Hib Vaccine Has Cut H. influenzae Incidence Dramatically
Burden of disease is highest in youngest and oldest age groups
THURSDAY, Nov. 17 (HealthDay News) -- The introduction of the Haemophilus influenzae (H. influenzae) serotype b vaccine (Hib) has significantly reduced the incidence of invasive disease, according to a study published in the Dec. 15 issue of Clinical Infectious Diseases.
Jessica R. MacNeil, M.P.H., from the U.S. Centers for Disease Control and Prevention in Atlanta, and colleagues investigated trends in the incidence of H. influenzae since the introduction of Hib conjugate vaccine in the United States. Data were collected from 1989 to 2008 for invasive H. influenzae disease through Active Bacterial Core surveillance sites.
The investigators found that the estimated mean annual incidence of infection was 1.62 cases per 100,000 population, of which 15.3 percent were fatal cases. Adults aged 65 years or older had the highest incidence of infection. Among children aged younger than 5 years, those younger than 1 year had the largest burden of disease, with many cases occurring in pre-term or low-birth weight infants in the first month. American Indian and Alaska Native children had an estimated 10 percent of the total burden of disease in children aged younger than 5 years. A total of 7,559 cases of H. influenzae disease were reported from the Active Bacterial Core surveillance sites during 1989 to 2008, with small increases in the incidence of serotypes a, e, and f. The largest increase was seen in serotype f, mainly among adults aged 18 years or older.
"Since the introduction of Hib conjugate vaccine, the incidence of disease due to H. influenzae in the United States has decreased dramatically," the authors write.
One of the study authors disclosed financial relationships with pharmaceutical companies, including Sanofi-Pasteur, manufacturers of Hib vaccines.