You may have heard reports of a recent outbreak of a “flesh-eating bacteria” in Japan that causes the disease known as streptococcal toxic shock syndrome (STSS).
Media reports suggest that the country has seen over 1,000 cases of STSS in the first six months of 2024, more than the total number in 2023. However, these cases have not yet been published in peer-reviewed journals, so the reports may not be completely accurate.
The cause of STSS is Streptococcus pyogenes bacteria, or “strep A.” These bacteria are fairly common, but certain strains can cause a more serious illness — called invasive group A streptococcal disease.
An increase in severe invasive group A streptococcal disease has been observed in many countries, including Australia, the United States, and countries in Europe, since 2022. This surge is part of an overall increase in strep A infections.
So what is STSS, why is it on the rise now, and is it a cause for concern?
Who gets STSS?
At any given time, several people will be “infected” with strep A, meaning the bacteria will survive harmlessly in their throat or on their skin.
Strep A also causes sore throat (“strep throat”) and skin infections. Sometimes, for reasons that are still not entirely clear, strep A causes pneumonia, nasty “flesh-eating” skin infections, and invasive infections such as STSS. In these ways, strep A is an important cause of sepsis, a term that broadly refers to infections that pose a threat to life.
STSS is the most serious strep A illness, although luckily it is really rare. It mostly affects young children and the elderly, but cases occur in people of all ages. Pregnant women may also be at higher risk, including immediately after delivery.
what are the symptoms?
In STSS, the bacteria produce a toxin that can result in an extreme immune reaction in some people.
The disease can become life-threatening within hours and has a high mortality rate — up to 40 percent of people with STSS die.
However, the early signs and symptoms of STSS can resemble those of common viral illnesses, especially in children, making it difficult to diagnose.
Early invasive group A streptococcal infections tend to have nonspecific symptoms — things like fever, rash and nausea. But it's important to watch for signs of sepsis, which could indicate something more serious may be going on.
The symptoms of more severe invasive group A streptococcal disease, including STSS, are similar to those seen in other bacterial causes of sepsis (such as meningococcal disease). These include lethargy (drowsiness), rapid breathing, a rapidly changing rash, muscle aches, and confusion.
STSS sometimes occurs with a condition called necrotizing fasciitis, caused by strep A, which is the “flesh-eating” form of the infection. It occurs when skin cells die in response to toxins produced by the bacteria.
Parents of young children should trust their intuition. If you are concerned that your child is sicker than a normal germ illness, and especially if he or she has cold hands and feet, a rash (like sunburn), or is less responsive, seek medical help immediately at your nearest emergency department.
Why now?
Studies suggest that some of the more virulent types of Strep A may be a part of the current STSS surge.
In addition, in 2020-21, at the height of the COVID pandemic, when there was less close contact between people, there was also less exposure to strep A (and other bacteria and viruses). For young children in particular, this meant they did not develop the partial protection against nasty strep A infections that come with repeated exposure.
Due to greater human contact since 2022, there has been more transmission of strep A, which is at greater risk of causing more severe disease, including STSS in children.
It is not limited to Japan. Although it is rare, we have seen several cases of STSS in Australia and elsewhere.
How is STSS treated and can we prevent it?
Strep A can be killed by penicillin, one of the oldest and most widely available antibiotics. When STSS is diagnosed early, antibiotics usually prevent most of the serious complications.
Other medications, such as immunoglobulin, may be needed to stop the uncontrolled immune response, and patients often require support in the intensive care unit.
There is no vaccine to prevent STSS and other strep A infections (unlike other bacteria such as meningococcus and pneumococcus, which are included in the national childhood immunization schedule).
Researchers in Australia and around the world are working hard to find a vaccine to prevent strep A infection.
Serious strep A infections such as STSS often follow viral infections, particularly chickenpox and influenza, so keeping up to date with vaccines given in the national schedule (which includes chickenpox), and making sure you get the seasonal influenza vaccine, reduces the risk.
Strep A can be spread through large respiratory droplets or through direct contact with infected people or carriers. Simple hygiene measures (such as washing hands and covering your cough) reduce the amount of strep A that is transmitted in the community.
Planning a trip to Japan? Then no need to cancel your holidays
STSS is a rare but serious complication of strep A infection, which can occur anywhere in humans. So, unless you're traveling alone to the South Pole, you have a very similar (and very low) risk of getting a serious infection.
Make sure you have all your vaccinations, including the seasonal flu vaccine. Always maintain good hand hygiene and be aware of the symptoms of serious bacterial infections that require immediate medical attention.
Phoebe Williams, paediatrician and infectious disease physician; Senior Lecturer and NHMRC Fellow, Faculty of Medicine, University of Sydney; Joshua Osowiecki, Team Leader, Research Fellow, Paediatric Infectious Disease Physician, Murdoch Children's Research Institute, and Yara-Natalie Abo, General Paediatrician and Paediatric Infectious Disease Physician, PhD Candidate, Clinical Vaccine Trial Lead, Murdoch Children's Research Institute
This article is republished from The Conversation under a Creative Commons license. Read the original article.