Japan's FUKUOKA seasonal flu continues to spread

The FUKUOKA seasonal flu has been circulating across Japan for the first time in three years after strict COVID 19 countermeasures seem to have helped keep flu infections at relatively low levels in 2021 and 2022.

The number of flu patients in western Japan has been on the rise this winter, with some regions seeing the outbreaks reach alert levels, apparently due to the relaxation of anti-COVID 19 measures. Experts warn that flu infections may spread more quickly than normal years.

The Ministry of Health, Labor and Welfare announced on February 3 that the number of flu patients in the country has reached warning levels for the first time in three years. The number of patients per medical institution stood at 10.36 during the week up to January 29, surpassing the warning level of 10 per institution.

The ministry said the number of flu patients per medical institution had reached 1.24 during the week up to December 25, 2022, well above the criteria for an epidemic at 1 per establishment. Flu infections went up in January, with the number of patients jumping to 9.59 per institution over the week until January 22.

What is the cause of a thriving flu?

According to Hiroyuki Moriuchi, a Nagasaki University Hospital professor and pediatric infectious diseases specialist, people have a weakened immune system due to increased anti-coronaviruses measures in 2021 and 2022, and there have been increased traffic between Japan and abroad and relaxed countermeasures against infections in the country. The spread of the coronavirus and the influenza has been a serious blow to medical institutions.

It's difficult to know whether a patient has been infected with the coronavirus or flu based solely on their symptoms, said Michiko Kurokawa, director of the Kurokawa Michiko Pediatric ClinicKurokawa Michiko Pediatric Clinic in the city of Fukuoka.

When a patient visits her clinic, staff first test her with kits that can detect both the coronavirus and flu, before examining them in different rooms based on the test results. Over the past four days, about 20% of patients who tested positive had the coronaviruses, while the remaining 80% had the flu.

Even if patients get tested, test results may not necessarily come back positive for the first several hours after developing a fever. Kurokawa said that if patients develop a high fever, they need to be tested again if they are dehydrated, so they are advised to take adequate water, even if they are negative. Professor Moriuchi warned that the flu can cause life-threatening complications, such as encephalopathy. If patients have symptoms such as convulsions, grogginess, or utter strange things, they are advised to call emergency services immediately. While flu infections usually peak in early February, Moriuchi said that the flu outbreak may continue due to deteriorating herd immunity and changes in people's lifestyles.