The number of STSS cases touched 977 this year by June 2, a record higher than that of last year's 941 reported cases, said the National Institute of Infectious Diseases, which has been tracking the disease since 1999.

Group A Streptococcus (GAS) generally causes swelling and sore throat in children, also known as "step throat". However, some types of bacteria can also lead to rapidly developing systems such as limb pain, swelling, fever, low blood pressure etc. These symptoms can then by followed by necrosis, breathing problems, organ failure and death. People over the age of 50 are more prone to this disease, the report added.

A professor in infectious diseases at Tokyo Women's Medical University, Ken Kikuchi, said that most of the deaths taken place within 48 hours.

"As soon as a patient notices swelling in the foot in the morning, it can expand to the knee by noon, and they can die within 48 hours," Kikuchi was quoted as saying.

Notably, at least five European nations reported a surge in cases of invasive GAS disease, including STSS to the World Health Organisation in late 2022. The UN agency said that the increase in the cases came after the end of Covid restrictions.

Meanwhile, Kikuchi noted that at the current rate of infections, the number of cases in Japan could go up to 2,500 this year and that too with a "terrifying" mortality rate of 30 per cent.

He urged citizens to maintain their hand hygiene and treat any open wounds. Kikuchi said that several patients might also carry GAS in their intestines, which could contaminate hands through excrement.