Infectious Disease Epidemiology Program

Airborne and Direct Contact Diseases - Group A Strep

Group A Streptococcus is a bacterium often found in the throat and on the skin. People may carry group A streptococci in the throat or on the skin and have no symptoms of illness. Most GAS infections are relatively mild illnesses such as "strep throat," or impetigo. Occasionally these bacteria can cause severe and even life-threatening diseases.

Severe, sometimes life-threatening, GAS disease may occur when bacteria get into parts of the body where bacteria usually are not found, such as the blood, muscle, or the lungs. These infections are termed "invasive GAS disease." Two of the most severe, but least common, forms of invasive GAS disease are necrotizing fasciitis and streptococcal toxic shock syndrome. Necrotizing fasciitis (occasionally described by the media as "the flesh-eating bacteria") is a rapidly progressive disease which destroys muscles, fat, and skin tissue. Streptococcal toxic shock syndrome (STSS) results in a rapid drop in blood pressure and organs (e.g., kidney, liver, lungs) to fail. STSS is not the same as the "toxic shock syndrome" due to the bacteria Staphylococcus aureus which has been associated with tampon usage. While 10%-15% of patients with invasive group A streptococcal disease die from their infection, approximately 25% of patients with necrotizing fasciitis and more than 35% with STSS die.