TOKYO: Streptococcal toxic shock syndrome, a potentially fatal illness caused by a "flesh-eating" bacterium, is increasing notably across Japan, with cases in the first half of this year already exceeding last year's record, Xinhua cited local media reports Tuesday.

There have been 977 confirmed cases of the disease caused by the bacterium called streptococcus pyogenes which is often associated with strep throat but occasionally leads to limb necrosis and multiple organ failure, Kyodo News reported, citing a national infectious disease institute.

The figure in the first six months of 2024 already surpassed last year's 941, the highest annual number of cases tallied since mandatory reporting began in 1999, the report said.

Tokyo logged the highest number of cases at 145. Infections of more virulent and contagious strains of the bacterium are increasingly being reported, particularly in the Kanto region centering on Tokyo, it added.

Ken Kikuchi, a professor specialising in infectious disease at Tokyo Women's Medical University, said foot wounds are particularly susceptible to streptococcal bacterial infection, and small injuries like blisters and athlete's foot can be entry points, adding that it can take as little as 48 hours from infection to death in elderly patients.

"High fever accompanied by delirium or rapid swelling of wounds are dangerous signs", and immediate medical attention should be sought, he said.