Production of Haemophilus influenzae b meningitis in infant rats by intraperitoneal inoculation

Sprague-Dawley rats have a marked age-related susceptibility to Haemophilus influenzae type b that does not correlate with serum bactericidal activity. Eighty percent of 5-day-old animals that survive to 48 h after an intraperitoneal inoculation of a mean lethal dose of bacteria have histologically documented meningitis. Animals surviving the inoculations as infants manifest cerebral dysfunction as adults. This model should facilitate experimental study of bacterial meningitis.