Outbreak of meningococcal disease in a family.

An outbreak of three cases of meningococcal disease occurring in a family of 14 is presented. Three of the children, between the ages of 10 months to 10 years, were hospitalized. Two of them showed positive signs of meningitis, and one had evidence of bacteremia. Neisseria meningitidis was isolated from a blood sample of one patient and a CSF sample of another. The organism was also recovered from the nasopharyngeal secretion of four other adult members of the family. All three hospitalized children were treated with parenteral penicillin and responded well to therapy. The rest of the family was treated with oral rifampin, and subsequent cultures of the nasopharynx were negative.