Streptococcal screen: MedlinePlus Medical Encyclopedia

P A streptococcal screen is a test to detect group A streptococcus. This bacteria is the most common cause of strep throat.

T How the Test is Performed
P The test requires a throat swab. The swab is tested to identify group A streptococcus. It takes about 7 minutes to get the results.

T How to Prepare for the Test
P There is no special preparation. Tell your health care provider if you are taking antibiotics, or have recently taken them.

T How the Test will Feel
P The back of your throat will be swabbed in the area of your tonsils. This may make you gag.

T Why the Test is Performed
P Your provider may recommend this test if you have signs of strep throat, which include:
- Fever
- Sore throat
- Tender and swollen glands at the front of your neck
- White or yellow spots on your tonsils

T Normal Results
P A negative strep screen most often means group A streptococcus is not present. It is unlikely that you have strep throat.
P If your provider still thinks that you may have strep throat, a throat culture will be done.

T What Abnormal Results Mean
P A positive strep screen most often means group A streptococcus is present, and confirms that you have strep throat.
P Sometimes, the test may be positive even if you do not have strep. This is called a false-positive result.

T Risks
P There are no risks.

T Considerations
P This test screens for the group A streptococcus bacteria only. It will not detect other causes of sore throat.

T Alternative Names
P Rapid strep test

T Images
- Throat anatomy
- Throat swabs

T References
P Flores AR, Caserta MT. Pharyngitis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 59.
P 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.
P 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.
P Weber R. Pharyngitis. In: Bope ET, Kellerman RD, eds. Conn's Current Therapy 2016. Philadelphia, PA: Elsevier; 2016:section 1.

T Review Date 3/13/2016
P Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

