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Infection with the new coronavirus mutant strain has been confirmed in airport quarantine and in Japan, and the proportion of the mutant strain is increasing. Mutant strains are also called mutant viruses, and it has been pointed out that changes in the genetic information possessed by conventional strains may increase infectivity and increase pathogenicity, making them more likely to become severe and making vaccines less effective. I am. All infected people are hospitalized, including asymptomatic.

A normal PCR test detects the gene of a protein in the viral genome that is less likely to be mutated. However, the virus infects (invades) the cells in the British type (VOC-202012 / 01 mutant strain), South African type (501Y.V2 mutant strain), and Brazilian type (501Y.V3 mutant strain) where the mutation is contained. It is a gene for a spike protein that sometimes functions and cannot be identified by a normal PCR test. It has been pointed out that the gene "N501Y" is mutated in the British type, South African type, and Brazilian type in common, and it is possible that the infectivity is higher than that of the conventional strain.

The mutant strain PCR test (reagent) determines whether it is a conventional strain or a mutant strain by identifying the N501Y mutant site. This test is conducted mainly by local health research institutes nationwide, and it is said that about 5 to 10% of positive people can carry out this test. The government has announced a policy to raise the PCR test for mutant strains to about 40% at an early stage, but the cooperation of private testing companies is indispensable for that purpose.

Ministry of Health, Labor and Welfare Drawing with reference to the response to the new coronavirus infection (mutant strain)

If the N501Y mutation is positive, the genome will be analyzed and the types of British, South African, and Brazilian types will be determined based on the confirmation of the National Institute of Infectious Diseases. Genome analysis has also been performed on N501Y mutation-negative specimens, and a new E484K mutation that may reduce the effects of immunity and vaccines has been confirmed.

Experts have provided guidelines for private testing companies to allow the government to additionally test mutant strains for specimens that are positive in normal PCR tests, and mutant strains in private testing. He points out that it is important not only to investigate the frequency of detection of mutant strains, but also to take measures to prevent the spread of infection, such as building a system to promptly report positive results to health centers. ..