Should you treat carriers of pharyngeal group A strep?
No clear consensus on prophylaxis
In 1995, the Centers for Disease Control and Prevention convened a consensus group to address the issue of prophylaxis for people exposed to GAS-positive carriers, but the consensus group failed to reach a definitive conclusion.4
Clindamycin works; penicillin + rifampin is also effective
Most RCTs investigating effective antibiotic treatment of GAS target cases of acute pharyngitis. A wide variety of antibiotics have been studied, including cefadroxil, amoxicillin, amoxicillin/clavulanate, cefuroxime, azithromycin, cefprozil, and cephalexin. We evaluated 41 of 43 studies of treatment of acute GAS. Only 2 RCTs specifically address effective antibiotic regimens for treating GAS carriers.
The most recent study demonstrated a significantly greater eradication rate with oral clindamycin than penicillin plus rifampin (P<.025).5 Compared with penicillin plus rifampin after 3 weeks of therapy, the number needed to treat (NNT) for clindamycin was 4.5
An older study found intramuscular penicillin plus 4 days of oral rifampin superior to intramuscular penicillin alone (P<.005) or no treatment at all (P<.0005) for eradicating GAS in carriers.1 Compared with placebo after 3 weeks of therapy, the NNT for penicillin plus rifampin was 2.1
The IDSA recommends a 10-day course of amoxicillin/clavulanate as an alternative treatment option.2
Recommendations
The 2006 Red Book: Report of the Committee on Infectious Diseases notes 6 possible indications for treating GAS carriers; they’re nearly identical to circumstances 2 through 7 in the evidence-based answer.6 The Red Book also acknowledges several treatment options, including clindamycin, amoxicillin, azithromycin, and penicillin plus rifampin. A 10-day course of oral clindamycin, however, is the therapy of choice.6
