Japan was struck by a mysterious flesh-eating bacterium – every third person dies: what is known about the dangerous infection and why experts cannot explain the dangerous disease

A new deadly virus in Japan has alarmed scientists around the world as a dangerous bacterial infection is spreading in the land of the rising sun. Currently, more than 378 people have been hospitalized with identified signs of streptococcal toxic shock syndrome. 

A mysterious disease is rampant in Japan, where the number of dangerous streptococcal infections has reached record levels. Health officials are racing to determine the cause of a rise in streptococcal toxic shock syndrome, which carries a 30% fatality rate.

Experts note that for the entire 2023, 941 cases of infection were registered in Japan, which is three times more than years earlier. Scientists fear an exponential progression in the spread of the virus.

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.

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

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.

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.”

It was first discovered in 1978. For a long time, toxic shock syndrome was considered by most people to be “tampon disease.” This opinion arose on the basis of data from US scientists who conducted a study and found that the majority of patients were women, and the infection occurred during the menstrual cycle. A national investigation was launched and then a report was released linking STSS to tampon use.

Toxic shock syndrome is a severe lesion of various organs and systems of the body, which is caused by exotoxins of Staphylococcus aureus or Streptococcus pyogenes. It manifests itself as a sudden fever with a temperature of 39 degrees or more, a sharp drop in blood pressure, skin rashes followed by peeling, diarrhea, and vomiting.

In severe cases of the disease, toxic shock may develop, which leads to impaired microcirculation, respiratory failure, shortness of breath, heart rhythm disturbances, liver damage and kidney failure. Necrotizing fasciitis occurs – this bacterium is also called carnivorous because it causes tissue death. In general, this disease is manifested by the development of multiple organ failure, that is, it “hits” several organs at the same time. As the condition worsens, the patient falls into a coma.

The mortality rate from infection is quite high – up to 30%, even despite aggressive treatment. Experts note that approximately every third patient in STSS dies. The risk of development further increases in the presence of diabetes mellitus, alcoholism, and infection with the varicella zoster virus. People from 20 to 50 years old, both men and women, are at risk.

Specialists are aware of the difficult epidemiological situation in Japan and carefully monitor it, which allows them to ensure stable preparedness for the emergence and spread of various infections and diseases, including streptococcal toxic shock syndrome. 

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.

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 all hygiene precautions against streptococcus A that have become part of everyday life during the coronavirus era.

“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.