Japan confirms the first case of nine types of delta variant

According to researchers, the first case in Japan involving a new mutation in the delta variant of the coronavirus, highly contagious, has been confirmed, of which only eight cases have been reported worldwide.

A research team at Tokyo Medical and Dental University, led by Associate Professor Hiroaki Takeuchi, announced Monday in a statement that the first case of this delta variant underlining was confirmed in a COVID-19 patient in the middle of August.

According to the genome analysis, “it is very likely to be the last case mutated nationally,” said the researchers, who added that the patient had no history of travel abroad.

The latest case contains the N501S mutation, which is similar to the alpha variant mutation known as N501Y that was first identified in Britain last year. To date, at least a dozen delta variant submutations have been confirmed worldwide, in countries such as India and Israel, according to media reports.

When a patient is infected with a coronavirus variant that carries the N501Y mutation, he or she has an increased risk of secondary infection as well as developing severe symptoms and dying. Because of the similarities between N501Y and N501S, researchers believe that patients infected with N501S could face a similar prognosis.

More research is needed to confirm the potency of the new mutation compared to the original delta variant, they said.

The mutation was confirmed by analysis of the genome collected from COVID-19 patients treated at Tokyo Medical and Dental University.

The analysis also showed that patients with the delta variant increased rapidly between late June and late July due to community outreach.

Currently, the delta variant is growing dominant in Japan. According to the latest data from the health ministry, 1,046 new cases of the delta variant were found in 17,701 COVID-19 cases selected for screening variant the week from 16 August.

Separately, the researchers also concluded that in July there may have been at least two sublines of the delta variant (AY.4 and B.1.617.2). But now they only detect strain B.1.617.2 of the delta variant.

The first delta variant infection in Japan was found on April 20th. Delta has been ranked as one of the four variants of concern by the World Health Organization and has quickly surpassed other versions in some parts of Japan; they are now estimated to account for 95% of all cases in Tokyo.

With the delta variant representing a growing proportion of cases in Japan, the number of patients aged 19 and under is increasing, a health ministry group on coronavirus said last week, urging schools to take action. suitable to prevent the spread of infections.

U.S. Centers for Disease Control and Prevention believes the delta variant is as transmissible as chickenpox and about twice as contagious as previous variants.

The study was conducted jointly by experts in virology and infectious diseases from the Graduate School of Medical and Dental Sciences affiliated with Tokyo Medical and Dental University, the Laboratory of Genome Analysis of the Intractable Diseases Research Institute and the Hospital Tohoku University.