Influenza is usually prevalent from December to March.

The number of patients per medical institution for the week ending May 12 was 3.5, the first time since 28 years ago that the number of patients exceeded "1", which is a guideline for an epidemic in late May.

The number of patients with "RS virus infection" and "herpangina", a typical infectious disease of summer cold, is also increasing.

Why is it on the rise now? We asked the experts.

Influenza Unseasonable Epidemic

Schools across the country have been closed one after another due to seasonal influenza outbreaks.

According to the National Institute of Infectious Diseases, 5,28 influenza cases were reported by approximately 1,5000 medical institutions nationwide in the week ending May 7975, and the number of patients per medical institution was 1.1.

Influenza is usually prevalent from December to March, but it will be the first time in 62 years since 12 that the number of patients per medical institution exceeded "one" in late May.

In the past week, 1 schools have been closed or grades and classes have been closed nationwide, including 246 elementary schools,
40 junior high schools,

and
25 high schools.

In May, high schools in Oita City and Miyazaki City were closed due to a cluster of nearly 325 people each, and since the beginning of June, about 5 junior and senior high schools in Fukuoka City have been closed due to infection with the new coronavirus and influenza.

RS virus and herpangina also increased

In addition, the number of patients with "RS virus infection", which is prevalent from summer to autumn every year, mainly among children, and "herpangina", a viral infection typical of summer colds that is often seen in infants, is also increasing.

In the week ending May 5, approximately 28,1 pediatric medical institutions reported 3000.1 cases per pediatric clinic, both of which increased for the third consecutive week, with 1.95 cases for "RS virus infection" and 1.33 cases for "herpangina".

Compared to the week before the transition to Class 5, the number of RS virus infections has doubled, and the number of herpangina has increased fivefold.

The Ministry of Health, Labour and Welfare (MHLW) says, "As socio-economic activities return to normal, seasonal factors are expected to cause certain epidemics in the future, so we will pay close attention to the epidemic situation of various infectious diseases."

Experts Weakened immunity is the cause?

Project Professor Atsuro Hamada of Tokyo Medical University, who is an expert on infectious diseases, said, "Both infectious diseases may be caused by the fact that there have not been many major outbreaks and immunity has declined considerably against the backdrop of a sharp decrease in international travel and the implementation of strict infection control measures in the past three years since the spread of the new coronavirus. I pointed out.

Regarding future measures, he said, "It is not realistic for everyone to return to their old lives, such as wearing masks all the time, but it is effective to take measures when infectious diseases begin to spread around us, such as in school classes and at home. It is important to rest and be careful not to spread the word to others, and if the symptoms are severe, visit a hospital. I think this will lead to recovery from symptoms and prevention of the spread of infection."