Epidemiology of Haemophilus influenzae Type b Infections

Abstract

In summary, H influenzae type b is recognized as the most common cause of bacterial meningitis in the United States. Documentation of the frequency of other associated invasive infections has increased the importance of prevention of infection with this organism. Although all children younger than the age of 5 years are at greatest risk of invasive disease due to this pathogen, the peak occurrence of illness in those infants younger than 1 year of age means that a preventive measure must be effective in children younger than the age of 6 months. There would appear to be increased risk for some specific populations such as native Alaskans, American Indians, blacks, and Hispanics, but environmental and socioeconomic variables may be responsible for this increased risk. Attendance at a day-care center or nursery, the presence of a school-age sibling, and crowding in the home may be factors contributing to primary invasive disease. An ideal immunogen would be administered to children within the framework of other routinely administered childhood immunizations as early as 6 weeks to 2 months of age. As it is not possible to predict accurately which individual children are at risk, it is important to work toward effective universal immunization of all young infants.