Rifampin for eradicating carriage of multiply resistant Haemophilus influenzae b.

We studied the efficacy of rifampin prophylaxis in reducing the prevalence of ampicillin- and chloramphenicol-resistant Haemophilus influenzae type b in four day care facilities after each center had individual cases of invasive infections (two meningitis, one pneumonia and one cellulitis) caused by multiply resistant organisms. Rifampin was given in a single daily dose of 20 mg/kg for 4 days. Cultures were taken pretreatment and 10 days after the last dose of rifampin. Included in the study were 174 children and 27 adults. We identified a total of 55 nasopharyngeal carriers; 45 received rifampin and 10 refused treatment. On the 10-day follow-up culture in the second sample, 95.5 and 20%, respectively, of treated and untreated children were no longer colonized with H. influenzae (P less than 0.001, Fisher's exact test). We conclude that rifampin can successfully reduce the prevalence of multiply resistant H. influenzae type b carriers attending day care centers.