[Bronchopneumonia caused by Neisseria meningitidis--probable transmission by a family member who had been in Hong Kong].

A 22-year-old man came to our hospital complaining of bloody sputum. No abnormalities were seen on a chest X-ray film, but computed tomography of the chest showed infiltrates in the middle and lower lung fields. Neisseria meningitidis was isolated from cultured samples of naso pharyngeal secretions, from sputum, and from a sample obtained during bronchoscopy; bacterial bronchopneumonia was diagnosed. Family members were studied for meningococcal infection, and the bacterium was cultured from a nasopharyngeal smear from the patient's mother. The mother was asymptomatic. Both bacteria belonged to Group B serum group and their drug sensitivities were equal. The patient's family had been in Hong Kong, where this bacterium is endemic, for two years. They then returned to Japan and started to live together with the patient nine months before the onset of symptoms. The mother may have become infected in Hong Kong and may have passed the bacterium to her son after her return. Oral ampicillin was effective in both mother and son. Investigation of the patient's family was necessary to establish the probable route of infection and to decide on the treatment.