A streptococcal screen is a test to detect group A streptococcus. This type of bacteria is the most common cause of strep throat.
The test requires a throat swab. The swab is tested to identify group A streptococcus. It takes about 7 minutes to get the results.
There is no special preparation. Tell your health care provider if you are taking antibiotics, or have recently taken them.
The back of your throat will be swabbed in the area of your tonsils. This may make you gag.
Your provider may recommend this test if you have signs of strep throat, which include:
- Sore throat
- Tender and swollen glands at the front of your neck
- White or yellow spots on your tonsils
A negative strep screen most often means group A streptococcus is not present. It is unlikely that you have strep throat.
If your provider still thinks that you may have strep throat, a throat culture will be done in children and adolescents.
A positive strep screen most often means group A streptococcus is present, and confirms that you have strep throat.
Sometimes, the test may be positive even if you do not have strep. This is called a false-positive result.
This test screens for the group A streptococcus bacteria only. It will not detect other causes of sore throat.
Flores AR, Caserta MT. Pharyngitis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 59.
Nussenbaum B, Bradford CR. Pharyngitis in adults. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 6th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 9.
Shulman ST. Group A streptococcus. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 183.
Weber R. Pharyngitis. In: Kellerman RD, Bope ET, eds. Conn's Current Therapy 2018. Philadelphia, PA: Elsevier Saunders; 2018;50-52.