Key facts

• Strep A is a common bacteria that can cause various infections
• Many people carry strep A without any problems
• Most infections are mild and easily treated with antibiotics
• Strep A can be spread through close contact with an infected person
• Occasionally, serious infections known as invasive group A strep (iGAS) can occur
• Good hygiene practices can help prevent the spread of infection

Overview

Strep A, also known as Group A Streptococcus (GAS), is a type of bacteria that can cause a variety of infections, including scarlet fever and the skin infection impetigo. These infections can range from minor to serious. Strep A bacteria can colonise the throat, skin and anogenital tract.

Although Strep A infections are more common in children, adults can also contract them. Most infections are not serious and can be treated with antibiotics. However, in rare cases, the infection can lead to serious problems known as invasive group A strep (iGAS), which requires hospital treatment.

Signs and symptoms

Common symptoms of a Strep A infection can include flu-like symptoms such as high temperature, swollen glands or an aching body.

Other symptoms include:

• White spots at the back of their throat
• Very large red tonsils
• Tender lumps under their chin

Dangers and complications

While most Strep A infections are mild, some can be very serious. Invasive group A strep (iGAS) is a serious infection that occurs when the bacteria invade the blood or muscle. This condition requires hospital treatment with antibiotics.

Two of the most severe complications are necrotising fasciitis and streptococcal toxic shock syndrome. Long-term health issues related to group A strep bacteria can include post-streptococcal glomerulonephritis, chronic kidney disease and rheumatic fever, which are thought to be caused by an abnormal immune response to infection. These complications are rare,however.

Transmission

Strep A infections are highly contagious and are typically spread through close contact with an infected individual. The bacteria can be passed on through respiratory droplets produced by coughing and sneezing, or through direct contact with infected skin or sores.

People can be carriers of the bacteria without showing symptoms, but they can still transmit it to others.

Treatment

Most Strep A infections can be easily treated with antibiotics. It is important to seek medical advice if you suspect a Strep A infection to get the correct treatment. If you or your child has a Strep A infection, it is important to stay away from nursery, school or work for 24 hours after starting antibiotics to avoid spreading the infection.

Serious Strep A infections, such as iGAS, require hospital treatment with antibiotics.

Prevention

To reduce the chance of catching or spreading a Strep A infection, it is recommended to avoid close contact with infected individuals. Other preventive measures include washing hands frequently with soap and water, covering your mouth and nose when you cough or sneeze and disposing of used tissues quickly.

It is also advisable to treat any Strep A infections promptly with antibiotics, as this can help prevent the spread of the bacteria.

History

Strep A infections have been around for many years and in the 19th century scarlet fever and rheumatic fever were common causes of mortality, particularly among children. The advent of antibiotics and improved living conditions meant that the number of large outbreaks and the high death rates began to fall.

However, the threat of the infection has not gone away and between 2022 and 2023 there were a higher than expected number of cases and deaths in the UK thought to be due to increased mixing after the easing of Covid restrictions.

Useful links

nhs.uk/conditions/strep-a/

who.int/diseases/streptococcus-pyrogenes

cdc.gov/group-a-strep

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