Strep Throat Definition
Strep throat is a contagious disease caused by infection with streptococcal bacteria, which causes inflammation and swelling of the mucous membranes lining the back of the throat and the tonsils. It is a common cause of sore throat in school-aged children and teens, and its prompt diagnosis and treatment is important to prevent any potential complications.
Strep Throat Causes
Strep throat is caused by infection with Group A Streptococcus (GAS) bacteria, specifically Streptococcus pyogenes. The streptococcal infection invades the pharyngeal tissue and causes a localized inflammatory reaction of the throat and tonsils. These bacterial organisms are often found in the throat or on the skin, and are responsible for other illnesses as well, such as impetigo (a skin infection). Some individuals may carry Group A Streptococcus in the throat or on the skin and not exhibit any signs or symptoms of disease (asymptomatic).
Strep throat is most common in school-aged children and teens, with a peak incidence between 5 to 15 years of age. It is estimated that approximately 15% to 40% of cases of sore throat in this age group are caused by Streptococcus spp bacteria. Adults may also develop strep throat, though less commonly (accounts for approximately 5% to 10% of cases of sore throat). Strep throat most commonly occurs between late fall and early spring. It is more widespread during the school year when groups of students are present within an enclosed space.
Though strep throat is the most common bacterial cause of sore throat, it is important to note that most cases of sore throat are in fact due to a viral infection (caused by a virus). A viral sore throat typically improves on its own and neither requires nor responds to treatment with antibiotics. However, the identification of strep throat is important to prevent the potential complications associated with this illness.
Last Reviewed 11/17/2017
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