An alarming progression of “flesh-eating” bacteria, fatal in a third of cases

A number of contagions that are going out of control. A large part of the archipelago is affected. through a potentially fatal “flesh-eating” disease. Japan is currently facing this alarming situation. In recent months, the country has seen an unprecedented rise in cases of streptococcal toxic shock syndrome (SSTS) caused by bacteria: Group A streptococci (GAS or pyogenic streptococci).

How to explain this increase? How to contain it? And should we be concerned about the progression of this “meat-eating” disease?

A more virulent strain with higher transmissibility

SCTS has been relatively infrequent since first reported in Japan in 1992. Since then, about 100 to 200 cases have been reported each year in the Japanese archipelago. But the situation worsened in 2023, with 941 cases reported by the National Institute of Infectious Diseases (NIID), which has reported 422 cases between January 1 and March 17 this year. Rapid progress indicating record number of contaminants for 2024.

These figures are all the more alarming because at the same time, in the summer of 2023, Japanese authorities discovered an SGA of the M1UK line for the first time in Japan. A strain identified in the United Kingdom, which is most common in Europe, and which is known to be more virulent and more transmissible. One variant is “characterized by mutations that improve the expression of certain factors involved in the virus and may explain the increase in invasive GAS infections in recent years in the United Kingdom”, suggests Public Health France.

High death rate

However, most people infected with GAS show no symptoms, or have mild symptoms such as a sore throat and skin infection. But in the most severe cases, SCTS can cause necrosis of fascia, the connective tissue that covers muscles, earning it the dreaded nickname “flesh-eating disease.” Patients are treated with antibiotics, but in case of severe complications, removal of infected tissue is indicated.

Ken Kikuchi, a professor of infectious diseases at Tokyo Women’s Medical University, said. guardian A sharp increase this year in the number of patients with severe invasive streptococcal infections is to be “very concerning”. And in rare cases where the bacteria reaches the bloodstream, muscles and lungs, the disease can lead to low blood pressure, multiple organ failure or death, Japanese officials warn.

Thus, approximately 30% of SCTS cases are fatal. And while the elderly are considered most at risk, SGA is associated with high mortality even among infected people under 50, the NIID underscores. The Asahi Shimbun newspaper reports that of 65 patients under the age of 50 diagnosed with STSS between July and December 2023, 21 of them, or about a third, died. A mystery to Japanese health officials. “There are still many unknown factors regarding the mechanisms behind the fulminant (severe and sudden) forms of streptococcus, and we are not at the stage where we can explain them,” NIID responded.

Identify the cause of this infection

If, for the moment, the exact cause of this outbreak is unknown, it is most likely associated with a resurgence in respiratory diseases, which was announced by the Minister of Health, Keizo Takemi, last January. Japan Times. and the Kovid-19 pandemic. “In my opinion, more than 50% of Japanese have been infected with SARS-CoV-2,” estimates Professor Kikuchi. The immune status of people who have recovered from Covid-19 may alter their susceptibility to certain microorganisms, he argued. We need to clarify the infection cycle of severe invasive streptococcal pyogenic diseases and bring them under immediate control.”

In May 2023, Japan, whose population has long been accustomed to wearing masks, has entered a post-pandemic phase: the authorities have downgraded Covid-19, until it is considered a second-tier disease like Severe Acute Respiratory Syndrome (SARS) or tuberculosis. . It is considered a Category 5 disease, at the same level as seasonal flu. Re-eligibility in 2020 with the relaxation of a range of health restrictions put in place at the start of the pandemic.

However, like Covid-19, group A streptococcus is transmitted through aerosols – the famous droplets – and through close contact, Japan’s health minister has clarified. But not only that. According to the American Centers for Disease Control and Prevention (CDC), bacteria can also enter the body through wounds. For Japan’s Ministry of Health, good hygiene is crucial. “We want people to take preventive measures, such as washing their hands when they cough and respecting health rules,” the health minister, Keizo Takemi, urged last January, reports Japan Times. Actions include wearing a mask when coughing, coughing into a tissue or your elbow, or washing your hands regularly with soap and water or a hydroalcoholic solution.