Quick version
Group A streptococci (GAS) are common bacteria, they often cause sore throats or scarlet fever, which are infections that are easy to treat. However, the bacteria can sometimes spread in the body and cause a serious infection called iGAS, this can lead to sepsis (blood poisoning) and other life-threatening conditions.
During the 2023–2024 season, a record number of cases were reported in Sweden, according to the Public Health Agency of Sweden, the increase may be due to poorer immunity after the pandemic.
To protect yourself and others, it is recommended to maintain good hygiene and early testing. For those affected, prompt treatment is the best protection.
What is Group A Streptococcus?
This is a type of streptococcal bacteria that is transmitted through droplet infection or direct contact. Group A streptococci can cause various conditions such as:
- Tonsillitis (tonsillitis)
- Scarlet fever
- Impetigo (swine pox)
- Rash fever (erysipelas)
In most cases, group A streptococcal infections are treated with penicillin, and the sick person usually recovers quickly.
When do group A streptococci become dangerous?
An invasive group A streptococcal infection (abbreviated iGAS) means that the bacteria have spread to different parts of the body that are normally sterile, these parts are the blood, brain or internal organs. When this happens, it can lead to:
- Blood poisoning (sepsis)
- Necrotizing fasciitis
- Toxic shock syndrome
These conditions require immediate hospital care and intensive antibiotic treatment. Early diagnosis can be crucial for a person's survival.
There has been a sharp increase in iGAS in Sweden
According to the Public Health Agency, 1,537 cases of iGAS were reported in Sweden in 2023-2024, compared to 985 in the previous season. Since 2004, when the disease became notifiable, the number of cases in 2023-2024 is the highest reported number.
What is the reason for the increase in iGAS?
According to The Public Health Agency, a likely reason for the increase may be lower immunity in the population after the pandemic. This is because when we isolated ourselves during the Covid years, natural exposure to common bacteria was reduced and this is something that may have made us more susceptible.
Symptoms to watch out for
The following symptoms are important to be especially vigilant about if you or your child experience:
- High fever
- Severe sore throat
- Difficulty breathing
- Swollen lymph nodes
- Rapid deterioration of general condition
Seek medical attention if symptoms are severe or if you are pregnant and suspect infection.
How can you protect yourself against group A streptococci?
To protect yourself and others, it is important to maintain good hygiene and follow the advice below:
- Wash your hands frequently and thoroughly with soap and water
- Avoid close contact with sick people
- Keep children home if they have a sore throat or scarlet fever
- Follow your doctor's advice about antibiotic treatment
In summary, group A strep is often harmless – but in some cases it can lead to life-threatening conditions such as iGAS, which means the infection has become invasive and spread to otherwise sterile parts of the body. Early diagnosis and treatment are crucial to saving lives.
