Patient Basics: Rapid Strep Test

Originally published by Harvard Health.

What is the test?

A throat infection with streptococcus bacteria (called strep throat) needs to be treated with an antibiotic. A test is commonly used to find out whether streptococcus bacteria are present on your throat surface. The traditional test for a strep throat has been a throat culture, which takes two to three days to produce results. Several different types of rapid strep tests, however, can produce results within minutes to hours. A rapid strep test can only detect the presence of Group A strep, the one most likely to cause serious throat infections; it does not detect other kinds of strep or other bacteria.

How do I prepare for the test?

No preparation is necessary.

What happens when the test is performed?

A cotton swab is rubbed against the back of your throat to gather a sample of mucus. This takes only a second or two and makes some people feel a brief gagging or choking sensation. The mucus sample is then tested for a protein that comes from the strep bacteria.

What risks are there from the test?

There are no risks.

Must I do anything special after the test is over?

No.

How long is it before the result of the test is known?

Results may be available in minutes to a few hours. Often the doctor will ask you to wait in the office until the result is back.