Epidemiology of invasive Haemophilus influenzae type b infections in Bedouins and Jews in southern Israel.

We report the epidemiology of invasive Haemophilus influenzae type b disease requiring hospital intervention in Southern Israel, an area that contains two ethnic populations, Bedouins and Jews. The study is based on 107 blood or cerebrospinal fluid culture-positive cases during the years 1984 to 1988. The annual incidence rate among children younger than 5 years of age was 51/100,000 (48/100,000 for Jews and 58/100,000 for Bedouins). Thirty-nine percent of patients had meningitis, 32% had pneumonia and 31% had otitis media. Epiglottitis was present in only one case (less than 1%). The median age was 8 months. Twenty-six percent of the cases were 6 months old or younger, 75% were 1 year old or younger and 87% were 18 months old or younger. Ninety-five percent of all meningitis cases occurred during the first 18 months of life. A projected number of 2938 hospitalization days and 9.8 deaths/year for a population in which 100,000 births occur yearly was calculated. The major impact of invasive H. influenzae type b infections and the very young age involved justify initiation of H. influenzae vaccine studies in our region.