Epidemiological analysis of the quality of HIV sero-surveillance in the world: how well do we track the epidemic?

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Objective: The objective of this paper was to analyse the quality of HIV/AIDS, sentinel surveillance systems in countries and the resulting quality of the data used to make estimates of HIV/AIDS prevalence and mortality. Methods: Available data on sero-surveillance of HIV/AlDS in countries were compiled in the process of making the end of 1999 estimates of HIV/AIDS. These data came primarily from the HlV/AIDS Surveillance Database developed by the United States Census Bureau, from a database maintained by the European Centre for the Epidemiological Monitoring of AIDS and all country reports on sentinel surveillance that had been provided to World Health Organization or UNAIDS. Procedures were developed to score quality of surveillance systems based on four dimensions of quality: timeliness and frequency; appropriateness of groups; consistency of sites over time; and coverage provided by the system. In total, the surveillance systems from 167 countries were analysed. Results: Forty-seven of the 167 countries whose surveillance systems were rated were judged to have fully implemented sentinel surveillance systems; 51 were judged to have systems that had some or most aspects of a good HIV surveillance system in place and 69 were rated as having poorly functioning or non-existent surveillance systems. Conclusion: This analysis suggets that the quality of HIV surveillance varies considerably. The majority of countries most affected by HIV/AIDS have systems that are providing sufficient sero-prevalence data for tracking the epidemic and making reasonable estimates of HIV prevalence. However, many countries have poor systems and strengthening these is an urgent priority. (Editor' s abstract)