Mysterious, dangerous bacterial infections spreading in Japan

A mysterious strep bacterium has been spreading in Japan, resulting in an increase in deadly infections.

Media outlets cited experts warning that the harshest and potentially deadly form of streptococcus pyogenes, which is highly virulent and infectious, is spreading at a record rate in Japan, with officials struggling to identify the cause of the epidemic.

Streptococcal bacterium, more commonly known as strep A, can cause sore throats, mainly in children, and lots of people have it without knowing it and do not become ill.

However, the rare streptococcal toxic shock syndrome (STSS) can cause serious illnesses, health complications and death, particularly in adults over 30 who can experience cold-like symptoms; but, in rare cases, the symptoms can worsen to include strep throat, tonsillitis, pneumonia and meningitis. In the most serious cases, it can lead to organ failure and necrosis.

It is estimated that about 30 percent of STSS cases are fatal.

“There are still many unknown factors regarding the mechanisms behind fulminant (severe and sudden) forms of streptococcus, and we are not at the stage where we can explain them,” according to the National Institute of Infectious Diseases (NIID), which released provisional figures showing it had recorded 941 cases of STSS reported last year. In 2024, 378 cases have already been recorded in the first two months, with infections identified in all but two of Japan’s 47 prefectures.

Experts expect the number of cases to grow, linking the fast spread of the disease to the lifting of restrictions imposed during the coronavirus pandemic.

Japan’s government downgraded COVID-19’s status from class two – which includes tuberculosis and Sars – to class five, placing it in May 2023 on a legal par with seasonal flu.

This shift in status meant local authorities were no longer able to order infected people to stay away from work or to recommend hospitalization.

This also prompted people to lower their guard against infectious diseases, in a country where widespread mask-wearing, hand sanitizing and avoiding the “three Cs” were credited with keeping COVID-19 deaths comparatively low.

The “three Cs”, according to Japan’s Ministry of Health, Labour and Welfare, are 1)Closed spaces, 2)Crowded places, and 3)Close-contact settings.

I am “very concerned” about the current situation, says Ken Kikuchi, a professor of infectious diseases at Tokyo Women’s Medical University. He believes lowering the status of COVID last year led people to abandon their basic hygiene measures which are the most important factor behind the increase in streptococcus pyogenes infections.

“In my opinion, over 50 percent of the Japanese people have been infected by Sars-CoV-2 [the virus that causes COVID-19],” Kikuchi said in an interview with the Guardian.

“People’s immunological status after recovering from COVID-19 might alter their susceptibility to some microorganisms. We need to clarify the infection cycle of severe invasive streptococcal pyogenes diseases and get them under control immediately.”

The spread of streptococcal infections is similar to COVID-19, spreading through droplets and physical contact, as well as through wounds on the hands and feet.

Common treatment of Strep A infections is antibiotics; however, severe cases will likely need a combination of antibiotics and other drugs, along with intensive medical attention.

Japan’s Ministry of Health, Labour and Welfare recommends people resume the hygiene level they had during the COVID-19 pandemic to stop the spread of strep A.

“We want people to take preventive steps such as keeping your fingers and hands clean, and exercising cough etiquette,” Keizo Takemi said earlier this year.

With a population of 125.7mn people, Japan recorded 33,8mn cases of COVID-19 of which 74,694 instances were fatal.