Oral erythromycin prophylaxis against streptococcus pyogenes infection in penicillin-allergic military recruits: A randomized clinical trial

Historically, military recruits have required benzathine penicillin G to prevent epidemics of Streptococcus pyogenes. In this randomized clinical trial, low-dose oral erythromycin was evaluated as an alternative for prophylaxis against group A β-hemolytic streptococci in penicillin-allergic recruits. US Marine Corps recruits (186) reporting penicillin allergy were randomly given either oral erythromycin (250 mg twice a day) or a vitamin (one tablet daily) for 60 days. Evidence of infection was defined as a two-dilution rise in anti-streptolysin O titer. The erythromycin group had a significantly lower risk of S. pyogenes infection than did the vitamin group (relative risk 0.44; 95% confidence interval, 0.22-0.89). There was no significant difference among the treatment groups in isolation of group A β-hemolytic streptococci from throat cultures. Low- dose oral erythromycin appears as effective as benzanthine penicillin G in preventing S. pyogenes infection.