introduction of vaccines for haemophilus influenzae type b disease: Implications of Population-Based Surveillance in asia

Kilgore PE, International Vaccine Institute, Seoul, Korea.

For public health policy-makers in Asia, the introduction of new vaccines for the control of infant and childhood diseases will become more challenging as new vaccines are developed and become available. As a result, the use of disease burden information will become an increasingly important as tool to assist in making difficult policy choices. Since September 1999, three surveillance field sites have been established in Asia to measure the incidence of invasive bacterial meningitis over a 24-month period. Patients evaluated in these systems receive standardized clinical and microbiologic evaluations to determine the presence of invasive bacterial meningitis and other invasive bacterial diseases. At the conclusion of a 2-year surveillance period in Korea and in Vietnam, the ongoing surveillance studies of invasive bacterial diseases will provide critical data on disease burden. The field site in Chonbuk Province, Korea will complete a 24-month period of meningitis surveillance activities in December 2001. The field site in Hanoi, Vietnam will complete meningitis surveillance in February 2002. Important outcomes to consider in future decisions regarding Haemophilus influenzae type b (Hib) vaccine introduction will be hospitalizations, deaths and disability following acute episodes of Hib meningitis as well as other invasive disease manifestations such as pneumonia, septicemia and epiglottitis. In addition, preliminary results in some cases suggest that antibiotic resistance also plays a role in prolonging resolution of the acute meningitis episodes when patients are treated in-hospital with routine 1^st and 2^nd line antibiotic regimens. With the use of detailed surveillance data that provides information on disease outcomes that are preventable with immunization, we will construct country-specific decision-analytic models to estimate the economic implications of Hib immunization in Korea and Vietnam. Preliminary data collected to date in each field site enable us now to formulate rationale plans for surveillance data analysis, economic analysis and data dissemination to public health policy-makers.