Streptococcus A (Strep A)


Group A Streptococcus (GAS) – also known as Streptococcus pyogenes – are bacteria  commonly found on the skin or in the throat, where they can live without causing problems. Under some circumstances, however, these bacteria can cause disease.

GAS bacteria can cause a wide variety of skin, soft tissue and respiratory tract infections ranging in severity from mild to life-threatening. These include:

The most common presentations of GAS infection are a mild sore throat ('strep throat') and skin/soft tissue infections such as impetigo and cellulitis.

If you have a sore throat or tonsillitis some pharmacies are offering a Test and Treat service for some types of conditions. You can search for a participating pharmacy here.

In rare cases, patients may go on to develop post-streptococcal complications, such as:

However, GAS can cause more serious invasive infections (referred to as iGAS infections) such as bacteraemia (an infection of the bloodstream), necrotising fasciitis (a severe infection involving death of areas of soft tissue below the skin) and streptococcal toxic shock syndrome (rapidly progressive symptoms with low blood pressure and multi-organ failure).

iGAS infections are most common in the elderly, the very young or people with an underlying risk factor such as injecting drug use, alcoholism, immunosuppression or cancer.

GAS is spread by close contact between individuals, through respiratory droplets and direct skin contact.

It can also be transmitted environmentally, through contact with contaminated objects, such as towels or bedding or ingestion of food inoculated by a carrier.

Things you can do yourself

The best thing that parents can do is to provide the care they would usually provide for a child with cold and flu like symptoms, and to familiarise themselves with the symptoms of scarlet fever and iGAS as a precaution.

You can find more information about looking after a sick child here.

Symptoms of scarlet fever

The symptoms of scarlet fever include a sore throat, headache, fever, nausea and vomiting.  This is followed by a fine red rash, which typically first appears on the chest and stomach, rapidly spreading to other parts of the body. Older children may not have the rash.

On more darkly pigmented skin, the scarlet rash may be harder to spot, but it should feel like 'sandpaper'.  The face can be flushed red but pale around the mouth.

Find out more about scarlet fever

Symptoms of iGAS

  • Fever (a high temperature above 38°C)
  • Severe muscle aches
  • Localised muscle tenderness
  • Redness at the site of a wound

As a parent, if you feel that your child seems seriously unwell, you should trust your own judgement. Contact your GP or NHS 111 Wales if:

  • your child is getting worse
  • your child is feeding or eating much less than normal
  • your child has had a dry nappy for 12 hours or more or shows other signs of dehydration
  • your baby is under 3 months and has a temperature of 38°C, or is older than 3 months and has a temperature of 39°C or higher
  • your baby feels hotter than usual when you touch their back or chest, or feels sweaty
  • your child is very tired or irritable

Call 999 or go to A&E if:

  • your child is having difficulty breathing – you may notice grunting noises or their tummy sucking under their ribs
  • there are pauses when your child breathes
  • your child’s skin, tongue or lips are blue
  • your child is floppy and will not wake up or stay awake

Good hand and respiratory hygiene are important for stopping the spread of many bugs. By teaching your child how to wash their hands properly with soap for 20 seconds, using a tissue to catch coughs and sneezes, and keeping away from others when feeling unwell, they will be able to reduce the risk of picking up or spreading infections.

The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website
Last Updated: 13/12/2022 14:41:35