TOKYO: The average number of flu patients per regularly monitored hospital across Japan in the week through Sunday stayed above 1.0, the threshold indicating an epidemic, the health ministry said Friday.

The average number of cases reported by some 5,000 medical institutions came to 1.66, up 0.4 from the preceding week.

The figure had never remained above the threshold in July since the current counting method began in 1999, according to the ministry.

A decline in flu immunity caused by the lack of flu epidemic periods since the COVID-19 outbreak is believed to be behind the ongoing spread of the flu. The March 13 relaxation of the government’s mask-wearing guidelines may also have contributed.

By prefecture, the per-institution number of flu patients was highest in Kagoshima at 27.31, followed by Nagasaki at 9.13 and Miyazaki at 8.83, all in the Kyushu southwestern region.

JIJI Press