Bacteremia due to Haemophilus infections: a retrospective study with emphasis on the elderly

We performed a retrospective study of all patients in a large health maintenance organization in Southern California who were identified as having positive blood cultures for Haemophilus organisms during a 20-month period (September 1990 to May 1992) to assess the incidence, presentation, and predisposing conditions of bacteremia due to these organisms and to examine some of the features of these infections in the elderly. Thirty-eight patients with bacteremia due to haemophilus infections were identified. Ten (26.3%) patients were 65 years of age or older. The incidence of bacteremic haemophilus infections in the elderly group was estimated at 2.7 per 100,000 individuals per year, which was almost three times greater than that for the younger age groups studied. When analyzed statistically, the presenting feature of the infection did not differ among age groups. Six patients died, four of whom were elderly. All six deaths were due to nontypable Haemophilus influenzae strains. Cancer was the only chronic underlying condition frequently found among the elderly patients. Three of 10 elderly patients lived in nursing homes; all three were infected with nontypable H. influenzae strains, and all three died.