28th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (March 31, 2021). Material 2
Evaluation of the latest infection status, etc.
Infection status
- The number of new cases of infection nationwide has continued to increase based on the reporting date since early March, and the number in the most recent week is approximately 10 per 100,000 population. It is necessary to turn the trend downward again.
Effective reproduction number: The effective reproduction number had fallen below 1 since early January nationwide, has exceeded 1 since late February, and is 1.06 recently (as of March 14). The levels remain below 1 in Tokyo and its 3 neighboring prefectures, as well as Aichi/Gifu and Fukuoka at the same time point, but it has been above 1 in Osaka/Hyogo/Kyoto.
- There is a high risk of more rapid spread of the mutant strains with the N501Y mutation (VOC) detected in the UK and South Africa, etc. which are concerned to cause considerable effects. An increasing trend of infections with mutant strains has continued and clusters have continued to occur while active epidemiological investigations are being conducted by local governments.
[Local trends]
* The value of new cases of infections 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 (Tokyo and its 3 neighboring prefectures) One week has passed since the Declaration of a State of Emergency was lifted. In Tokyo, the number of new cases of infection has continued to increase since mid-March to approximately 18 in Tokyo. In Kanagawa, Saitama, and Chiba, the number of new cases of infection remained stable, i.e., approximately 8, 11, and 12, respectively. The burden on medical care provision systems has decreased; in Tokyo, the number of inpatients, which had decreased since mid-March, began to increase.
- (2) Kansai area/Chukyo area/Kyushu: Approximately four weeks have passed since the Declaration of a State of Emergency was lifted. With the increase in the flow of people, the increasing trend has been more obvious since mid-March in Osaka and Hyogo. Also in Nara and Wakayama, the number of infections has significantly increased since late March. Also in Aichi and Gifu, an increasing trend has been observed from late March. The number of infections remains stable or is in a decreasing trend in Fukuoka. Especially in Osaka, the number of new cases of infection is approximately 25. In addition, reports on mutant strains are increasing in Kansai. The burden on medical care provision systems had decreased, but the use rate of beds is increasing with increases in new cases of infection, especially in Hyogo, where the system is under severe pressure.
- (3) Areas other than those listed above The number of infections has rapidly increased since early March in Miyagi, and mid-March in Yamagata. The number of new cases of infection is approximately 41 and 22, respectively. Mainly occurred in persons aged under 50; the number of inpatients has increased. In Okinawa, the number of infections has increased since early March, and it increased significantly in mid- and late March. The number of new cases of infection is approximately 36. The flow of people is increasing. While the proportion of persons infected with the virus in their 20s and 50s is high, the number of inpatients also increased. In Ehime, the number of new cases of infection has significantly increased since late March due to clusters related to restaurants or night clubs with hospitality services, i.e., approximately 17. And there are other regions where the number of infections has increased due to clusters, etc.
Analysis of infection status
- There is strong concern about the spread of infection in Kansai area. The spread of infection occurred again in Osaka and Hyogo, where the measures under the Declaration of a State of Emergency had been lifted earlier. Especially in Osaka, the nighttime population has continued to increase since lifting the Declaration resulting in increases in infected persons in their 20s and 30s. While many cases of infection are occurring, reports of mutant strains are also increasing, suggesting the possibility of future spread of infection. Thus it is required to prevent mutant strains from migrating into other regions by restricting movements of people as much as possible.
- In the Tokyo metropolitan area, the number of infections is slightly increasing in Tokyo and its 3 neighboring prefectures; in Tokyo, the nighttime population at 20:00 or later had increased since two weeks before lifting the Declaration, and it rapidly increased after lifting the Declaration. The proportion of young persons infected with the virus is large and there is much concern about the future rapid spread of infection. In the Tokyo metropolitan area, the sources of infection and the places where clusters occur are diversified (parties with a large number of people and eating and drinking together during daytime), the number of infections is large and highly anonymous, and therefore the route of infection is often unknown.
- In Miyagi, Yamagata and Okinawa, the infection is spreading mainly in young to middle-aged people. In all of the 3 prefectures, the effective reproduction number remains 1 or higher, and there is concern about the spread of infection in future. Unique measures have been taken by each prefecture, and the flow of people is decreasing in Miyagi. It is necessary to continue to pay attention to future progress.
- There is concern in some regions that the proportion of mutant strains will become higher, and that there will be a more rapid spread of infection and high infectivity of these compared to the existing ones.
Measures to be taken
- Although the Declaration of a State of Emergency was lifted, the infection has spread again in the Kansai metropolitan area and the number of new cases of infection is also increasing in Tokyo. In regions other than those under the measures for the State of Emergency this time, the number of infections is rapidly increasing in Miyagi, Yamagata, and Okinawa. Effective measures to control the infection are required in regions where the number of infections is increasing. It is required to take measures such as requests to shorten the business hours of restaurants and refraining from going out, improvements for systems to conduct tests without delay, and prompt surveys of close contacts and the sources of infection. Based on such measures, it is necessary to secure medical care provision systems and public health systems to respond to further spread of infection, in addition to support by the national government. Adjustments for hospitalization have also been delayed in some regions, and prompt action should be taken.
- Especially in the metropolitan areas, the population is large, and the continued infection has a great impact on the other areas. In Osaka, while many cases of infection are occurring, reports of mutant strains are also increasing, and prompt and appropriate measures are being demanded in cast of the possible spread of infection in the future. In addition, the number of infections is increasing in Tokyo, and there is concern about what will occur. Appropriate measures are required considering the infection status for the Tokyo metropolitan area.
- On the other hand, rapid spread of infection may occur in regions where there has been no large spread of infection so far. Assuming that an actual spread of infection will occur, it is necessary to check again whether necessary preparations have been made, such as securing consultation/testing systems and beds/accommodation facilities for recuperation, securing systems for arrangements including recuperation at home and systems for support from the entire government agency, and collaborative systems between prefectures and cities with health centers in case of a new spread of infection.
- It is often accompanied by movements and training of persons during the period when people join a company or enter a school at the beginning of the fiscal year. In addition, attention should be paid to situations where the elderly will get together, such as daytime karaoke and product sales with customer service, as well as eating and drinking together for a long time during the day. The spread of infection is emerging and people need to be made better aware of this so that they refrain from getting together under circumstances such as 3Cs, as well as parties associated with annual events at the beginning of fiscal year (welcome and farewell parties, cherry-blossom viewing) (especially parties where one comes into contact with those they would not usually meet), including persons who were transferred to another workplace, etc. at the time of change of fiscal year.
- For mutant strains with mutation in N501Y, considering that their effects will be considerably larger, measures to minimize the effects are required. To realize this, the following measures are required in line with the package of measures against mutant strains presented the other day: (1) continuation of strengthening border control measures, (2) prompt reinforcement of the surveillance system of mutant strains in Japan, (3) early detection of persons infected with mutant strains, identification of close contacts and the source of infection through active epidemiological investigations and prompt implementation of preventive measures against infection, (4) assessment and analysis of the epidemiological information on the infectivity and pathogenicity of mutant strains (continuing to understand the present situation of mutant strains with mutations, such as E484K, other than N501Y variants) and proper dissemination of information, (5) promotion of research developments including centralized collection/analyses of samples and clinical information, etc. In addition, discussion should be promptly made about the handling of patients when being hospitalized in relation to mutant strains and actions in medical care provision systems and public health systems, such as the discharge criteria.
- In order to promote such efforts, actions should also be taken to visualize the infection status in prefectures by using Her-Sys, etc. to accurately grasp the infection status in various regions.