Abstract
Single dose oral ciprofloxacin was given to all personnel in a naval training establishment as part of the management of an outbreak of meningococcal meningitis. Two thousand one hundred personnel received the drug and Neisseria meningitidis was eradicated from the pharynx of 97% of 570 who were swabbed two to four days later. In a cohort of 277 personnel who were followed for up to nine weeks, pharyngeal carriage was eliminated from 93% of 104 carriers. The overall prevalence of carriage fell from 19% to less than 1·5% as a result of the use of ciprofloxacin. Few side effects were encountered, compliance was good and meningococci resistant to the antibiotic were not found after therapy. A single oral dose of ciprofloxacin 500 mg eliminates pharyngeal carriage of N meningitidis effectively and has few adverse reactions.