Influenza cases in Japan below 0.5% of the average in the first 15 weeks of the 2020-21 season

Data on Japan

Society Health

In the first 15 weeks of the 2020-21 winter season, which began in September, only 383 cases of influenza were recorded.

Every year, the Ministry of Health, Labor and Social Welfare publishes weekly data on flu cases from September to May next year. From the 36th week of 2020, in the period of 15 weeks, which extends from August 31 to December 13, only 383 cases were recorded across the country. The average for the same period in the last five years is about 90,000, or more than 200 times more than in the 2020-21 season.

There are significant differences in the number of cases, because the occurrence of flu epidemics varies from year to year. In 2019, the number already exceeded 3,000 when the data for the first week were compiled, and it increased sharply compared to the 45th week. On the other hand, in 2015, the number of cases increased above 1,000 in week 49, but that was still more than for 2020 in the same period.

MHLW data show that the most recent onset of the influenza epidemic was in the third week of the following year (seasons 2004–05 and 2006–07). This means that there is still a possibility that the number of flu cases will increase sharply, but the number of cases has been noticeably low so far. It is also possible that the measures taken since spring against COVID-19 have played a role in influenza prevention.

(Originally published in Japanese on November 19, 2020 and updated on December 18, 2020. Photo of the inscription: © Ushico / Pixta.)

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