Strep A

Strep A, also known as Group A Streptococcus or GAS, is a bacteria which causes infections in the skin, soft tissue and respiratory system. The bacteria is commonly found on the skin or in the throat, and can cause infections such as a sore throat (strep throat), Scarlet Fever, Tonsillitis, Pharyngitis, Impetigo and Cellulitis. Invasive Group A Streptococcus, known as iGAS, is a more serious infection, caused when the bacteria enters a part of the body where it is not usually found, such as the lungs or bloodstream. iGAS can cause more severe infections including Necrotising Fasciitis, Necrotising Pneumonia and Streptococcal Toxic Shock Syndrome.

GAS is spread mainly by airborne transmission through coughs and sneezes, close contact with a person with open wounds or sores or from touching or using contaminated objects or items. Some people may be carrying the bacteria, without being unwell, but they are still able to transmit it to others, however, the risk is greater when a person shows symptoms. It is possible for GAS to develop as a secondary infection in someone who is already unwell with a viral illness such as the flu.

The majority of people recover from a GAS infection, but in a small number, iGAS infections can be fatal.

Those at increased risk of developing GAS include anyone who:

  • is aged 5 to 15 years
  • elderly
  • has sores or open wounds
  • has alcoholism or is an injecting drug user
  • is immune-compromised due to an existing health condition
  • lives with or is in close contact with a person who has any type of GAS infection.


Initial signs of GAS are flu-like symptoms including:

  • high temperature
  • sore throat
  • swollen neck glands
  • muscle aches
  • nausea or vomiting
  • a rash on the skin

Some symptoms may not develop until up to 48 hours after other symptoms. Subsequent symptoms and the period when someone is contagious will vary, depending on the infection a person has.

A person is not usually infectious after 24 hours of starting treatment such as antibiotics.

What to do

Symptoms of GAS can be relieved by:

  • resting
  • drinking plenty of fluids, such as water and soft foods
  • taking regular pain relief such as paracetamol or ibuprofen
  • gargling with warm salt water

A GP may prescribe antibiotics for confirmed cases of minor GAS infections. More severe cases may require admission to hospital.

An infection person should stay at home until they are well and not attend nursery, school or work.

A GP or NHS 101 should be contacted for advice if the infected person is getting worse, is dehydrated, or has an extremely high temperature (that is, 38oC or higher if under 2 months, or over 39oC if over 3 months).

999 should be contacted if the infected person is having trouble breathing, their skin, tongue or lips have turned blue, will not wake up, stay awake or are floppy.


It is advisable for a person infected with GAS to isolate and not attend work, school or nursery until they are well. They and anyone who is in contact with them, should practice good hygiene to help prevent transmission of the illness to others, this includes:

  • washing hands using soap and water or an alcohol-based hand rub
  • avoiding touching the eyes, nose or mouth
  • regularly cleaning surfaces and objects that could become contaminated using an anti-bacterial cleaner
  • using a disposable tissue when coughing or sneezing and disposing of the tissue immediately afterwards
  • avoiding close contact with people who are unwell
  • remaining away from others if unwell, until recovered
  • avoiding sharing clothes or linens such as bedding and towels with others

Whilst there is no vaccination against GAS, it is recommended that children and adults are fully vaccinated, so they are protected against other illnesses such as the flu.

Reporting GAS

The local Public Health - Health Protection Team for North and West Northamptonshire work closely with UKHSA (UK Health Security Agency). They use routine surveillance programmes to monitor the spread of infectious diseases and provide support to prevent and control infection in establishments such as hospitals, care homes and schools.

As GAS is a notifiable disease in England, it is important that health professionals inform East Midlands UK Health Security Agency (UKHSA) of any cases for early identification and management of cases to prevent onward transmission of this disease.

Contact details for East Midlands UKHSA
Telephone: 0344 2254 524 (option 1)
Email: [email protected]
These are not constantly monitored out of hours.

Further information

Last updated 25 January 2023