To what extent has the mutated new coronavirus that spreads overseas such as the United Kingdom been tested in Japan?

It was found that more than 400 people were tested for mutant virus in the week leading up to the end of last month in 1 metropolitan area and 3 prefectures in the metropolitan area where the state of emergency was extended.

This is about 10% of the newly infected people announced during this period.

Experts point out that "the monitoring system such as inspection needs to be further strengthened."

Why is this happening?

Detected from a total of 194 people in 20 prefectures nationwide (excluding airport quarantine)

Mutant viruses that are rampant overseas are considered to be more infectious than before, and are said to have a major impact on the status of infection in Japan in the future.

In Japan, the mutant virus has been detected in a total of 194 people in 20 prefectures nationwide, excluding airport quarantine, by the 5th of this month.

What is the inspection system?

In the first place, what kind of system is used to inspect mutant viruses?

First, the local government extracts some of the positive people of the new corona and, in principle, analyzes them by PCR at the Local Health Research Institute.

When a mutant virus is suspected in a local government test, we send a sample to the National Institute of Infectious Diseases and perform genome analysis to confirm the result.

Approximately 10% of newly infected persons announced in 1 metropolitan area and 3 prefectures

Not all infected people are tested for the mutant virus, and some people are selected by the local government, so it is possible that not all infected people have been found.

This time, NHK investigated how much the mutant virus was tested in Tokyo, Kanagawa, Saitama, and Chiba prefectures where the state of emergency was extended.

As a result, it was found that 418 people were tested for the mutant virus during the week leading up to the 28th of last month in all three prefectures.

This is about 10% of the newly infected persons announced during this period.

However, in reality, the test for mutant virus may be carried out some time after the infection is confirmed, so it is not a number that indicates the test rate during this period.

By prefecture,

▽ Tokyo tested 149 people, and no one was confirmed to have a mutant virus.

▽ Kanagawa has inspected 43 people, and the final result has not been obtained yet.

▽ Saitama examined 44 people, and no one was confirmed to have a mutant virus.

▽ Chiba examined 182 people and found that one of them was infected with the mutant virus.

Local government “In the middle of system development” “Samples cannot be stored / collected”…

The national government requires local governments to extract and examine samples from 5% to 10% of newly infected persons.

Regarding the test for mutant virus, from the local

government, in addition to the fact that the system is still in the process of being prepared, there are cases where the

sample is not stored or collected in the first place, and

▽ the virus is so definitive that it can be tested. The problem is that some samples do not have enough genes.

On the other hand, each region wants to strengthen the testing system for mutant viruses in the future.

In addition, according to the Ministry of Health, Labor and Welfare, the results will be confirmed by the inspections of local governments.

Some local governments where mutant viruses have been confirmed are expanding the test by increasing the rate of sample extraction.

What is the spread of infection in Japan?

The mutated new coronavirus that spreads overseas such as the United Kingdom was first discovered in Japan in December last year, and the infection has gradually spread since then.

A total of 20 prefectures have been confirmed by the 5th of this month.

The first mutant virus was confirmed in Japan on December 25, last year.

It was detected in five people who left the United Kingdom and arrived at Haneda Airport and Kansai Airport.

The next day, the mutant virus was confirmed for the first time in Tokyo except for airport quarantine.

In January of the new year

, in Hyogo prefecture

on the


Shizuoka prefecture on the 18th, and

Saitama prefecture on the 28th, the

mutant virus was confirmed for the first time except for airport quarantine.

At this time, some people had no history of staying abroad, so-called community-acquired infections.

In February, the area expanded further

, with Kanagawa prefecture on the 4th,

Fukushima prefecture, Tochigi prefecture, Gunma prefecture, Ibaraki prefecture, Niigata prefecture, Nagano prefecture on the 9th, and

Yamanashi prefecture on the 12th.

Detection of mutant viruses was first reported in

Shiga prefecture,

Kyoto and Kagoshima prefectures on the 16th,

Okayama prefecture on the 18th, and

Osaka prefecture on the 22nd


In some areas, such as workplaces and nursery schools, clusters due to the mutant virus were thought to have occurred.

Even in

March, the

mutant virus was first confirmed in

Chiba and Gifu prefectures on the 3rd and

in Ishikawa prefecture on the 5th


Confirmed infection of a total of 251 people in Japan

By prefecture,

▽ 40 people in Saitama prefecture ▽

37 people in Hyogo prefecture ▽

31 people in Niigata prefecture

15 people in Kanagawa prefecture

14 people in Tokyo

12 people in Osaka prefecture

9 people in Kyoto prefecture

▽ Shizuoka prefecture 7 people in

Fukushima prefecture ▽ 5 people in

Kagoshima prefecture ▽

4 people in Gifu prefecture

3 people in Gunma prefecture

3 people in

Okayama prefecture

2 people in Yamanashi prefecture

2 people in

Shiga prefecture

▽ 1

person in

Ibaraki prefecture Person

▽ 1 person in Chiba prefecture ▽ 1 person in

Tochigi prefecture ▽ 1 person in

Nagano prefecture

1 person in

Ishikawa prefecture A

mutant virus has been confirmed.

By month,

▽ last December was 3 people


▽ this year

January was 21 people,

▽ February was 134 people, a significant increase.

▽ In March, there are already 36 people by the 5th.

In addition to this, there are 57 airport quarantines, and a total of 251 people have been confirmed to be infected throughout the country.

According to the Ministry of Health, Labor and Welfare, regarding the status of mutant virus infection in Japan, "Multiple clusters have been reported and cases with no connection with overseas have been continuously confirmed, but the situation is not widespread in the region."

Expert "The number of inspections is a little smaller

Professor Atsuro Hamada, Tokyo Medical University (Familiar with overseas infectious diseases)

"The number of tests is about 10% in 1 metropolitan area and 3 prefectures, where the number of infected people is large even in Japan, which is a little small to grasp the infection status of mutant virus. I feel that it is necessary to further strengthen the monitoring system such as inspections in order to grasp the spread of the virus at an early stage and utilize it for countermeasures. "

In addition, if there are cases where the mutant virus cannot be tested because the sample is not stored in the testing institution, it is necessary to take a system to properly collect and store the sample including the private testing institution. ..

Regarding the outlook for the future, "Looking at the situation in the world, mutant viruses are spreading mainly in Europe and the United States, and it is highly possible that this will happen in Japan as well. The situation in the third wave is finally settling down, but the virus is highly infectious. It is necessary to delay the time when the mutant virus spreads as much as possible because if the spread of the virus spreads, medical institutions may become tight again and fall into a serious situation. "

On top of that, he also calls on the general public to "recognize that they are still exposed to the threat of these viruses even if the state of emergency is lifted, and continue to take measures such as refraining from eating."