HAEMOPHILUS-INFLUENZAE MENINGITIS IN ADULTS

Haemophilus influenzae meningitis is rare in adults. We reviewed the m icrobiological records of cerebrospinal fluid (CSF) and blood cultures and file medical records of patients with bacterial meningitis admitt ed to Chang Gung Memorial Hospital from January 1978 to May 1996. Haem ophilus influenzae meningitis was found in six adult patients, account ing for 1.8% of 326 bacteriologically proven adult cases of meningitis diagnosed between January 1984 and May 1996. Predisposing conditions included head trauma and/or neuro-surgical procedure in four patients and an extracranial extension of a pituitary adenoma in a diabetic pat ient. None of them had altered consciousness on the day of treatment. A CSF cell count less than 500 X 10(6) leukocytes/liter was noted in t hree patients. Antibiotic therapy was successful in all patients. Thus , predisposing conditions, particularly head trauma and/or neurosurgic al procedure, are commonly present in adult:patients with H. influenza e meningitis. Patients with the infection may have a low cellular coun t in the CSF that may be readily misinterpreted as meningitis caused b y other pathogens. (C) 1998 Elsevier Science Inc.