to properly assess the impacts of vaccination on the situation of infection, changes in the number of inpatients, the situation of arranging hospitalization, the rate of hospitalization, and the number of severe cases, as well as the associated burden on the medical care provision systems. In addition to promoting vaccination steadily in future, strategic vaccination is important focusing on places with a high risk of infection or the routes of infection in order to control the epidemic. Particularly in young people, concern and anxiety need to be wiped out.
  • Regarding the delta variant, about which there is much concern surrounding its replacement with existing strains, it is particularly essential to suppress the spread of infection as much as possible by following the measures: strengthening of nationwide monitoring by screening of the L452R variant, as well as active epidemiological surveys and thorough tests for variants. It is also necessary to continue taking prompt border control measures.

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

Copyright 1998 National Institute of Infectious Diseases, Japan

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