Haemophilus influenzae meningitis in adults.

Haemophilus influenzae meningitis though common in childhood is rarely seen in the adult. During the past four years eight cases of H. influenzae meningitis have been seen in St. Thomas's Hospital and four of these were in patients over 20 years old. There was a possible predisposing condition in two patients. In each case there was difficulty in identification of the organism in the Gram-stained film of the cerebrospinal fluid deposit.