25th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (February 24, 2021). Material 1
Evaluation of the latest infection status, etc.
Infection status
- The number of new cases of infection in Japan has continued to decrease since the middle of January based on the reporting date (since the beginning of January based on the date of onset), and the number in the most recent week is approximately 7 per 100,000 population. The speed of infection reduction has slowed down since the middle of February and the number of new cases of infection may bottom out, though attention should be paid to recurrences.
Effective reproduction number: The effective reproduction number has fallen below 1 from the beginning of January nationwide and has been 0.78 recently (as of February 8). In Tokyo and its 3 neighboring prefectures, as well as Osaka/Hyogo/Kyoto, Aichi/Gifu, and Fukuoka, where the measures for the state of emergency have been employed, the levels continue to be below 1. (as of February 7)
- The declining trend in the number of inpatients, the number of severe patients, the number of deaths, and the number of patients receiving treatment is continuing. In contrast, since the proportion of new patients aged 60 years or older has exceeded 30%, decreases in the number of severe patients and deaths are expected to take more time than the decrease in the number of new cases of infection and inpatients. The burden on health centers and medical institutions has been reduced with decreases in the number of infections and the number of patients receiving treatment. However, on-site personnel have long been responding to the situation of the disease and the impact on their tasks has not been resolved. The occurrence of clusters in elderly facilities has also continued.
[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) Metropolitan area:
In Tokyo, the number of new cases of infection is continuing to decrease, i.e., approximately 16, however, the speed of infection reduction has slowed down. Admission arrangements by local governments has improved. In Kanagawa, Saitama, and Chiba, the declining trend in the number of new cases of infection is continuing, approximately 9, 12, and 14, respectively, which are lower than the index for stage III, 15. A trend toward increase has been observed over the last few days in Chiba, and attention should be paid to recurrences. In Tokyo, Kanagawa, Saitama and Chiba, the burden has been reduced with decreases in the number of new cases of infection and the number of patients receiving treatment. However, the use rate of beds is still high and the medical care provision systems are under severe pressure. - (2) Kansai Area:
In Osaka, the number of new cases of infection continues to decrease, reaching approximately 7, which is lower than the 15. Clusters have continuously occurred in elderly facilities, etc. In Hyogo and Kyoto, the number of new cases of infection is on a declining trend and has reached approximately 5 and 4, respectively. In both prefectures, the medical care provision systems are under severe pressure, however, the burden has been reduced with decreases in the number of new cases of infection and the number of patients receiving treatment. On the other hand, it should be noted that the declining trend in the number of infections in the elderly is slowing down, but hospitalizations of elderly persons, which put a large burden on clinical sites, are increasing. - (3) Chukyo Area:
In Aichi, the number of new cases of infection continues to decrease, reaching approximately 5, which is lower than the 15. In Gifu, the number of new cases of infection has decreased continuously, reaching approximately 4. In both prefectures, the medical care provision systems are under severe pressure, however, the burden has been reduced with decreases in the number of new cases of infection and the number of patients receiving treatment. On the other hand, it should be noted that the declining trend in the number of infections in the elderly is slowing down, but hospitalizations of elderly persons, which put a large burden on clinical sites, are increasing. - (4) Kyushu Area:
In Fukuoka, the number of new cases of infection continues to decrease, reaching approximately 8, which is lower than the 15. The medical care provision systems are under severe pressure; however, the burden has been reduced with decreases in the number of new cases of infection and the number of patients receiving treatment. - (5) Areas other than those listed above:
The number of new cases of infection is generally continuing to decrease.
[Mutant strain]
- For the new mutant strains that are increasing in the United Kingdom and South Africa, cases possibly due to infections in Japan are continuing to occur. The mutant strains may have higher infectivity than the original strains and thus may have more diffusive effects. While the mutant strains continue to spread across the country, there is a high possibility of more rapid spreading than before. Concerning the UK strains, attention should also be paid to the impact of the mutations on the seriousness of the infection. In addition, mutant strains with the E484K mutation not containing the N501Y mutation, which appeared to have been transmitted from overseas, were detected by genome analysis.
