Mysterious infection hits Japan: every third person dies

A rare but dangerous bacterial infection is spreading at a record pace in Japan, and health officials are struggling to determine the cause, experts are warning.

The number of cases in 2024 is expected to exceed last year’s record levels, while concerns are growing that the most severe and potentially fatal form of group A streptococcal disease, streptococcal toxic shock syndrome (STSS), will continue to spread after being confirmed in Japan. the presence of highly virulent and infectious strains was confirmed.

The National Institute of Infectious Diseases (NIID) said: “There are still many unknown factors regarding the mechanisms underlying fulminant (severe and sudden) forms of streptococcus, and we are not at the stage where we can explain them.”

According to preliminary data released by the NIID, there were 941 cases of streptococcal toxic shock syndrome reported last year. There have already been 378 cases reported in the first two months of 2024, with infections detected in all but two of Japan’s 47 prefectures.

While older people are considered to be at greater risk, the group A strain is associated with more deaths among patients under 50, according to the NIID. Of the 65 people under age 50 who were diagnosed with streptococcal toxic shock syndrome between July and December 2023, about a third, or 21 people, died, the Asahi Shimbun newspaper reported.

Most cases of streptococcal toxic shock syndrome are caused by a bacterium called streptococcus pyogenes. More commonly known as streptococcus A, it can cause a sore throat, mainly in children, and many people have it without knowing it and don’t get sick.

But the highly contagious bacteria that cause the infection can in some cases cause serious illness, health complications and death, especially in adults over 30. About 30% of cases of streptococcal toxic shock syndrome are fatal.

Older adults may experience cold-like symptoms, but in rare cases, symptoms may worsen, including strep throat, tonsillitis, pneumonia, and meningitis. In the most severe cases, this can lead to organ failure and necrosis.

Some experts believe the rapid rise in cases last year was linked to the easing of restrictions imposed during the coronavirus pandemic.

In May 2023, the government downgraded the status of Covid-19 from class two, which includes tuberculosis and SARS, to class five, putting it on par with seasonal influenza. This change meant that local authorities could no longer order infected people not to go to work or recommend hospitalization.

The move also prompted people to lower their guard in a country where widespread mask-wearing and disinfection were thought to have contributed to the comparatively low death rate from the coronavirus. There have been about 73,000 deaths from Covid-19, compared with more than 220,000 in Britain, which has a population just over half that of Japan.

Ken Kikuchi, a professor of infectious diseases at Tokyo Women’s Medical University, says he is “very concerned” about the sharp rise in the number of patients with severe invasive streptococcal infections this year.

He believes the reclassification of Covid-19 was the most important factor behind the increase in streptococcus pyogenes infections. This, he added, has led more people to abandon basic infection prevention measures such as regular hand disinfection.

“In my opinion, more than 50% of Japanese people have been infected with Sars-CoV-2 [вирусом, вызывающим Covid-19]”, Kikuchi tells the Guardian. “The immunological status of people after recovery from Covid-19 may change their susceptibility to certain microorganisms. We need to clarify the infectious cycle of severe invasive streptococcal pyogenic diseases and bring them under control immediately.”

Streptococcal infections such as Covid-19 are spread through airborne droplets and physical contact. The bacterium can also infect patients through wounds on the arms and legs.

Type A streptococcal infections are treated with antibiotics, but patients with more severe invasive group A streptococcal diseases will likely require a combination of antibiotics and other drugs, as well as intensive medical care.

Japan’s Ministry of Health recommends that people take the same basic hygiene precautions against streptococcus A that have become part of everyday life during the coronavirus pandemic.

“We want people to take preventive measures, such as keeping their fingers and hands clean and practicing cough etiquette,” Health Minister Keizo Takemi told reporters earlier this year, The Japan Times reported.