Flesh-eating bacteria that can kill in two days spreads faster than ever in Japan

A rare and deadly disease caused by a "flesh-eating" bacteria is spreading rapidly in Japan, particularly in Tokyo. Streptococcal toxic shock syndrome (STSS) is an aggressive illness that can be fatal within 48 hours of infection.

Tokyo alone reported 145 cases in the first half of 2024. The majority of cases are in adults over 30, while the death rate has hovered at around 30 per cent, as per a report by local newspaper Asahi Shimbun.

As of June 2, STSS cases nationwide have reached 977, surpassing last year's total of 941 cases, as reported by Japan's National Infectious Disease Institute.


Group A Streptococcus (GAS) often results in a common condition known as "strep throat" in children, which causes swelling and a sore throat.

However, certain strains of this bacterium can cause severe and rapidly progressing symptoms such as limb pain and swelling, fever, and low blood pressure. These symptoms can escalate to necrosis, respiratory issues, organ failure, and even death. Individuals over the age of 50 are particularly susceptible to these severe outcomes.

“Most of the deaths happen within 48 hours,” Ken Kikuchi, a professor in infectious diseases at Tokyo Women’s Medical University, told Bloomberg. “As soon as a patient notices swelling in foot in the morning, it can expand to the knee by noon, and they can die within 48 hours.”

At least five European nations reported to the World Health Organization an increase in cases of invasive group A streptococcus (iGAS) disease, which includes STSS, in 2022.

The WHO said the rise in cases followed the end of Covid restrictions.

At the current rate of infections, the number of cases in Japan could reach 2,500 this year, with a “terrifying” mortality rate of 30%, Kikuchi said.