The Facts

Strep throat is the most common of bacterial infections, accounting for about 15% of all sore throats that get diagnosed in the doctor's office. It's most common in children, but many adults get strep throat too. It's called "strep" throat because the bacterium that causes it belongs to the class known as group A streptococcus. The initials GAS are sometimes used, and doctors may talk about a GAS throat infection.

Sore throat is one of the leading complaints that brings people to the doctor's office, and almost 50% of sore throats are treated with antibiotics in the United States. In fact, fewer than half of the people given antibiotics actually have bacterial infections. Most of the rest have viral infections that are untouched by antibiotics. Antibiotics can be bad for you, killing harmless bacteria that may be keeping dangerous bacteria out of your intestines. A wise parent will learn to distinguish viral and bacteria infections, to avoid unnecessary antibiotic use. And a wise patient will not press a doctor for antibiotics when the doctor says they aren't needed.

Causes

Streptococci are everywhere. About 20% of us have them on our skin, and 10% of children have them in their throats at any given time. They don't always cause disease; however, streptococci are infectious. They are passed around in the same way as cold viruses, by coughing, sneezing, or getting mucus or saliva on the hand, then touching other people. They are less contagious than a cold virus, however.

Smoking and heavy drinking, which can damage the lining of the throat, increase the risk of bacterial infection. Frequent heartburn can also encourage throat irritation if the digestive acids rise as high as the throat. People with weak immune systems from HIV/AIDS, diabetes, cancer treatment, or corticosteroid drug use are also at higher risk.

The easiest place to catch strep throat is in a hospital. Not only are there more vulnerable people around, but hospital workers and inpatients are also more likely than average to carry group A strep. Children who attend daycare, as well as daycare workers, are also at higher risk of catching bacterial infections.