68th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (January 20, 2022). Material 1
Evaluation of the latest infection status, etc.
Infection status
- The number of new cases of infection (by date of report) nationwide was approximately 147 per 100,000 in the last week, and the ratio of the number for this week to last week continued to increase rapidly, to 3.6. The number of newly infected people is increasing mainly among people in their 20s. In addition to Okinawa, Yamaguchi, and Hiroshima, where priority measures to prevent the spread of disease are being applied, the number of new cases of infection continues to increase rapidly, not only in urban areas such as in the Kanto and Kansai regions (e.g., Tokyo and Osaka), but also in other regions. With the rapid increase in the number of new cases of infection nationwide, the number of patients receiving treatment has surged, and the number of severe patients is also on the rise.
- So-called community-acquired infections of the Omicron variant have expanded, and in many regions, replacement of the epidemic strain by the Omicron variant is progressing rapidly, although the Delta variant continues to be detected
Effective reproduction number: On a national basis, the most recent number is above 1 at 1.43 (as of January 3). The figure is 1.45 in the Tokyo metropolitan area and 1.42 in the Kansai area.
Local trends
* The value for new cases of infection is the number of people per 100,000 among the total number for the latest week, based on reporting dates.
- Area subject to priority measures
The number of new cases of infection in Okinawa is 1.1 this week compared to last week, but it must be noted that the number reported may not reflect the actual situation. Furthermore, at about 673 it was the highest in Japan. Most are in their 20s or younger, but those in their teens or younger and those in their 60s or older are increasing. The use rate of beds is slightly less than 60%, and the use rate of beds for severe patients is slightly more than 60%. In Yamaguchi, the number of new cases of infection is approximately 130, and the ratio of this week to last week is 1.6. The use rate of beds is slightly more than 40%. In Hiroshima, the number of new cases of infection is approximately 257, and the ratio of this week to last week is 1.9. The use rate of beds is slightly more than 40%.
- Hokkaido
The number of new cases of infection is increasing rapidly, and has reached approximately 90 (approximately 120 in Sapporo City), with a ratio of this week to last week of 5.6. The infected individuals are mainly in their 20s or younger. The use rate of beds is slightly more than 10%.
- North Kanto
The number of new cases of infection has continued to increase in Ibaraki, Tochigi, and Gunma, reaching approximately 66, 84, and 110, respectively. In each of these prefectures, the ratio of new cases for this week to last week increased rapidly, to above 2. The use rate of beds is slightly more than 20% in Tochigi and slightly less than 40% in Gunma.
- Tokyo metropolitan area(Tokyo and 3 neighboring prefectures)
In Tokyo, the number of new cases of infection has increased rapidly to approximately 229, with a ratio of this week to last week of 4.0. The infected individuals are mainly in their 20s or younger. The use rate of beds is slightly more than 20%, and the use rate of beds for severe patients is slightly less than 20%. Also in Saitama, Chiba and Kanagawa, the number of new cases of infection continued to increase, reaching approximately 129, 123, and 124, respectively. In each of these prefectures, the ratio of new cases for this week to last week increased rapidly, to above 2. The use rate of beds is approximately 30% in Saitama, slightly more than 10% in Chiba and slightly less than 20% in Kanagawa.
- Chukyo/Tokai
In Aichi, the number of new cases of infection continued to increase rapidly to approximately 148, with a ratio of this week to last week of 4.8. The infected individuals are mainly in their 20s or younger. The use rate of beds is slightly more than 10%. In Gifu, the number of new cases of infection continued to increase rapidly to approximately 97, with a ratio of this week to last week of 4.2. In Shizuoka and Mie, the number of new cases of infection has increased to approximately 103 and 85, respectively. In each of these prefectures, the ratio of new cases for this week to last week increased rapidly, to above 2. The use rate of beds is slightly less than 30% in Gifu and slightly more than 20% in Mie.
- Kansai area
In Osaka, the number of new cases of infection continued to increase rapidly to approximately 303, with a ratio of this week to last week of 4.6. The infected individuals are mainly in their 20s or younger. The use rate of beds is slightly less than 30%. In Shiga, Kyoto, Hyogo, Nara, and Wakayama, the number of new cases of infection continued to increase, reaching approximately 149, 217, 169, 125, and 126, respectively. In each of these prefectures, the ratio of new cases for this week to last week increased rapidly, to above 2. The use rate of beds is approximately 50% in Shiga, approximately 30% in Kyoto, slightly less than 40% in Nara, slightly more than 30% in Hyogo, and slightly more than 80% in Wakayama.
