• Conjunctivitis
• Coryza
• Cough
• Diarrhea

Source: Clin. Infect. Dis. 2002;35:113-25

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Rapid Strep Test vs. Throat Culture

A throat culture is considered the “gold standard,” with sensitivity of approximately 95%. However, rapid strep testing has been recently advocated by many societies because:⁹

• Newer assays have adequate sensitivity (90%-95%) and specificity (90%-99%).⁸
• Reduces unnecessary short-term treatment while waiting for cultures.
• Potentially reduces need for callbacks.
• Allows timely initiation of antibiotics, reducing acute morbidity and contagion.
• Has high patient satisfaction despite wait times.

In contrast, the American Academy of Pediatrics (AAP) recommends routine rapid antigen testing and routine culture in all children with suspected strep pharyngitis because of a higher incidence of GABHS infection and the higher sensitivity of a throat culture. What is the “best practice” at this time for my patient? Overall, following a clinical decision rule and/or selective testing to help identify patients who are most likely to benefit from antibiotic treatment appears to be the best course of action.⁸

Antiobiotics for a GABHS Infection

One of the largest reviews on this subject is from the Cochrane database.¹⁰ The review included trials of antibiotic against control with either measures of the typical symptoms (throat soreness, headache, or fever) or suppurative or nonsuppurative complications. Suppurative complications include acute otitis media, acute sinusitis, and quinsy (peritonsillar abscess), while nonsuppurative complications include acute glomerulonephritis and acute rheumatic fever (ARF).

What did the reviewers find? Throat soreness and fever were reduced by antibiotics by about 50%, with the greatest difference seen at 3-4 days (which correlated to the time when symptoms of 50% of placebo patients had resolved). The overall number need to treat (NNT) to prevent one sore throat at day 3 was 5 (95% confidence interval [CI] 4.9-7.0); at 7 days it was 21 (95% CI 13.2-47.9). Additional subgroup analyses of symptom reduction found that antibiotics were more effective against symptoms at day 3, with a relative risk (RR) of 0.58 (95% CI 0.48-0.71) for GABHS-positive swabs vs. an RR of 0.78 (95% CI 0.63-0.97) if negative. At week 1, the RR with antibiotics was 0.29 (95% CI 0.12-0.70) vs. 0.73 with a control (95% CI 0.50-1.07). For suppurative complications, antibiotics reduced the incidence of acute otitis media (RR 0.30, 95% CI 0.15-0.58) with an NNT of 50, and of peritonsillar abscess (RR 0.15, 95% CI 0.05-0.47) with an NNT of 46.

A more recent national database study of more than 1 million sore throats found a much higher NNT of over 4,000.¹¹ For nonsuppurative complications, no conclusive evidence exists to support the belief that antibiotics protect against acute glomerulonephritis. Several studies found antibiotics reduced ARF by more than two-thirds (RR 0.22, 95% CI 0.02-2.08), with an NNT of 41.