Zambia has used the antenatal care (ANC) sentinel surveillance data as a principal means of monitoring the spread of HIV for almost a decade (Fylkesnes et al., 1998). The ANC sentinel surveillance system includes both urban and rural sites with at least two sites in each of the country’s nine provinces. Over time, there has grown a need to expand the tools for monitoring HIV trends in the general population with population-based surveys. UNAIDS recommends carrying out population-based surveys in catchment areas of ANC sentinel surveillance sites to calibrate the results of routine surveillance systems (UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance, 2000). A number of population-based surveys have been carried out in specific catchment areas of the ANC sentinel surveillance system in Zambia to calibrate the results of the ANC system to the general population and to monitor HIV trends in the general population. (For a comparison of ANC surveillance estimates and the ZDHS rates, see Section 14.4.) However, the 2001-2002 ZDHS is the first nationally-representative population-based survey to estimate the prevalence of HIV in Zambia. In addition to HIV testing, syphilis was included from among other sexually transmitted infections (STIs) because it is an important bio-marker of the prevalence of STIs which are a major risk factor in the heterosexual transmission of HIV in the Zambian population