A two-year prospective, nationwide study to determine the epidemiology and impact of invasive childhood Haemophilus influenzae type b infection in Israel. The Israeli Pediatric Bacteremia and Meningitis Group.

Accurate data on invasive Haemophilus influenzae type b (Hib) disease from countries other than the United States and western Europe are limited, and none are available from the Middle East. We report the results of a nationwide prospective epidemiological study in Israel whose purpose was to provide a background for decisions regarding the need for Hib conjugate vaccinations. During the 2 study years, 344 patients less than 13 years of age with a positive blood or CSF culture for Hib were seen in 25 medical centers in which pediatric patients were hospitalized. The overall incidence of Hib disease was 34 per 100,000 persons less than 5 years old, an incidence in the range of those reported for western Europe. Twenty-two percent of patients were less than or equal to 6 months old, 69% were less than or equal to 12 months, 87% were less than or equal to 18 months, and 93% were less than or equal to 24 months. Thus, our findings represent a unique epidemiological pattern: the age distribution of our patients resembles that of immunologically compromised populations or of persons living in less-industrialized areas, but the incidence of disease is similar to that found in western Europe. In view of these data, the Israeli Ministry of Health decided to license conjugate vaccines for immunization of infants beginning at 2 months of age.