Rapid Test Versus Throat Culture for Strep Throat

If you need to be tested for strep throat, the choice between a rapid strep test and a throat culture may not be clear. It may be helpful to discuss with your doctor the advantages and disadvantages of each.

Rapid strep test

Results from a rapid strep test are available within 10 to 15 minutes. Results from a throat culture may take 1 to 2 days. The faster speed of the results from rapid strep testing gives it some advantages over throat culture when the results of the rapid test are positive:

• Antibiotic treatment can be started immediately. You do not have to wait 1 to 2 days for test results from a throat culture.
• You are contagious for a shorter period of time and thus able to return to school or work sooner.

But the rapid strep test is not as accurate as a throat culture. The rapid strep test can give negative results even when strep bacteria are present. If the results of a rapid strep test are negative, many doctors may recommend doing a throat culture to confirm that you do not have strep throat.

• Having a second test costs more than just having a throat culture at the beginning.
• You will still have the 1- to 2-day waiting period for results.

Throat culture

If you have a throat culture instead of a rapid strep test, you will need only one test because the results of a throat culture are usually very accurate. If the results are negative, you will not need further testing or antibiotics. If the results are positive, you can start antibiotic treatment immediately. But you could have started antibiotic treatment a day or two earlier if you had a rapid strep test.

There is also some debate over when to begin treatment. Although immediate treatment decreases the time the person is able to pass on the infection, it may reduce the body's natural defense (immune) response to the infection. If 1 to 2 days pass before beginning treatment, the body has a chance to build up its disease-fighting mechanism. Antibiotic treatment will still help prevent rheumatic fever when started up to 9 days after symptoms start.¹

So some experts feel that it is better to have a throat culture than a rapid strep test because the culture imposes a 1- to 2-day waiting period before the person begins taking antibiotics (if they are needed).

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