Strep throat is a common bacterial infection, accounting for about 15% of all sore throats that get diagnosed in the doctor's office.
It's called "strep" throat because the bacterium that causes it belongs to the class known as group A streptococcus (GAS). Although strep throat can occur any time during the year, late winter and early spring are considered to be peak seasons for strep throat infections.
Sore throat is one of the leading complaints that bring people to the doctor's office, and the majority of adults with sore throats are treated with antibiotics, though fewer than half of the people given antibiotics actually have bacterial infections. Most of the rest have viral infections that are not affected by antibiotics.
When used appropriately, antibiotics are very helpful in fighting infection. However, antibiotics used inappropriately can be bad for you, killing harmless bacteria that may be keeping dangerous bacteria out of your intestines. It is important to learn about appropriate (and unnecessary) antibiotic use, which includes not pressing a doctor for antibiotics when the doctor says they aren't needed.