Streptococcal screen

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

  • Alternative Names
    • Rapid strep test

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

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

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

  • Why the Test is Performed
    • 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
  • Normal Results
    • 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.

  • What Abnormal Results Mean
    • 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.

  • Risks
    • There are no risks.

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

  • References
    • 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.

      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: Bope ET, Kellerman RD, eds. Conn's Current Therapy 2016. Philadelphia, PA: Elsevier; 2016:section 1.