Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Group A streptococcal infection

6-minute read

Key facts

  • Group A streptococcus (GAS) is a type of bacteria often found in the throat and on the skin.
  • It can cause strep throat, scarlet fever, impetigo, cellulitis and other rare but severe health conditions.
  • The best way to prevent group A streptococcal infections is to follow good hygiene practices and stay home when you're sick.
  • GAS infections can be treated with antibiotics.

What is group A streptococcus?

Group A streptococcus (GAS) is a type of bacteria. It is also called:

  • group A strep
  • strep A
  • type A streptococcal
  • streptococcus pyogenes

GAS is often found in the throat and on the skin of people who do not have any symptoms.

Healthy people can be carriers of GAS without having any symptoms or becoming unwell.

What is group A streptococcal infection?

GAS can cause infections in some people, making them unwell. Group A streptococcal infections can cause:

Invasive group A streptococcal (iGAS) infections

In rare cases the bacteria can cause a severe, life-threatening infection known as invasive group A streptococcal (iGAS) infection. Types of iGAS are:

People with iGAS infections need to be treated in hospital.

What are the symptoms of group A streptococcal infection?

The symptoms of group A streptococcal infection depend on where the infection is in your body. One common symptom of GAS infection is fever.

Early symptoms of iGAS infections can also include fever and:

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes group A streptococcal infection?

If you are in close contact with someone with group A streptococcal bacteria, you may become infected if you:

  • breathe in droplets from their coughs or sneezes
  • touch something with droplets on it and then touch your mouth or nose
  • touch them or have contact with infected skin sores
  • kiss them

Anyone can get a group A streptococcal infection, but people who are most at risk are:

  • children under 5 years of age, especially newborn babies
  • people who are pregnant or have recently given birth
  • older people
  • people who live with someone who has a GAS infection
  • people with poor access to hygiene facilities
  • people who live or spend time in crowded conditions
  • people with weak immune systems or chronic illnesses (such as diabetes or heart disease)

Children are more likely to become infected because they tend to be less aware of hygiene than adults. They also generally spend more time in crowded environments, such as schools, and play in close physical contact.

When should I see my doctor?

Visit your doctor if you have a severe sore throat, skin sores or a wound that is not getting better.

If you think you or someone you care for has a group A streptococcal infection, it is important to see a doctor as soon as possible.

The infection can spread through the body and can become serious if not promptly treated with antibiotics.

A person with iGAS can become very sick within 12 to 24 hours, so it's important to seek medical care promptly.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

How is group A streptococcal infection diagnosed?

Your doctor will ask about your symptoms and do a physical examination.

Depending on your symptoms and the type of infection you have, your doctor will recommend tests to check if you have a group A streptococcal infection. These may include:

  • a swab of your throat or a skin sore
  • blood tests
  • a sample of other body fluid
  • x-rays or other imaging tests

How is a group A streptococcal infection treated?

Group A streptococcal infections are treated with antibiotics.

Your doctor will work out which antibiotic is best, depending on where your infection is located and how serious it is.

People with invasive group A streptococcal (iGAS) infection need to be treated in hospital.

Can group A streptococcal infection be prevented?

You can help prevent group A streptococcal infections by maintaining good hygiene. To decrease the spread of bacteria, wash your hands often, especially after sneezing or coughing and before preparing, serving or eating food.

Ensure surfaces (such as bathroom sinks, taps and door handles) as well as clothes and bedlinen are kept clean to protect all the members of your household.

If you or your child have strep throat or another form of GAS infection, you should stay home from pre-school, school or work for at least 24 hours after starting antibiotic treatment.

Antibiotics for close contacts of people with iGAS infection

Talk to your doctor if you have been in close contact with someone with an invasive group A streptococcal infection.

Your doctor may recommend you take a course of antibiotics to reduce your risk of infection.

Complications of group A streptococcal disease

In some people, a group A streptococcal infection can lead to serious complications. These can include:

  • Rheumatic fever, which can affect your heart, joints, brain and skin.
  • Post-streptococcal glomerulonephritis (which affects your kidneys).
  • Severe scarring or limb loss from necrotising fasciitis or toxic shock syndrome.

Resources and support

If you are concerned about GAS infection you can call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: November 2023


Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Streptococcal infection - group A - Better Health Channel

Streptococcal infection ? group A can cause sore throats (pharyngitis), scarlet fever or impetigo (school sores).

Read more on Better Health Channel website

Impetigo - ACD A-Z of Skin

Impetigo Also known as…School Sores What is Impetigo? Impetigo is an infection of the skin that can be passed from person to person

Read more on Australasian College of Dermatologists website

Strep throat testing | Pathology Tests Explained

The test identifies Streptococcus pyogenes, known as Group A streptococci, which are bacteria that infect the back of the throat and cause the common

Read more on Pathology Tests Explained website

Impetigo (school sores) fact sheet - Fact sheets

Impetigo is a common skin infection that mostly affects children. It is treated with antibiotics. Practising good hygiene can help to stop the spread of impetigo.

Read more on NSW Health website

Impetigo - school sores - Better Health Channel

Impetigo, or school sores, is a highly contagious skin infection that commonly affects school-aged children.

Read more on Better Health Channel website

Impetigo (school sores)

Impetigo is a contagious skin infection caused by Staphylococcus or Streptococcus bacteria.

Read more on WA Health website

Impetigo or school sores: kids & teens | Raising Children Network

Impetigo or school sores is when sores on your child’s skin are infected by bacteria. It’s very contagious. Your child probably needs antibiotic treatment.

Read more on raisingchildren.net.au website

Invasive Group A Streptococcal (iGAS) disease | Health and wellbeing | Queensland Government

Invasive Group A Streptococcal (iGAS) disease

Read more on Queensland Health website

Group A strep in pregnancy

Group A streptococcus (GAS) is a bacteria that causes both mild and severe disease in pregnancy. Learn more on symptoms and when to see your doctor.

Read more on Pregnancy, Birth & Baby website

Group A streptococcal | NT.GOV.AU

Invasive group A streptococcal, who is at risk, treatment and prevention.

Read more on NT Health website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Queensland Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.