Demographic surveillance sites and emerging challenges in international health

At present, the long-term social, economic, and demographic impact of major diseases in developing countries can only be estimated using models since there are no empirical data on age and cause-specific morbidity and mortality. Reliable estimates require the input of accurate data into the models, from as many geographical zones as possible. With the collapse of vital registration systems and the rudimentary state of health information systems in most of the developing world, estimated projections are sometimes based on educated guesses and intuition rather than fact. (1) The investment needed to improve health information in these countries is unlikely to be made in the near future. Strong national health research systems are needed to improve health. For developing countries to indigenize health research systems, it is essential to build capacity. (2,3) A local cadre of research scientists is urgently needed, particularly in epidemiology, statistics, immunology, and the clinical sciences. Global disease control initiatives exist in countries where there are fewer than four epidemiologists and only one statistician. Training abroad has been an invaluable stopgap measure, but demand has consistently outstripped supply. The question remains: where is the next generation of research scientists in the developing world going to be trained? One approach could be to strengthen sites that maintain Demographic Surveillance Systems (DSS). Demographic surveillance is the process of defining risk and corresponding dynamics in rates of birth, deaths, and migration in a population over time. Surveillance systems are often set up around specific intervention studies and later convert into standing DSS sites that can form a platform for further studies. There are over 30 DSS sites in Africa, Asia, and the Americas. At most sites, core demographic data are supplemented with social and economic correlates of population and health dynamics. (4) DSS sites have provided platforms for research on pneumococcal vaccines in Basse (Gambia), maternal mortality in Matlab (Bangladesh), non-communicable disease in Filabavi (Viet Nam), and HIV/STIs (sexually transmitted infections) in Rakai (Uganda), insecticide-treated nets in Navrongo, Farafeni (Gambia), Ifakara (United Republic of Tanzania), Kisimu (Kenya), and Oubritenga (Burkina Faso). DSS sites attract professionals from diverse backgrounds. Highly-qualified demographers, epidemiologists, sociologists, clinicians, and economists enable a continuum of research and a multifaceted examination of health problems and provide an ideal environment for training of research professionals. DSS sites in the Gambia, Navrongo in Ghana, Filabavi in Viet Nam, and Agincourt in South Africa, among others, serve as field sites for graduate students of international health. DSS sites have come together under the banner of the INDEPTH Network, run by the developing countries with advice and financial input from developed countries. …