Group A Streptococcal (GAS) Disease FAQs (strep throat, necrotizing fasciitis, impetigo)
Adapted from the Centers for Disease Control and Prevention. For more information or FAQs in Spanish, visit their website.
What is group A streptococcus (GAS)?
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. On rare occasions, these bacteria can cause other severe and even life-threatening diseases
How are group A streptococci spread?These bacteria are spread through direct contact with mucus from the nose or throat of persons who are infected or through contact with infected wounds or sores on the skin. Ill persons, such as those who have strep throat or skin infections, are most likely to spread the infection. Persons who carry the bacteria but have no symptoms are much less contagious. Treating an infected person with an antibiotic for 24 hours or longer generally eliminates their ability to spread the bacteria. However, it is important to complete the entire course of antibiotics as prescribed. It is not likely that household items like plates, cups, or toys spread these bacteria.
What kind of illnesses are caused by group A streptococcal infection?Infection with GAS can result in a range of symptoms:
- No illness
- Mild illness (strep throat or a skin infection such as impetigo)
- Severe illness (necrotizing faciitis, streptococcal toxic shock syndrome)
How common is invasive group A streptococcal disease?
About 9,400 cases of invasive GAS disease occurred in the United States in 1999. Of these, about 300 were STSS and 600 were necrotizing fasciitis. In contrast, there are several million cases of strep throat and impetigo each year.
Why does invasive group A streptococcal disease occur?
Invasive GAS infections occur when the bacteria get past the defenses of the person who is infected. This may occur when a person has sores or other breaks in the skin that allow the bacteria to get into the tissue, or when the person’s ability to fight off the infection is decreased because of chronic illness or an illness that affects the immune system. Also, some virulent strains of GAS are more likely to cause severe disease than others.
Who is most at risk of getting invasive group A streptococcal disease?Few people who come in contact with GAS will develop invasive GAS disease. Most people will have a throat or skin infection, and some may have no symptoms at all. Although healthy people can get invasive GAS disease, people with chronic illnesses like cancer, diabetes, and kidney dialysis, and those who use medications such as steroids have a higher risk.
What are the early signs and symptoms of necrotizing fasciitis and streptococcal toxic shock syndrome?Early signs and symptoms of necrotizing fasciitis;
- Severe pain and swelling
- Redness at the wound site
- a flat red rash over large areas of the body