TOKYO -- Suspected N501Y coronavirus variant cases in the Japanese capital have risen rapidly since the start of April with a record 80 likely infections with the mutation found in screening by the Tokyo Metropolitan Government.
One source in the medical community told the Mainichi Shimbun, "The situation could become similar to Osaka," where numerous variant infections are being confirmed. On April 14, Tokyo Gov. Yuriko Koike indicated that she views the current situation as severe, saying, "Clearly the mutation is spreading fiercely."
On March 29, the metropolitan government announced that it had found eight suspected N501Y cases. With the start of April, this jumped to between 10 and 30 people per day. On April 12, 61 variant cases were found, followed by 80 on April 13, and 72 on April 14.
Breaking down the April 13 infections by age, people in their 20s to 30s comprised 43 cases -- more than half of the total. Additionally, a medical facility confirmed a cluster of 16 people suspected of having the variant, and it appears infections are spreading.
Metro government totals show that as of April 14, 408 people have been confirmed infected with N501Y, based on data from inside the capital and national government announcements. The metro government believes that the rise is partly attributable to increasing the number of private firms helping to test for the variant to three, but also to genuine spread.
The proportion of confirmed N501Y cases identified in the screening was only around 3.1% in the week between March 22 and 28, but by April 5 to 11 this had risen to some 28.4% -- a nine-fold rise in just two weeks.
N501Y has spread in Osaka and Hyogo prefectures, both in western Japan's Kansai region, and appears to be behind the infection spike across the whole area. The metropolitan government is calling for people to refrain from travel between major urban areas where mutant strain infections are spreading. A senior metro government official said, "Osaka is proof that a rise in variant infection cases leads to steep rises in overall infections. We have to stop this soon."
Speakers at a Tokyo Medical Association press conference on April 13 each expressed concern. Association chairperson Haruo Ozaki said, "N501Y is very infectious, and it's being said that young people, who were previously not easily infected, are now contracting the virus. It's important that people of all generations consider getting back to basics on infection prevention."
The association's deputy chairperson Masataka Inokuchi said, "Tokyo's variant infection rate is also rising. There's a significant chance that Osaka is the Tokyo of two to three weeks from now."
(Japanese original by Shinji Kurokawa, Hitomi Saikawa and Asako Takeuchi, Tokyo City News Department)