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.
However, 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. However, 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.
Therefore, some experts feel that it is better to have a throat
culture than a rapid strep test since the culture imposes a 1- to 2-day waiting
period before the person can begin taking antibiotics (if needed).