TOKYO: The number of reported cases of so-called swimming pool fever has reached the alert level in 10 of Japan’s 47 prefectures, according to a survey by the National Institute of Infectious Diseases.

Local governments are calling for people to wash hands and avoid sharing towels with others.

Pharyngoconjunctival fever, known as pool fever in Japan, is caused by adenovirus infection and common among children. It is often transmitted by droplets or contact.

Symptoms such as fever, sore throat and pinkeye appear after an incubation period of five to seven days. In many cases, patients recover naturally. Outbreaks often peak in summer, but the disease can spread throughout the year.

According to the institute, 7,635 patients were reported from about 3,000 monitored pediatric hospitals nationwide in the week through Oct. 29. The per-institution count has been at the highest level in 10 years since early September.

By prefecture, Fukuoka had the highest per-institution number of patients at 6.94, followed by 5.81 in Okinawa and 5.22 in Saga. In 10 prefectures including the three, the per-institution figure reached the alert level of three or above.

The disease is spreading mainly in the Kansai western and Kyushu southwestern regions as well as Okinawa Prefecture, southernmost Japan.

The institute on its website recommends prevention measures such as washing hands, disinfecting toys and avoiding sharing towels at nursery schools.

The Fukuoka prefectural government is calling on people who suffer nausea, severe headaches or severe coughing to see a doctor immediately.

JIJI Press