Group A streptococcus (GAS) is a common bacteria that's caught the attention of doctors in Australia, the UK and Europe. As this bacteria can cause a range of infections, we're going to take a look at exactly what group A streptococcus disease is, how it's spread, the signs and symptoms, and the treatments available for it.

Just remember that if you need support or someone to talk to, our Sonder support team is available 24/7 to chat whenever you need it.


What exactly is group A streptococcus disease?

GAS infection is caused by a type of bacteria known as Group A (beta-haemolytic) Streptococcus, the most common type of which is Streptococcus pyogenes.

GAS infections are pretty common and are generally found in the throat and on the skin. These infections come in the form of pharyngitis, scarlet fever or impetigo (school sores).

In rare cases, the bacteria can cause a severe, life-threatening infection known as invasive group A streptococcal disease (iGAS). The most severe forms of iGAS infections include necrotising fasciitis (or flesh-eating bacteria), streptococcal toxic shock syndrome, and rheumatic fever.

Anyone can develop group A streptococcal disease, but people who are most at risk include:

  • Children under 5 years of age, especially infants

  • Older people over 65 years of age

  • People with poor access to hygiene facilities

  • People who live or spend time in crowded conditions

  • People with weak immune systems or chronic illnesses.

How is it spread?

GAS infection can be spread after contact with an infected person as the bacteria is present in their saliva and nasal discharge. This means sneezing, coughing, and any physical contact (such as shaking hands) with an infected person can spread the bacteria. Impetigo, which is caused by the GAS bacteria, is highly contagious and contact with any infected people should be avoided.

In rare cases, GAS infection can also be contracted from contaminated foods such as milk and milk products, and eggs.

Diagnosis of pharyngitis and scarlet fever involves the identification of the bacteria through a throat swab. Blood tests may also be required. For impetigo, a swab of the blisters or crust of sores is taken and examined for the presence of bacteria.

To minimise the risk of GAS infection spreading, it's important to maintain good hygiene in order to decrease the spread of bacteria. This includes washing hands thoroughly with soap, especially after sneezing or coughing, and ensuring all commonly used surfaces (such as sinks, taps, and door handles) are kept clean.

Signs and symptoms

The signs and symptoms of GAS infection depend on where it develops in the body:

Pharyngitis (or streptococcal sore throat)

  • A sore, red throat with thick pus-like fluid around the tonsils

  • Fever and chills

  • Enlarged and tender lymph nodes in and around the neck

  • Vomiting and abdominal complaints.

Scarlet fever

  • Inflammation of the throat

  • A pink-red rash spreading across the abdomen, side of the chest and in the skin folds. The rash may feel like sandpaper when touched

  • A bright red tongue (known as ‘strawberry tongue’)

  • Paleness around the mouth.

Impetigo (or school sores)

  • Blisters, typically around the nose and mouth and the legs

  • Fever and swollen lymph nodes in severe cases.

Rheumatic fever

  • Sore throat that usually starts several weeks after the initial infection

  • Fatigue

  • Muscle aches and joint pain

  • Skin rash.

How to treat group A streptococcus disease

A course of antibiotics is the standard treatment for GAS infection and the duration will depend on the site of infection. Antibiotics that may be prescribed include:

  • Penicillin

  • A cephalosporin or macrolide antibiotic if the patient is allergic to penicillin

  • Antibiotic ointments for impetigo.

If a GAS infection isn't treated, the infectious period can last anywhere between 10 to 21 days, and an untreated infection with a pus-filled discharge can remain infectious for days. As such it is important to complete any course of antibiotics prescribed.


If you have any questions or need extra support, we're here to help you anytime in any language. Simply start a chat with us via the home screen of the Sonder app.

Information sourced from: ABC, Better Health, and Health Direct

Image credit: golovianko at AdobeStock

All content is created and published for informational purposes only. It is not intended to be a substitute for professional advice. Always seek the guidance of a qualified health professional.

Did this answer your question?