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.