- Kyushu
In Fukuoka, the number of new cases of infection continued to increase rapidly to approximately 163, with a ratio of this week to last week of 5.9. The infected individuals are mainly in their 20s or younger. The use rate of beds is approximately 10%. In Saga, Nagasaki, Kumamoto, Oita, Miyazaki, and Kagoshima, the number of new cases of infection continued to increase, reaching approximately 140, 120, 185, 88, 89, and 75, respectively. In most areas, the ratio of new cases for this week to last week increased rapidly, to more than 2. The use rate of beds is slightly less than 30% in Saga, slightly more than 20% in Nagasaki, Oita, and Kagoshima, approximately 30% in Kumamoto, and slightly less than 20% in Miyazaki.
- Area other than the above
Aomori, Miyagi, Akita, Yamagata, Niigata, Ishikawa, Fukui, Yamanashi, Nagano, Tottori, Shimane, Okayama, Tokushima, Kagawa, Ehime, and Kochi were approximately 76, 30, 25, 26, 87, 57, 59, 94, 88, 63, 117, 95, 32, 61, 100, and 38, respectively. The use rate of beds is slightly more than 20% in Niigata, Kagawa, Ehime, and Kochi, slightly more than 30% in Yamagata and Yamanashi, slightly less than 30% in Nagano, slightly more than 30% in Tottori and Shimane, and approximately 20% in Tokushima.
Future outlook and measures to be taken
- The number of newly infected people nationwide is rapidly increasing with replacement by the Omicron variant. In addition to the 3 prefectures that have already been designated as areas to priority measures, priority measures will be newly applied to Tokyo and 12 prefectures from January 21. The rapid increase in the number of infected people this time was considered to have been largely affected by the increase in the opportunities for contact due to year-end parties, Christmas, New Year holidays, and long weekend in January. However, because of the possibility that rapid expansion of infection will continue nationwide based on the characteristics of the Omicron variant, the current rate of increase in the number of infected people, and the rate of positive PCR tests, early measures are required.
- Although the Delta variant is being replaced by the Omicron variant, individuals infected with the Delta variant are also detected. Infection with the Delta variant is more likely to become severe, and in fact severe cases have occurred. The nighttime population tends to increase, especially in urban areas. If the current rapid spread of infection centered on young people continues, there is a possibility that the medical care provision system for mild and moderate cases will rapidly become strained, including the response to a rapid increase in health observers and home care recipients. In addition, the spread of infection in the elderly may lead to increase in the number of severely ill patients. Attention should also be given to the occurrence of cases that are positive for the novel coronavirus among hospitalized patients in ICU and ward settings in general medical care, and increases in the number of infected patients requiring hospitalization, as the underlying disease worsens due to infection. Therefore, the spread of infection must be controlled as soon as possible.
- Findings on the characteristics of the Omicron variant
- [Infectivity/transmissibility]
It has been confirmed that compared to the Delta variant, the generation time has shortened to approximately 2 days (approximately 5 days for Delta). The doubling time and incubation period have also shortened, the risk of re-infection and secondary infection after infection has increased, and the speed of infection spread is very fast.
- [Place/route of infection]
In Japan, many infections occur from the same opportunities as before (indoors with insufficient ventilation, opportunities of eating and drinking, etc.), and the routes of infection are considered to be via droplets, aerosol inhalation, contact infection, etc. as before.
- [Severity]
It has been suggested that infection with the Omicron variant may have a relatively lower risk of hospitalization and aggravation than the Delta variant, but in some areas, hospitalizations due to the Omicron variant infection have already increased.
- [Duration of viral shedding]
Viral shedding in patients infected with the Omicron variant decreased over time regardless of vaccination status, showing that the possibility of viral shedding is low from 10days after onset or diagnosis, as with the conventional strain.
- [Vaccine effect]
The preventive effect against infection with the Omicron variant by primary immunization is markedly reduced, but the preventive effect on aggravation is maintained at a certain level. It has also been reported that booster shot improves the infection-preventing effect and hospitalization-preventing effect for infection by the Omicron variant.
