国立感染症研究所

21th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (January 13, 2021).  Material 5

 

Evaluation of the latest infection status, etc

Infection status

  • There is a growing trend of increasing new cases of infection all over Japan with a rapid increase in new cases of infection in the Tokyo metropolitan area, especially Tokyo, with record numbers of new infections. New cases of infection have also rapidly increased in the Chukyo area, the Kansai area, as well as the Kita-kanto and Kyushu regions from the beginning of the new year.

    Effective reproduction number: On a national basis, it remains above 1 (as of Dec. 27). The average weekly level also exceeds 1 in metropolitan areas such as Tokyo, Osaka and Fukuoka, etc. (as of Dec. 27).

  • The increasing trend in the number of inpatients, the number of severe patients, and the number of deaths is continuing. The number of new cases of infection rapidly increased mainly among young people (in their 30s and younger).
  • The staff in health centers and medical facilities who continue to respond to the infection are already considerably exhausted. In the local governments showing a rapid increase in the number of infections, it becomes increasingly difficult to make adjustments to accommodate hospitalizations, and patients are forced to wait in facilities for the elderly, etc. before they can be hospitalized. In more and more regions, it is becoming difficult to balance treatment for novel coronavirus infection and regular medical care. With the increase in the number of new cases of infection, it is becoming impossible to provide the regular treatment that should have been ongoing in the routine medical setting. The burden of data input, etc. at local governments has also increased.
  • Cases of a new mutant strain that are increasing in the United Kingdom and South Africa have also been detected worldwide. In Japan, these cases have only been detected among patients with a history of overseas travel or contact with such persons. Considering the possibly that these strains may demonstrate higher infectivity than the original strains, there is a risk of more rapid spreading than before if the infection continues to occur in Japan. A new variant with various of the mutations found in these variant strains was detected in persons who returned from Brazil. It is difficult to determine the infectivity and pathogenicity at present.
[Trends in regions where the infection has spread]
  1. (1) Hokkaido
    The number of new infections had been decreasing, but has turned to increase again. Infections are continuing to occur in hospitals and facilities. The mass infections in medical facilities and welfare facilities in Asahikawa City have almost settled down. 
  2. (2) Tokyo metropolitan area
    The number of new cases of infection is continuing to increase, i.e., it has been just below 90 per 100,000 persons for the last week. The medical care provision systems remain under very severe pressure. The emergency response is also affected. Adjustments to accommodate hospitalizations, etc. at health centers are under even more severe pressure. Although the route of infection is unknown in many patients, it is assumed that the infection spreads mainly at the scenes of eating and drinking. The number of new infections is continuing to increase in Saitama, Kanagawa, and Chiba throughout the metropolitan area, and the medical care provision system is under severe pressure. New cases with positive test results also rapidly increased in Tochigi with an increase in Tokyo and the neighboring three prefectures; the number of positive test results exceeded 40 per 100,000 persons for the last week, and the medical care provision systems are under severe pressure.
  3. (3) Kansai area
    The number of new cases of infection had gradually decreased in Osaka, and it rapidly increased after the beginning of the new year, exceeding 40 per 100,000 persons for the last week. At the beginning of the new year, infection among young people in their 30s and younger are notable. The medical care provision system remains under severe pressure. Adjustments to allow hospitalization at health centers are also under increasing pressure. The infection rapidly spread and the number of infections exceeded 30 per 100,000 persons in Hyogo and Kyoto, subjecting the medical care provision systems to severe pressure. The increasing trend in the numbers of new cases of infection is also continuing in Shiga and Nara.
  4. (4) Chukyo area
    The number of new cases of infection had remained high in Aichi, and rapidly increased after the beginning of the new year, i.e., just below 30 per 100,000 persons for the last week. The medical care provision system remains under severe pressure. Adjustments to allow hospitalization at health centers are also under increasing pressure. The number of new cases of infection also rapidly increased in Gifu. The medical care provision systems are under severe pressure.
  5. (5) Kyushu
    The number of new cases of infection rapidly increased in Fukuoka. Over the last week, the number of new cases of infection exceeded 40 per 100,000 persons. The medical care provision systems have been under more severe pressure. The numbers of new cases of infection also increased in Saga, Nagasaki, Kumamoto, and Miyazaki.
  6. (6) Other regions than those mentioned above
    In Miyagi, Ibaraki, Gunma, Yamanashi, Nagano, Shizuoka, Okayama, Hiroshima, and Okinawa too, there is a tendency of newly spreading and re-spreading infection, and many new cases of infection continue to occur; the figure exceeded 15 per 100,000 persons for the last week.

