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Group A Streptococcus Infections

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Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

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Group A streptococcal infections facts

• Group A streptococci (GAS) are gram-positive coccal-shaped bacteria that produce beta-hemolysis (lysis of red blood cells producing clear or transparent areas) and appear as usually as a chain of two or more bacteria.



• Group A Streptococcus (GAS) organisms are usually spread by direct human-to-human transfer. Occasionally, they can be spread by droplets or by a person touching items recently handled by an infected individual.



• GAS can cause a wide range of diseases, but most notably, strep throat; other diseases (or complications) include scarlet fever, rheumatic fever, kidney damage, skin and wound infections and occasionally, necrotizing fasciitis and toxic shock syndrome.



• Symptoms and signs of GAS disease are variable and are related to the body area that is undergoing the infection; for example, sore throat, throat erythema, and swollen lymph nodes in strep throat to low blood pressure and organ failure in toxic shock syndrome.



• Early signs and symptoms of necrotizing fasciitis include fever, severe pain and swelling, and erythema (redness) at the wound site or site where GAS organisms entered the body; later signs and symptoms include fluid discharge from the infected tissue, skin loss and low blood pressure



• Early symptoms of toxic shock syndrome are nonspecific, often begin with flu-like symptoms of mild fever and malaise, then often suddenly advances with symptoms of high fever, nausea, vomiting, diarrhea, skin rash, and a low blood pressure with possible progression to include confusion, headaches, seizures, and skin loss from the palms of the hands and from the soles of the feet.



• Diagnosis of GAS is made by culturing the bacteria and having the laboratory identify the bacteria by metabolic functions and immunologic tests; rapid tests are based on immunological recognition of GAS antigens taken from the patient by swabbing the throat.



• Although oral antibiotics (many types) are effective in treating milder forms of GAS infections, more serious forms of GAS such as invasive GAS disease usually require multiple antibiotics administered IV; in addition, some patients may require surgery to remove dead and dying tissue.



• The prognosis (outcome) of GAS infections, especially mild infections, is usually good to excellent. However, as the disease progresses from moderate to severe, the prognosis decreases from good to poor; early effective treatment may improve the prognosis.



• Prevention of GAS infections is possible by attention to good hygiene such as hand washing and avoiding eating or drinking from the same containers used by other people and avoiding direct and indirect (for example, droplet or particle contamination of clothing) contact with a infected individual; early treatment of GAS infections can reduce or avoid the progression to more severe disease.



• Although research is ongoing, there is no commercially available vaccine to prevent GAS infections.