Control of a school outbreak of serogroup B meningococcal disease by chemoprophylaxis with azithromycin and ciprofloxacin

OBJECTIVE: To assess the efficacy of azithromycin as a chemoprophylactic agent in meningococcal disease in pre-school aged children, and the safety of ciprofloxacin in children aged 6-16 years old. METHODS: After classic chemoprophylaxis with rifampicin failed to control a school outbreak of meningococcal disease in Cantabria (Spain), a second cycle of chemoprophylaxis was administered in the school. Azithromycin was administered in the nursery level (99 children, aged 3-5 years old) and ciprofloxacin was administered in the primary and secondary levels (795 children, aged 6-16 years old) and in the school's adult personnel (58 persons). The efficacy of chemoprophylaxis was studied through records of cases of meningococcal disease, the mandatory disease reporting system, and the school's absences. The safety of ciprofloxacin was studied using a questionnaire designed to determine the incidence of adverse osteoarticular effects, which was distributed to parents, school personnel and pediatricians within the school's area. RESULTS: The chemoprophylaxis administered controlled the outbreak. We collected 764 questionnaIres (response rate: 89.5 %). The incidence of arthralgia after ciprofloxacin was 0.9% in children and 3.3% in adults. All were mild and self-limiting without specific treatment, except in one patient (in the adult group) in whom arthralgia was present 1 month after prophylactic treatment. However, the arthralgia was so mild that the patient had not consulted her physician. Only three children had sought medical advice for arthralgia. Consequently, the incidence that would have been detected by the Spanish pharmacovigilance system would have been 0.4% in children and 0% in adults. CONCLUSIONS: Azithromycin was effective in controlling the outbreak in children aged between 3 and 5 years. Ciprofloxacin was safe and effective, with no serious or persistent osteoarticular effects in children. The incidence of arthralgia was lower in children than in adults.