Why is there currently a lot of reporting about streptococcal infections in Japan?
The reports sound worrying: in the first two months of 2024, a total of 378 cases of streptococcal-induced toxic shock syndrome (STSS) are said to have been registered in Japan. For comparison: In 2023 there were a total of 941 infections.
There are now confirmed cases of STSS in 45 of Japan’s 47 districts. The second largest Japanese newspaper “Asahi Shimbun” writes that younger people in particular are at risk: Of the 65 people under the age of 50 who were diagnosed with STSS between July and December 2023, 21 died – around a third. Health experts fear the disease could spread further.
What is streptococcal-induced shock syndrome?
Streptococcal-induced toxic shock syndrome (STSS) is a rare but life-threatening complication of streptococcal infection. It is usually caused by bacteria from the “Streptococcus pyogenes” group – or A streptococci. These bacteria not only cause an excessively strong immune reaction in the body, killing the body’s own cells that are infected. The bacteria also have a toxic, i.e. toxic, effect. The shock syndrome also became known as “tampon disease”. The blood-soaked tampon in warm, moist milleu offers good conditions for the bacteria to multiply. It becomes dangerous when these bacteria secrete toxins and these end up in the bloodstream.
The result: circulatory shock can occur and lead to vital organ failure. “There is a massive activation of the immune system, a so-called cytokine storm. Ultimately, organs such as the kidneys, liver, heart and brain no longer receive sufficient blood supply,” explains Prof. Dr. Siegbert Rieg, Head of the Infectious Diseases Department at the Clinic for Internal Medicine II at the University Hospital of Freiburg. “Then the patients become very seriously ill in a very short space of time. Typical symptoms include muscle cramps, fever, low blood pressure, nausea or vomiting. In the worst case, multi-organ failure occurs.” This is the term used to describe the simultaneous or successive failure of several important organs.
According to the Robert Koch Institute (RKI), around 30 percent of STSS cases are fatal. It is not yet known exactly why this syndrome is currently occurring more frequently in Japan. “It is probably the case that our immune system has had to deal less with streptococci over the past three or four years due to the Covid pandemic and social distancing, masks and increased hygiene measures and is therefore somewhat more susceptible,” says Prof. Rieg.
What kind of pathogens are streptococci?
Streptococci are non-motile spherical bacteria that arrange themselves in chains or pairs and are part of the natural human microbiome. They colonize the skin and mucous membranes, the intestines, mouth and throat. Most of the time these bacteria are completely harmless and are not even noticed.
However, streptococci can also make you sick. The so-called A streptococci are particularly medically relevant. Among other things, they can trigger infections of the upper respiratory tract – such as sinus, throat and tonsillitis or the childhood illness scarlet fever. “A streptococci can also penetrate the body through inflammatory areas of the skin,” says Prof. Rieg. “And sometimes the portal of entry cannot be traced.” One thing is certain: the dreaded streptococci-induced toxic shock syndrome is predominantly triggered by group A bacteria.
How quickly does the pathogen spread and what does that mean?
Streptococci can be transmitted via droplet infection or direct skin contact, for example through open wounds. According to the RKI, the bacterium cannot multiply in an inanimate environment, but it can survive on dry surfaces in mucus or blood residues for up to several months and remain infectious.
To protect yourself, you should use simple hygiene measures like those already known from the corona pandemic – such as washing your hands frequently and thoroughly. If symptoms of a streptococcal infection appear, antibiotic therapy should be started immediately. “Streptococci are treated with penicillin,” says Prof. Rieg. “In severe forms, a second antibiotic is also given – and in particularly severe cases, intravenous immunoglobulins to regulate the inflammation.”
These are infections, pathogens and complications that we have known about for many years. This is not a new phenomenon.
What does that mean for us in Germany?
“My assessment is that the Japanese are going through what we experienced last winter: a significant peak in Streptococcus pyogenes infections in all age groups. The fact that the infections appear simultaneously throughout Japan speaks against an outbreak with a special epidemic strain,” says Prof. Dr. Andreas Podbielski, Director of the Institute for Medical Microbiology, Virology and Hygiene at the Rostock University Medical Center. “What is happening now started with the children as typically infected people, then followed the adults who had contact with children and then all other adults. And if there are a lot of Streptococcus pyogenes infections, the number of dramatic ones naturally increases.” An assessment that Prof. Rieg also confirms: “When I talk to colleagues from clinical infectious disease medicine, we agree that We have had to deal with more severe A streptococcal infections in recent months. Unfortunately, we cannot support this with clearly formulated data.”
According to the RKI, group A streptococcal infections in Germany are currently not reportable under the Infection Protection Act. “But mind you: these are infections, pathogens and complications that we have known about for many years. This is not a new phenomenon.”