Cases of streptococcal toxic shock syndrome, or STSS, have hit a record high in Japan. The bacterial infection develops rapidly and can be fatal.
STSS is caused mainly by the "group A streptococcus" bacterium and mostly affects people in their 30s or older. Patients can develop necrosis of the limbs and suffer multiple organ failures.
Japan's National Institute of Infectious Diseases says the preliminary number of cases in the country since the beginning of this year totaled 977 as of June 2.
That's a 2.8-fold increase from the same period last year and more than that year's total of 941, which was the highest figure ever registered with the current data-taking method.
Tokyo Women's Medical University Professor Kikuchi Ken says STSS bacteria are often said to enter the body through a wound, but in some cases the cause of infection cannot be pinpointed. He notes there are instances in which symptoms develop rapidly after getting bruised, such as in a fall.
Kikuchi says the surge in patients alarms him as it indicates something new is happening.
He urges people to call an ambulance immediately if swelling spreads rapidly, if they develop high fever, or if they feel drowsy, as these symptoms require urgent medical attention.