国立感染症研究所

43th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (July 14, 2021).  Material 1

 

Evaluation of the latest infection status, etc.

Infection status

  • The number of new cases of infection nationwide is increasing, with approximately 12 per 100,000 population for the latest week of reporting dates. The ratio of this week to last week has been 1 or higher for two weeks. Spread of infection is remarkable especially in the metropolitan area, mainly in Tokyo, and the effects on the surrounding regions and across the country are of concern. The infection has obviously spread in July also in the Kansai area, and the number of new cases of infection shows an increasing tendency in other regions. On the other hand, the decreasing trend in the number of severe patients and deaths is continuing. In addition, the proportion of elderly patients among infected patients continues to decrease.

    The nationwide effective reproduction number is above 1, 1.05 most recently (as of June 27). In the metropolitan area, the figure is 1.10 in the Tokyo metropolitan area and 1.13 in the Kansai area.

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

    In Tokyo, the number of new cases of infection has continued to increase, reaching approximately 40. The ratio of this week to last week is 1.32. The cases of infection are mainly in those in their 20s to 40s. The persons with infection aged 65 years or older increased but the proportion of them decreased to approximately 4%. The number of inpatients is increasing mainly in those in their 50s or younger. The severe patients are increasing, and has leveled off most recently. The number of new cases of infection has increased in Saitama, Chiba, and Kanagawa, reaching approximately 14, 19, and 24, respectively. The ratio of this week to last week has been 1 or higher for two weeks or more. The nighttime population is slowly decreasing in Tokyo. On the other hand, the nighttime and daytime populations increased in Saitama, Chiba and Kanagawa. The figure rapidly increased in the first week after lifting the Declaration of Emergency State in Tokyo, and it is of great concern that the infection may spread for the time being mainly in Tokyo. The number of new cases of infection in the Tokyo metropolitan area accounts for approximately two-thirds of the entire country. It is necessary to thoroughly take measures to prevent the spread of infection to surrounding regions and across the country.

  2. Okinawa

    The number of new cases of infection has continued to decrease to approximately 23. The cases are mainly in persons in their 20s to 30s, but the proportion of persons with infection aged 60s or older is just below 20%. With decreasing number of new cases of infection, the use rate of beds decreased, patients staying at home and arrangements for hospitalization are in a decreasing trend. The conditions of beds for severe patients are still under severe pressure. The nighttime population stopped increasing and has leveled off. Attention should be paid as to whether the number of new cases of infection is decreasing.

  3. Kansai area

    The number of new cases of infection is in an increasing trend in Osaka, reaching approximately 13. The use rate of beds and the use rate of beds for severe patients remain below 20%. The nighttime population turned to increase again and reached a level as high as that in mid-March, raising concern about the continued spread of infection.
    There is an upward movement in the number of new cases of infection also in Kyoto and Hyogo with a figure of approximately 6 in each.

  4. Other than the above

    The number of new cases of infection appears to going upward in Hokkaido, Aichi, and Fukuoka, where the priority measures such as for prevention of the spread of disease were lifted, reaching approximately 8, 6, and 6, respectively. The nighttime population also increased in Hokkaido and Aichi, and there is concern about rebound.
    The number of new cases of infection increased in other regions, and attention needs to be paid for such prefectures as Iwate, Miyagi, Fukushima, Ibaraki and Ishikawa.

Analysis of mutant strains

  • Clusters due to the B.1.617.2 lineage variant (delta variant) have been reported and community-acquired infections have also been observed. The positive rate in the screening tests (mechanical estimation) has increased to approximately 11% nationwide. The delta variant is suggested to be more infectious than the B.1.1.7 lineage variant (alpha variant). It is expected 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

  • A four-day holiday and summer vacation are coming up providing opportunities to meet people whom one does not usually meet, increasing the risk of spread of infection. It is necessary to minimize such behaviors. Also, in order to prevent the spread of infection in the Tokyo metropolitan area to other regions, caution is required in homecoming visits and movements across prefectural borders. It is necessary to ensure delivery of such messages to citizens.
  • Tokyo was designated as an area under emergency measures on July 8, and the measures for Saitama, Chiba, Kanagawa, Osaka and Okinawa were extended. It is required to curb the spread of infection early by thoroughly implementing the basic policy revised on July 8. It has been suggested that multiple times of participation in eating and drinking in large gatherings or for long hours, and banquets serving alcohol increase the risk of infection. The measures for scenes of eating and drinking including drinking at home and in the streets should be thoroughly taken, considering the fact that the infection in such scenes causes infection at their home and companies. Thorough implementation of teleworking and health monitoring/measures against infection is required in workplaces. It is important to refrain from non-essential and non-urgent outing and movements, and communicate such efforts.
  • In Tokyo, the number of inpatients is in an increasing trend, and the number of severe patients in their 40s and 50s has reached the same level as that observed in the previous phase of infection spread. It is expected to take about two weeks to benefit from reinforcement of measures, and the spread of infection will continue for a while. Therefore, it is required to secure/cooperate with medical provision systems and public health systems according to such circumstances.
  • The number of new cases of infection turned to increase also in other regions. With vaccination for the elderly moving forward, the numbers of severe patients and deaths are in a decreasing trend. Effects of this fact on the evaluation of the condition of medical care provision systems should be examined. 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.
  • While clusters at medical institutions and facilities for the elderly are decreasing, they have occurred at workplaces and schools/educational facilities. It is required to take measures, such as thorough preventive measures against infection in such places.
  • While vaccination mainly for the elderly is moving forward, the proportion of the elderly in the new cases of infection has become the lowest since last Autumn, indicating the effect of vaccines. It is necessary to steadily promote vaccination. Strategic vaccination is important, focusing on places with a high risk of infection or the routes of infection in order to control the epidemic. To achieve this, particularly in young people, concern and anxiety need to be wiped out.
  • In addition to prevention of the onset of disease and aggravation, there have been reports on vaccination suggesting its preventive effect on infection. It is necessary to properly analyze and evaluate the effects associated with the progress of vaccination and to discuss appropriate ways of preventing infection after sufficient progress in vaccination.
  • 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 in line with local statuses of infection.

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

Copyright 1998 National Institute of Infectious Diseases, Japan

Top Desktop version