A disease caused by a rare “flesh-eating bacteria” that can kill people within 48 hours is spreading in Japan after the country eased Covid-era restrictions, Bloomberg reported on Saturday.

Streptococcal toxic shock syndrome (STSS) is an aggressive disease that can be fatal within 48 hours of infection.

According to the National Institute of Infectious Diseases, which has been tracking the incidence of the disease since 1999, 977 cases of STSS have been reported in Japan as of June 2 this year, up from the 941 cases reported last year.

Group A Streptococcus (GAS) commonly causes a swollen and sore throat in children, known as “strep throat,” according to Bloomberg, but certain types of the bacteria can rapidly develop symptoms, including pain and swelling in the limbs, fever, low blood pressure, followed by necrosis, breathing problems, organ failure and death.

“Most deaths occur within 48 hours,” said Ken Kikuchi, a professor of infectious diseases at Tokyo Women’s Medical University. “While patients develop leg swelling in the morning, by afternoon it can spread to the knee and they can die within 48 hours,” he added.

People over the age of 50 are at higher risk of this disease.

Kikuchi said that at the current rate of infection, the number of cases in Japan could reach 2,500 this year, and the mortality rate could reach 30%.

Kikuchi urged people to maintain good hand hygiene and treat open wounds. She said patients may have gas in their intestines, which can contaminate hands through feces.

In addition to Japan, several other countries have recently experienced outbreaks of streptococcal toxic shock syndrome, according to Bloomberg. In late 2022, at least five European countries reported to the World Health Organization an increase in cases of invasive group A streptococcus (iGAS) disease, which includes STSS. The WHO said the increase in cases occurred after COVID restrictions were lifted.