Strep Throat Test
- Also Known As:
- Throat Culture
- Rapid Strep Test
- Rapid Antigen Detection Test (RADT)
- Streptococcal Screen
- Group A Streptococcus (GAS)
- Streptococcus (Group A) Rapid by NAAT
- Formal Name:
- Group A Beta Hemolytic Streptococcus Culture|Rapid Antigen Group A Streptococcus Test

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.At a Glance
Why Get Tested?
To determine if your sore throat is strep throat, an infection caused by group A streptococcus (GAS) bacteria
When To Get Tested?
When you have a sore throat that starts quickly and lasts more than a week and/or you have other symptoms, such as a fever of 101° F or higher or reddened throat and/or tonsils with white or yellow patches or streaks
Sample Required?
A health care practitioner uses a tongue depressor to hold down your tongue and then inserts a swab into your mouth and rubs it against the back of your throat and tonsils. The swab may be used to do a rapid strep test in a doctor’s office or clinic, or it may be sent to a laboratory. A second swab may be collected along with the first one. This extra sample may be used to perform a throat culture as a follow-up test, when necessary.
Test Preparation Needed?
No test preparation is needed. The test should be performed before antibiotics are prescribed.
What is being tested?
The bacteria Streptococcus pyogenes, also known as group A beta-hemolytic streptococcus or group A strep (GAS), causes strep throat, the most common bacterial cause of inflammation and soreness of the back of the throat (pharyngitis). Strep tests include rapid strep tests and throat cultures that detect these bacteria in a sample taken from the back of your throat.
While most sore throats are caused by a virus and will resolve without treatment within a few days, some people with sore throats have strep throat. Strep throat is most common in children and teens ages 5 to 15 years old. It is important to diagnose and treat strep infections promptly with antibiotics because they are very contagious and complications can develop.
- Strep throat can easily spread when an infected person coughs or sneezes and other people come into contact with the droplets or mucus. Touching your face, eyes or mouth after touching something that has these droplets on it can spread the infection. The best way to avoid getting strep throat is to wash your hands thoroughly and often and avoid sharing items like utensils or cups. If you have a sore throat, you should wash your hands often and cover your mouth with a tissue or sleeve when coughing and sneezing.
- If strep throat is not diagnosed and treated, complications may develop, especially in children. These complications may include rheumatic fever, which can damage the heart, and glomerulonephritis, which affects the kidneys. Because strep infections are routinely diagnosed and treated, these complications are rare in the United States now, but they do still occur.
A rapid strep test and/or a throat culture is used to diagnose group A strep as the cause of symptoms so your health care practitioner can prescribe the proper antibiotics for treatment.
Common Questions
View Sources
Sources Used in Current Review
(Updated September 7, 2018) Kahn, Z. Group A Streptococcal Infections. Available online at http://emedicine.medscape.com/article/228936-overview. Accessed August 2020.
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(Content Review: October 2017) Group A Streptococcal Disease. ARUP Consult®. Available online at https://arupconsult.com/content/streptococcal-disease-group. Accessed September 2020.
(September 1, 2018) Dithi Banerjee, PhD, and Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA. The Evolution of Group A Streptococcus Pharyngitis Testing. Clinical Laboratory News. Available online at https://www.aacc.org/cln/articles/2018/september/the-evolution-of-group-a-streptococcus-pharyngitis-testing. Accessed September 2020.
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