- [Infectivity/transmissibility]
- Efforts based on the spread of infection by Omicron variant
- [Monitoring system in Japan]
While the spread of infection with the Omicron variant is progressing nationwide, it is necessary to continue the surveillance system according to the local infection status, including the situation of replacement with the Omicron variant. In regions experiencing a rapid spread of infection, it is necessary to prioritize tests and active epidemiological surveys based on the findings obtained thus far, and to change the treatment systems. It is also necessary to confirm the Delta variant in severe cases and cluster cases. Monitoring must be continued by a certain number of genome analyses.
- [Measures taken by local governments]
Based on the infection status of the region and forecasts of the numbers of infected cases and severe cases, local governments must work flexibly to secure the required number of beds and healthcare professionals, secure the functions of public health centers, which are indispensable for local communities, along with support for strengthening the healthcare center system, and establish home-visit and online medical care systems for home care recipients. At that time, it is necessary to secure a system for prompt administration of oral therapeutic drugs and neutralizing antibody drugs for patients at risk of developing severe disease, such as elderly patients and patients with underlying diseases.
- [Implementation of tests]
In regions where the infection is spreading, it is necessary to actively perform tests for employees at facilities for the elderly, based on the Basic Policies for Novel Coronavirus Disease Control. In addition, it has become possible to receive free tests for those who are worried about infection and wish to receive such tests. However, in regions where the infection is spreading rapidly, attention needs to be paid to the rapid increase in the demand for these tests as well as the ability of the tests, and a system to ensure prioritized testing needs to be secured.
- [Reinforcement of information provision to non-vaccinated and booster vaccinated people]
It is particularly important to promote the vaccination of unvaccinated people, and local governments must enhance the communication of information to those who have not yet been vaccinated. At the same time, booster vaccinations, which have already been started, must also be implemented steadily. In doing so, it is necessary to smoothly carry out an accelerated vaccination of healthcare professionals and the elderly.
- [Border control measures]
It is necessary to regard those who are positive in the immigration inspection as positive for the Omicron variant, and to continue whole-genome analysis for positives, in order to monitor strains circulating overseas. The waiting period after entering Japan has been shortened to 10 days, but it is necessary to continue to verify future border control measures, including the waiting period, while taking into account the prevalence of the Omicron variant in Japan and overseas.
- [Monitoring system in Japan]
- Immediate review of the business continuity plan of each business in the region is necessary
- Due to the rapid spread of infection in the region, infections among employees and their families, or withdrawal from the workplace due to close contact is highly likely, especially at medical institutions and nursing welfare facilities. Since the same thing can happen in other workplaces needed for social maintenance, their business continuity plans must urgently be inspected. In addition, based on the newly obtained scientific findings on the Omicron variant, it is possible to shorten the period of health observation for healthcare professionals and close contacts, and to further shorten the period by combining tests for people needed for the maintenance of social functions, at the discretion of the region. The period of recuperation for unvaccinated people was determined to be the same as that for vaccinated individuals. The period of health observation and the period of recuperation must be continuously reviewed appropriately.
- It is essential to share the current infection situation widely with citizens and businesses, and cooperate to prevent the spread of infection.
- Governments, businesses, and citizens need to act with the awareness that infection with the Omicron variant is spreading not only areas in priority measures, but throughout the country.
- Basic anti-infection measures are also important for the Omicron variant, and it is necessary to continue to ensure proper wearing of masks, hand washing, ventilation, etc., including among vaccinated people. Although the risk of infection is highest when the three Cs (crowded places, closed spaces, and close contact) overlap, even one C should be avoided as much as possible, due to the high transmissibility of the Omicron variant.
- Crowded places and places with a high risk of infection must be avoided when going out. When it is necessary to use restaurants, it is necessary to select a third party-certified restaurant that implements infection control measures such as good ventilation, with as few people as possible, to avoid loud noises and long hours, and to wear a mask when not eating or drinking.
- In order to protect the lives of both yourself and your family, and at the same time prevent the spread of infection by the Omicron variant, it is necessary to refrain from going out if you feel a little unwell, such as a mild fever or fatigue, and to be examined and receive tests according to government guidelines.
Figures (Number of new infections reported etc.) (PDF)