The adult prevalence of HIV in Zambia: Results from a population based mobile testing survey conducted in 2013-2014

Objective: To estimate the adult prevalence of HIV among the adult population in Zambia and determine whether demographic characteristics were associated with being HIV positive. Methods: A cross sectional population based survey to asses HIV status among participants aged 15years and above in a national tuberculosis prevalence survey. Counselling was offered to participants who tested for HIV. The prevalence was estimated using a logistic regression model. Univariate and multivariate associations of social demographic characteristics with HIV were determined. Results: Of the 46,099 individuals who were eligible to participate in the survey, 44,761 (97.1%) underwent pre-test counselling for HIV; out of which 30,605 (68.4%) consented to be tested and 30, 584 (99.9%) were tested. HIV prevalence was estimated to be 6.6% (95% CI 5.8-7.4); with females having a higher prevalence than males 7.7% (95% CI 6.8-8.7) versus 5.2% (95% CI 4.4-5.9). HIV prevalence was higher among urban (9.8%; 95% CI 8.8-10.7) than rural residents (5.0%; 95% CI 4.3-5.8). The risk of HIV was double among urban dwellers than among their rural counterparts. Being divorced or widowed was associated with a threefold higher risk of being HIV positive than being never married. The risk of being HIV positive was four times higher among those with tuberculosis than those without tuberculosis. Conclusions: HIV prevalence was lower than previously estimated in the country. The burden of HIV showed sociodemographic disparities signifying a need to target key populations or epidemic drivers. Mobile testing for HIV on a national scale in the context of TB prevalence surveys could be explored further in other settings.