Group A Streptococcus (GAS) is part of the streptococcus group of bacteria, which includes over 200 strains, with Streptococcus pyogenes being the most common. Infection with GAS can cause a range of symptoms, including sore throats (pharyngitis), scarlet fever, or impetigo, and some strains can also cause serious conditions such as toxic shock syndrome. Diagnosis is typically by culture or rapid antigen detection assays; however, molecular detection is becoming more widely available.