Analysis of infection status

  • As for the spread of infection at the end of last year mainly in metropolitan areas such as Tokyo, it is considered that parties at workplaces and scenes where young people eat and drink were the main causes for spread of the infection, which has led to infections at workplaces and home. There is concern about further spread of the infection to elderly people in the future. On the other hand, one of the causes of the rapid increase in the number of infections nationwide from the beginning of the new year is considered to be homecoming visits and eating and drinking with relatives. This needs to be investigated continuously.
  • This spread of infection in Tokyo affected the neighboring regions; new cases of infection are continuing to increase in the Tokyo metropolitan area including Saitama, Chiba, and Kanagawa since the beginning of the new year, and reached a record high. New cases of infection for the last week in Tokyo accounts for just under 30% of those in Japan, and those in Tokyo and the three neighboring prefectures account for just more than half. These tendencies are also observed in the Kansai area including Kyoto, Osaka and Hyogo, the Chukyo area including Aichi and Gifu, and the Kyushu region including Fukuoka. The numbers of new cases of infection in these prefectures account for just under 80% of those in Japan. The spread of infection in the metropolitan area is considered to be related to recent occurrences of infection in local regions. It is difficult to suppress the infection in local regions unless the infection is immediately suppressed in large cities.

Necessary measures

  • A Declaration of Emergency was issued on January 7 in metropolitan areas including Tokyo. The infection rapidly spread, not only in the Tokyo metropolitan area but also the Kansai and Chukyo areas. Considering the severe circumstances of the medical care provision and public health systems, it is essential to immediately take effective measures to reduce infections in these metropolitan areas to prevent spread of the infection in local regions. The infection has rapidly spread in Tochigi, a prefecture neighboring on the Tokyo metropolitan area, and Fukuoka and it is therefore considered necessary to take appropriate actions.
  • The infection is continuing to spread, and the medical care provision and public health systems are under extremely severe pressure. It is necessary to promptly reduce the number of new cases of infection. The medical care provision system is currently under very severe pressure and this situation is expected to continue. Under these circumstances, it is necessary to secure the necessary systems while utilizing the “medical care provision system package” with expanded measures of support that had been prepared at the end of last year. Cooperation of citizens, in addition to shortening of business hours at restaurants and restrictions on events, is crucial to suppress the spread of infection. It is important to voluntarily refrain from non-essential and non-urgent outings, and from eating and drinking in ways that are likely to cause spreading of the infection, even before 20:00, to prevent infection. It is also important to reduce opportunities of contact by remote working, etc. It is necessary for the national and local governments to deliver messages to achieve these goals with a sense of unity.
  • It is important to analyze and evaluate the effects of emergency measures based on the number of new cases of infection, the effective reproduction number, and the burden on the medical systems, etc., continuously discuss how to take measures based on the above-mentioned analysis and evaluation, while making efforts to prevent a rapid re-increase immediately after lifting the state of emergency.
  • It is also necessary to prevent the spread of infection due to the influx of mutant strains observed in the UK, etc. under the severe infection circumstances in Japan, and to strengthen the entire quarantine system. It is necessary to monitor mutant strains and conduct an active epidemiological survey when an infected person is detected. In consideration of the mutant strains found in persons coming from Brazil too, recommendation of mask wearing, hand washing, and avoidance of the 3 Cs, etc. remain in place as basic preventive measures for individuals.

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

Copyright 1998 National Institute of Infectious Diseases, Japan

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