The context of HIV/AIDS surveillance.

HIV surveillance and diagnostic testing for HIV infection share elements in common, yet differ notably in context. Clinical testing provides vital information for individual medical and behavioral decisions, whereas surveillance, which focuses on populations, provides information to develop policy, direct resources, and plan services. HIV/AIDS surveillance has evolved over the course of the epidemic, reflecting changes in scientific knowledge, populations affected, and information needs. Likewise, the benefits of early diagnosis of HIV have become increasingly apparent with advances in HIV treatment. This article examines the changing context of HIV/AIDS surveillance and discusses the potential impact of HIV surveillance practices and policies on HIV testing behaviors. Special emphasis is placed on the importance of protecting the confidentiality of HIV/AIDS surveillance data and on the role of health department in monitoring the impact of surveillance policies on test-seeking patterns and behaviors.