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Electron micrograph of group A streptococcus (Streptococcus pyogenes) on primary human neutrophils. Group A streptococcus is one of the main causes of STSS.
CNN
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Cases of a dangerous and highly deadly bacterial infection in Japan have reached record levels, according to official statistics, but experts are yet to pinpoint the reason for the increase.
Japan’s Ministry of Health, Labor and Welfare has recorded 977 cases of streptococcal toxic shock syndrome (STSS), which has a fatality rate of up to 30 percent, as of June 2. Some 77 people died from the infection between January and March, according to the latest figures available.
The ongoing spread of the virus in Japan has already surpassed the previous record of 941 cases last year, the highest number since statistics began in 1999. report Last year, 97 people died from STSS, the second highest number of deaths in the past six years.
STSS is a rare but serious bacterial infection caused by the spread of bacteria to deep tissues and the bloodstream. Patients initially suffer from symptoms such as fever, muscle pain and vomiting, but symptoms such as low blood pressure, swelling and multiple organ failure can rapidly develop as the body goes into shock and the condition can become life-threatening.
“Even with treatment, STSS can be fatal. Up to 3 of 10 people with STSS will die from the infection,” says the U.S. Centers for Disease Control and Prevention (CDC).
Most cases of STSS are caused by Group A Streptococcus (GAS), which causes fever and throat infections, mainly in children. In rare cases, Streptococcus A can produce toxins that enter the bloodstream and cause severe illness, including toxic shock.
Group A strep can also cause “flesh-eating” necrotizing fasciitis that can lead to limb loss, but most people who get the disease have other health conditions, such as cancer or diabetes, that can reduce the body’s ability to fight off infection, according to the CDC.
Invasive group A streptococcal infections had been largely contained due to COVID-19 prevention measures such as mask-wearing and social distancing, but many countries reported an increase in the number of infections after these measures were relaxed.
In December 2022, five European countries report The World Health Organization reports an increase in invasive group A streptococci (iGAS), Children under 10 years old The CDC has been most affected. investigating The disease was clearly on the rise at that time.
In March, Japanese authorities warned that cases of STSS were rising sharply. release The risk assessment states that the number of STSS cases due to iGAS has “increased since July 2023, particularly among people under the age of 50.”
The CDC says older adults with open wounds, including those who have recently had surgery, are at higher risk for developing STSS.
“However, experts don’t know how the bacteria got into the body in nearly half of people with STSS,” the CDC said on its website.
The reason for the increase in STSS cases in Japan this year remains unclear, according to Japanese public broadcaster NHK.
Professor Takeshi Kikuchi of Tokyo Women’s Medical University said: He spoke to NHK This increase may be due to a weakening of people’s immunity as a result of the spread of COVID-19.
“Constant exposure to bacteria can boost immunity, but that mechanism wasn’t working during the coronavirus pandemic,” Kikuchi said. “As a result, more people are susceptible to infection, which may be one of the reasons for the sudden increase in infections.”