Cases of a dangerous and increasingly fatal bacterial infection have reached record levels in Japan. The bacterial infection, called streptococcal toxic shock syndrome (STSS), is spreading in the country, raising questions about what causes it and how to prevent it.
What is STSS?
STSS is a rare but very serious bacterial infection that occurs when bacteria spread into deep tissues and the bloodstream. Common symptoms include fever, muscle pain, and vomiting. Severe symptoms include low blood pressure, swelling, and organ failure, as the body goes into shock.
STSS can develop from minor skin infections or more severe conditions like pneumonia or necrotizing fasciitis. Immediate medical treatment, including antibiotics and supportive care, is critical to manage and improve outcomes for individuals affected by this infection.
According to the Centers for Disease Control and Prevention (CDC), STSS is a “rare but serious” bacterial infection that can “develop very quickly into a life-threatening emergency.”
“Even with treatment, STSS can be deadly. Out of 10 people with STSS, as many as three people will die from the infection,” according to the CDC.
The Japanese National Institute of Infectious Diseases issued an official statement in March 2024, warning that STSS was rising at a rapid rate. As of June 2, Japan’s health ministry had recorded 977 cases of STSS since the start of 2024, which is almost two and a half times the number reported in the United States so far this year, with a mortality rate of up to 30%. Recent figures reveal that 77 people died from the infection between January and March.
The figures for the ongoing outbreak in Japan have surpassed last year’s record of 941 infections—the highest since statistics began in 1999. Additionally, Japan’s National Institute of Infectious Diseases reported 97 deaths due to STSS last year, the second-highest number in the past six years. The 20-death difference in just three months compared to last year is alarming.
What is causing this year’s rise in STSS cases?
The exact cause remains unclear, but health professionals have shared their perspectives and theories. Professor Ken Kikuchi of Tokyo Women’s Medical University suggests the rise could be due to people’s weakened immune systems following COVID-19. “We can boost immunity if we are constantly exposed to bacteria. But that mechanism was absent during the coronavirus pandemic,” Kikuchi said. “So, more people are now susceptible to infection, and that may be one reason for the sharp rise in cases.”
What causes STSS?
As previously mentioned, the typical symptoms of STSS include fever, chills, muscle aches, nausea, and vomiting. Swelling in the arms and legs is also a common symptom. After the first 24 to 48 hours, low blood pressure tends to occur, which can lead to more serious issues including organ failure, an intensified heart rate, and accelerated breathing.
The primary cause of STSS is an infection with group A Streptococcus (GAS) bacteria that produce harmful toxins. These toxins cause a severe immune reaction that results in the serious symptoms of STSS. Bacteria enter the body through the following ways:
- Skin Infections: Minor skin injuries, such as cuts, scrapes, or surgical wounds, can become easy entry points for GAS.
- Respiratory Tract Infections: Conditions such as strep throat or pneumonia caused by GAS can sometimes lead to STSS.
- Invasive Infections: Severe infections such as necrotizing fasciitis (flesh-eating disease) or cellulitis can spread bacteria into the bloodstream, leading to STSS.
- Other Routes: Less common routes include mucous membranes, the vaginal tract, or the rectum.
Once the bacteria are in the bloodstream, they release toxins that can lead to widespread inflammation, organ damage, and the life-threatening symptoms associated with STSS. Immediate medical treatment is essential to manage this condition and prevent it from worsening over time.
