THE RATIONALE FOR POPULATION-BASED SURVEILLANCE FOR HAEMOPHILUS-INFLUENZAE TYPE-B MENINGITIS

Although Haemophilus influenzae type b (Hib) conjugate vaccines have b een spectacularly successful, nearly eradicating Hib disease in countr ies where used routinely, they are relatively expensive. In many count ries the incidence of Haemophilus influenzae type b (Hib) disease is u ncertain, and it is unclear whether the local burden of Hib disease wa rrants the costs of adding Hib vaccine to the routine immunization pro gram. Population-based surveillance to assess the local burden of Hib disease can help decision makers with this process. Although pneumonia is more common than meningitis, surveillance for Hib meningitis and i nvasive disease is likely to be more feasible and efficient than surve illance for Hib pneumonia. Standardization of laboratory methods for t he isolation and identification of H. influenzae from CSF specimens is essential to successful surveillance. Should a country decide to intr oduce Hib conjugate vaccine as a routine immunization, population-base d surveillance data collected before and after the introduction of vac cine can be used to monitor its impact. Finally population-based surve illance for bacterial meningitis also can provide information on the i ncidence of pneumococcal and meningococcal infections and on serogroup or serotype distributions that will be important when evaluating the new vaccines for those pathogens that are being developed.