Rifampin-resistant meningococcal disease.

Rifampin-resistant meningococcal disease occurred in a child who had completed rifampin chemoprophylaxis for exposure to a sibling with meningococcemia. Susceptibility testing of 331 case isolates found only 1 other case of rifampin-resistant disease in Minnesota, USA, during 11 years of statewide surveillance. Point mutations in the RNA polymerase Beta subunit (rpoB) gene were found in isolates from each rifampin-resistant case-patient.