Strep throat is an infection of the throat caused by group A streptococci bacteria. These bacteria can cause inflammation and infection in a variety of areas throughout the body, including the respiratory system, skin and vital organs. In addition, damage to the heart valves (in rheumatic fever) and kidneys (glomerulonephritis) sometimes occurs.

A strep throat infection can be transmitted by kissing, coughing or sneezing. Symptoms usually appear within five days of exposure to the bacteria and include a sore throat, fever, swollen neck glands and inflamed tonsils. Symptoms tend to begin suddenly and are usually more severe than those experienced with viral infections. Coughing and a runny nose are not signs of strep throat.

Most cases of strep throat occur in children between the ages of 5 and 15. People who spend time in crowded environments (e.g., work, daycare facilities, school) or who live in northern areas of the United States face an increased risk of developing strep throat.

People who suspect they have strep throat are urged to consult a physician. A physical examination and medical history may be performed, although the only way to identify the presence of strep throat is with a throat culture and/or rapid strep test. The rapid stress test is similar to a throat culture, but with much faster results.

Antibiotics are used to treat strep throat. This kills the bacteria that causes infection, limits the spread of infection to others and prevents serious medical conditions that may occur if an untreated infection spreads throughout the body. People remain contagious for at least a day after beginning treatment.