National HIV prevalence surveillance among TB patients through periodic surveys: experience in Cambodia.

SETTING: The National Tuberculosis Programme (NTP) in Cambodia, one of the countries most affected by tuberculosis (TB) and human immunodeficiency virus (HIV) infection in Asia.

OBJECTIVE: To conduct national HIV prevalence surveillance among TB patients, to estimate HIV prevalence among TB patients and to determine the potential of the NTP as a source for antiretroviral treatment (ART) scale-up.

DESIGN: Anonymous unlinked cross-sectional seroprevalence surveys including all TB patients registered by the NTP in January 2003 and January 2005.

RESULTS: HIV prevalence among all TB patients fell from 11.8% in 2003 to 9.9% in 2005 (P < 0.05). In 2003 and 2005, respectively 265 and 261 TB patients were identified as HIV-positive in a given month. Among new smear-positive pulmonary TB patients, the prevalence dropped from 8.2% to 5.2% (P < 0.01).

CONCLUSION: The two periodic surveys demonstrated a high prevalence of HIV among TB patients in Cambodia. However, the declining incidence of HIV from the late 1990s might now be reflected in the HIV prevalence among new smear-positive TB patients. The NTP is a potential source of ART if HIV counselling and testing are made more widely available to TB patients.