Since health services normailly target a specific population, most decisions on needed interventions and achieved results are in some form based on data of the targeted population. Populations are not stable: people
are born, they die and migrate. If there are no reliable routine registration services in place as is the case in most less developed countries, it is not possible to have an up-to date picture of the targeted
population. That is, where demographic surveillance systems step in.
As with disease surveillance systems, there are numerous types of demographic surveillance systems. The most common form are governmental censi, which normally take place in intervalls of about ten years. Perhaps the
most popular example in history is the census of the Jews shortly before the birth of christ. These censi are static and do not allow tracking people over time.
Another approach is the longitudinal demographic surveillance system, which tracks people over time. In Nouna, Burkina Faso, I worked with my colleague Yazoumé Yé on the redesign of a database for a longitudinal demographic surveillance system, which we also linked to a GIS. It serves as the backbone for a number of a health related studies. A presentation on the DSS and how it could be linked to the national health reporting system is in the publications section of www.apuuli.de .