Comparative efficacy of ceftriaxone and rifampicin in eradicating pharyngeal carriage of group A Neisseria meningitidis.

During an outbreak of meningococcal meningitis in Saudi Arabia, oral rifampicin (four doses in two days) was compared with a single intramuscular dose of ceftriaxone for prophylaxis in family contacts of patients with meningococcal disease. Pharyngeal samples were taken for culture before and 1 and 2 weeks after administration. Both follow-up cultures indicated that ceftriaxone was significantly more effective. At 1 week the eradication rates for ceftriaxone and rifampicin were 97% and 75%; at 2 weeks they were 97% and 81%, respectively. No serious side-effects were associated with either agent. Ceftriaxone may provide an effective alternative to rifampicin for prophylaxis in meningococcal contacts.