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Group A Streptococcus Frequently Asked Questions

Q: What is group A Streptococcus?

A: Group A streptococcus (group A strep) are bacteria that can cause a wide range of infections. People may also carry group A strep in the throat or on the skin and have no symptoms of illness. Most group A strep infections are relatively mild illnesses, such as "strep throat" or impetigo (a skin infection). Occasionally these bacteria can cause serious and even life-threatening diseases.

Q: How are group A strep spread?

A: These bacteria are spread through direct contact with mucus from the nose or throat of people who are sick with a group A strep infection or through contact with infected wounds or sores on the skin. The bacteria may also be spread through contact with people without symptoms but who carry the bacteria in their throat or on their skin. Ill people, such as those who have strep throat or skin infections, are most likely to spread the infection. People 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 prevents the spread of the bacteria to others. However, it is important to complete the entire course of antibiotics as prescribed. It is not likely that household items, like toys, spread these bacteria. However, it is possible to spread these bacteria by drinking from the same glass or eating from the same plate as someone who is ill with a group A strep infection like strep throat.

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Q: What kind of illnesses are caused by group A strep?

A: Infection with group A strep can result in a range of illnesses:

  • Mild illness such as strep throat or impetigo
  • Serious illness such as pneumonia (lung infection), necrotizing fasciitis, or streptococcal toxic shock syndrome (STSS)

Serious, sometimes life-threatening group A strep disease may occur when these bacteria get into parts of the body where bacteria usually are not found, such as the blood, muscle, or the lungs. These infections are called "invasive group A strep disease." Two of the most serious, but least common, forms of invasive group A strep disease are necrotizing fasciitis and STSS. Necrotizing fasciitis (occasionally described by the media as "the flesh-eating bacteria") rapidly destroys muscles, fat, and skin tissue. STSS causes blood pressure to drop rapidly and organs (e.g., kidney, liver, lungs) to fail. STSS is not the same as the staphylococcal toxic shock syndrome that has been associated with tampon usage. Less serious invasive illnesses caused by group A strep include cellulitis and pneumonia. In the United States, about 1 out of 4 patients with necrotizing fasciitis due to group A strep and approximately 4 out of 10 with STSS die. About 10 to 15 out of 100 patients with any form of invasive group A strep disease die.

Q: How common is invasive group A strep disease?

A: Approximately 9,000 to11,500 cases of invasive group A strep disease occur each year in the United States, resulting in 1,000 to 1,800 deaths annually. Most of these cases are less serious invasive infections, like cellulitis. STSS and necrotizing fasciitis are each responsible for an average of about 6 to 7 out of 100 of these invasive cases. In contrast, there are several million cases of non-invasive group A strep infections, like strep throat and impetigo, each year.

Q: Who is most at risk of getting invasive group A strep disease?

A: Few people who come in contact with group A strep will develop invasive group A strep disease. Most people will have a throat or skin infection, and some may have no symptoms at all. Although healthy people can get invasive group A strep disease, people with chronic illnesses like cancer, diabetes, and chronic heart or lung disease, and those who use medicines, such as steroids, have an increased risk. People with skin lesions (such as cuts, chickenpox, or surgical wounds), the elderly, and adults with a history of alcohol abuse or injection drug use also have an increased risk for disease.

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Q: What are the early signs and symptoms of necrotizing fasciitis and streptococcal toxic shock syndrome?

A: Early signs and symptoms of necrotizing fasciitis include:

  • Severe pain and swelling, often rapidly increasing
  • Fever
  • Redness at a wound site

Early signs and symptoms of STSS include:

  • Sudden onset of generalized or localized severe pain, often in an arm or leg
  • Dizziness
  • Flu-like symptoms such as fever, chills, muscle aches, nausea, vomiting
  • Confusion
  • A flat red rash over large areas of the body (only occurs in 1 out of 10 cases)

Q: How is invasive group A strep disease treated?

A: Group A strep infections can be treated with many different antibiotics (medicines that kill bacteria in the body). For STSS and necrotizing fasciitis, high dose penicillin and clindamycin are recommended. For those with very serious illness, supportive care in an intensive care unit may also be needed. For people with necrotizing fasciitis, early and aggressive surgery is often needed to remove damaged tissue and stop disease spread. Early treatment may reduce the risk of death from invasive group A strep disease. However, even the best medical care does not prevent death in every case.

Q: What can be done to help prevent group A strep infections?

A: The spread of all types of group A strep infection can be reduced by good hand washing, especially after coughing and sneezing and before preparing foods or eating. People with sore throats should be seen by a doctor who can perform tests to find out whether the illness is strep throat. If the test result shows strep throat, the person should stay home from work, school, or day care until 24 hours after taking an antibiotic. All wounds should be kept clean and watched for possible signs of infection such as redness, swelling, drainage, and pain at the wound site. A person with signs of an infected wound, especially if fever occurs, should immediately seek medical care. It is not necessary for all people exposed to someone with an invasive group A strep infection (i.e., necrotizing fasciitis or STSS) to receive antibiotic therapy to prevent infection. However, in some situations, antibiotic therapy may be recommended. That decision should be made after talking with your doctor.

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