Group A Streptococcus in Japan: Spring 2024 Buzzing Bacteria
Information on "Flesh-eating Bacteria" GAS Infections
The Group A Streptococcus (GAS), or Streptococcus Pyogenesas per its scientific name, is a bacterium with epidemic potential, and an infectious agent whose incidence is constantly monitored by the health authorities, in the same manner as seasonal virus like flu and gastroenteritis.
It usually causes mild diseases, such as strep throat, pharyngitis, acute otitis media, impetigo, and scarlet fever that mainly affect young children during their first years of community life in kindergarten or school. However, it can also cause severe invasive GSA diseases at any age, like:
- Necrotizing fasciitis, also called "flesh-eater" bacteria;
- Postpartum infections;
- Meningitis; and / or,
- Streptococcal Toxic Shock Syndrome (STSS).
The invasive GAS diseases have a high fatality rate and are therefore a matter of concern for health authorities. According to the American Centers for Disease Control and Prevention (CDC) and the international research and public health non-profit organization Institut Pasteur (datas as of March 2021), mortality rates are:
- 10 % overall death rate in GAS diseases;
- 15% for the necrotizing-fasciitis or 1 in 5 people according to the CDC;
- 20% for meningitis;
- 30% or 3 in 10 people in case of STSS.
Post-Covid general increase in GAS infections
The relaxing of sanitary procedures following the Covid-19 🦠 pandemics has recently caused a surge of Group A Streptococcus infections in developed and urbanized countries, and especially of their severe forms. Western countries (including the UK, the Netherlands and Denmark) have been affected as soon as the end of 2022, but contamination has been on the rise in Japan only from the beginning of 2024.
The Japan Times published an article based on Japan’s National Institute of Infectious Diseases (NIID) data, finding that GAS severe infections escalated in a Streptococcal Toxic Shock Syndrome (STSS) according to the following pattern:
- The usual yearly average was 100 to 200 cases;
- But 2019 saw 894 cases;
- 941 STSS in 2023 (including 141 cases and 42 deaths in Tokyo alone); and,
- 517 individuals affected between 2024, January 1rst and March 17.
In the first 2024 quarter, Japanese authorities thus took notice of a rapid increase of severe iGAS leading to STSS in Japan, especially among adults aged 30-40 years old, an age class that seems more predisposed to the streptococcus toxic shock syndrome. Those numbers should also be put into perspective with the overall Japanese population, which was 125,4 million inhabitants in 2023, that is to say a 0,0008% infection rate. Far from the Covid’s figures!
In Western countries, the peak of severe iGAS was reached in 2022 and 2023, depending on the areas, and the disease and fatality rate mainly affected children (less than 18 years old patients). Health authorities found that this uptick was a consequence of the global lifting of the anti-Covid measures: children were indeed exposed to the usual bacteria and germs, but they had an increased risk of developing a secondary GAS bacterial infection after contamination with a respiratory virus.
On the other hand, the current GAS diseases surge is not due to the emergence of a new bacterium strain (contrary to the Covid-19). In Western countries, emm-1 (M1) is the predominant strain, the same that was detected in Japan along with the M1UK strain originating from the UK. This strain is known for causing more severe invasive infections and consequently more fatalities. On a side note, Great Britain has already been affected by GAS severe infection episodic epidemics in the 1980s.
Transmission and reminder of basic hygiene etiquette
Group A streptococcus is actually a bacteria commonly and naturally found in humans, on the skin or on the mucosal lining of the back of the throat.
A GAS disease, whether invasive or not, can be suspected especially in the following cases:
- Symptoms of a sore throat similar to a strep throat or a pharyngitis;
- High fever; or,
- A wound taking too much time to heal or abnormally swollen.
The disease only spreads through human-to-human transmission, mainly by aerosols (droplets or spittle) or through direct face-to-face contact, close contact or prolonged intimacy. Transmission either happens by contact with infected mucous, or by infection of a skin lesion.
While researches are ongoing, currently there is no vaccine against Group A Streptococcus. However, efficient therapy does exist: antibiotic treatments, especially Beta-lactam antibiotics (an antibiotics class including penicillin's byproducts) are widely used against streptococcus-caused diseases.
Contact cases and at-risk individuals
A person is considered a contact-case when they were close to a patient with SGA infection in the 7 days before their symptoms first appeared and up to 24h after the beginning of the patient’s antibiotic therapy.
Individuals who are more at risk of being affected by a severe form are:
- Expectant mothers or who just gave birth;
- New-borns;
- People aged 65 and older;
- Immuno-compromised patients; or,
- People who were recently affected by chicken pox (varicella), a disease known for increasing the risk of GAS’ severe invasive infection.
Situation in Japan and preventive measures
At the time of writing, there is no sign of a particular concern in the Japanese government, neither in the population or residents in Japan. The GAS diseases are monitored the same way as any other contagious disease. At the moment, it seems the GAS diseases are more of a hospital-acquired infections or mainly affect families with young children.
On 2024, March 27, Reuters news agency reported the recommendations of Hitoshi Honda, infectious disease professor at Fujita Health University:
"The disease is not a respiratory illness like pneumonia or COVID-19, so it is unlikely to lead to a pandemic situation. This is a droplet infection. […] Hand hygiene is extremely important for preventing invasive streptococcal infections."
For preventive action, or for at-risk individuals, it is still useful to remind and implement sanitary measures:
- Wear a face mask 😷 in closed or crowded areas (public transports, shopping malls, museums, etc.);
- Maintain a social distance whenever possible;
- Wash your hands frequently and thoroughly, with hydro-alcoholic gel or soap.
Frequent sanitizing and airing of closed rooms also help limiting the spread of the bacteria.
Note that in Japan, most of public places, shops or museums have free and readily available hydro-alcoholic gel. It is also very easy to buy affordable face masks. By the way, you’ll see many Japanese people wearing a face mask now in early spring 🌸: it is mainly a prevention against pollen allergies, especially to the pollen of Japanese cedars (sugi), that are grown almost everywhere in the country. The hay fever season peaks between mid-March and mid-April, with variations depending on the regions.
Official Health Organizations
As the Covid pandemics is still lingering in our daily lives, we are all the more reactive to sensational titles involving a "flesh-eating" bacteria (a condition which is actually very rare). In any case and to avoid any panic, it is best to compare these information with official health organization's statements, such as:
- The CDC in the US;
- The health section of the government of Canada’s official website or any equivalent in your area;
- Your country's embassy in Japan; or,
- The World Health Organization, whose website displays an up-to-date list of the current epidemics. It is possible to check on the situation of a specific country (Japan is located in the Western Pacific zone).
If you had symptoms of a disease caused by a respiratory virus, and / or if the symptoms seem more severe than usual (high fever, abnormal tiredness, or a wound healing too slowly) make sure to get examined by a doctor.
Subscribe to Kanpai-Japan’s Newsletter to make sure to be updated at any change of the situation:
Many media outlets have shared an anxiety inducing AFP news on the GAS for the buzz (or we daresay for "clickbait") as the memories of Japan’s 2,5 years of closing due to the Corona are still vivid. In any case, and at the time of writing, it is not necessary to cancel or postpone a trip to Japan in 2024. All the more as no official announcement or restriction is known at the moment, and insurances don’t cover a trip cancellation over fear alone.