Analysis of infection status
- In 10 prefectures in the regions under the state of emergency measures, the effective reproduction number is below around 0.8 and the number of new cases of infection is decreasing. However, the flow of people during nighttime seems to be increasing again. Measures including shortening of the business hours of restaurants serving alcoholic beverages have been taken so far. The speed of infection reduction has slowed down and a trend toward increase is observed especially in Chiba. Attention should be paid to recurrences. However, the number of patients receiving treatment is decreasing with the decrease in the number of new cases of infection, the use rate of beds is on a general decline, and the burden on medical care provision systems and public health systems have been reduced. These trends should be continued.
- Clusters have occurred mainly in medical institutions/welfare facilities and at home, and they are continuing to occur also at restaurants in some regions. It should be noted that there is a trend of bottoming out in the number of infections in young people.
- Regarding the current decreasing phase in the number of new cases of infection, the decrease in urban areas is more delayed than in the surrounding areas. Efforts to maintain this declining trend are required in the midst of the risk of mutant strains. Mutant strains have also been detected continuously in Japan. It is necessary to detect and contain infection by mutant strains at an early stage.
Measures to be taken
- The declining trend of new cases of infection should be continued, recurrences should be prevented, and the numbers of severe patients and deaths should be surely reduced. In addition, measures should be thoroughly taken from now on to reduce the burden on medical institutions that are engaged in vaccination and to accurately detect mutant strains in local areas.
- Considering the bottoming out of the number of infections, continued burden on medical care provision systems, and the risk of mutant strains, the concern that lifting the Declaration of the State of Emergency may induce recurrences should be noted. Even if the Declaration of the State of Emergency is lifted, efforts to reduce infections when eating and drinking, etc. should be continuously made to achieve Stage II or lower according to the situations of infection in local areas. It is necessary to take measures to detect the source of infection and continue to reduce it, considering that a certain level of infection continued and led to re-expansion after the decrease of infection in the summer of last year. For this purpose, it is required to establish a system that can reinforce active tests and active epidemiological studies again according to the infection risk. It is necessary to take actions in case of future waves of infection based on the assessment of current efforts.
- In order to prevent re-expansion, the actions of people at the milestones are key, such as annual events. In order to avoid dining out in a large group in the future, for the period from the end of the fiscal year to the beginning of the new year, it is necessary to send out an effective message so that people can cooperate to avoid farewell parties, thank-you parties, graduation trips, and cherry-blossom viewing.
- To “protect the elderly,” efforts to prevent the spread of infection are required at welfare facilities where clusters have continued to occur. It is required to steadily conduct the test for the staff of facilities based on the plan and support the measures against infection by dispatch of specialists, etc.
- Vaccination was started first for healthcare professionals. It is necessary to assess and analyze the effects on the situations of infection based on the vaccination.
[Mutant strain]
- As well as strengthening the quarantine system, measures should be taken considering that the effects of the mutant strains will become larger. Early detection of the persons infected with mutant strains, the identification of the sources of infection by active epidemiological surveys, prompt implementation of the measures to prevent the spread of infection, and support for the cases of spread in a wide area are required through strengthening the surveillance system of mutant strains in Japan (cooperation with private test laboratories and universities. The national government should regularly check the number of tests conducted by the local governments). In addition, it is necessary to assess and analyze the epidemiological information on the characteristics of infectivity and pathogenicity. For mutant strains with the E484K mutation not containing the N501Y mutation, it is needed to continue to grasp the actual situation. Reduction in opportunities of contact (avoidance of 3 Cs, especially the 5 situations that increase the risk of infection), wearing of a mask and hand washing, etc. are also recommended as basic preventive measures for individuals. In addition, if symptoms are present, appropriate tests/examinations should be performed. And it is necessary to provide the whole picture of these efforts.