Group A ß-haemolytic streptococcus (also known as Streptococcus pyogenes) is a gram positive bacterium that causes a variety of pathological conditions and complications such as throat and skin infections, acute glomerulonephritis, sepsis and rheumatic heart disease.

Pharyngitis is commonly caused by viral infections and, more rarely, by bacterial infections, for which antibiotic therapy is required.

Strep A is a common bacteria (germ). It usually causes mild illness such as sore throats and skin infections. In rare cases, these bacteria can cause a severe and life-threatening illness called invasive group A streptococcal disease (iGAS). Strep A is spread by close contact and can be passed on through coughs and sneezes, or from a wound.                         

A strep A test is often used to find out if a sore throat and other symptoms are being caused by the bacterium or more commonly by a viral infection. Strep throat needs to be treated with antibiotics to prevent complications.

Between September 2022 and June 2023, there were 3,729 cases of iGAS recorded in England. A large increase of scarlet fever was recorded with 58,972 cases reported in England for the same period.