Scaling up HIV voluntary counseling and testing in Africa: what can evaluation studies tell us about potential prevention impacts?

Although there is a widespread belief that scaling up HIV voluntary counseling and testing (VCT) programs in Africa will have large prevention benefits through reductions in risk behaviors, these claims are difficult to establish from existing evaluations of VCT. Considerations from behavioral models and the available data suggest that as VCT coverage expands, marginal program effects are likely to decline owing to changes in the degree of client selectivity, and that potential uptake among those at highest risk is uncertain. The article also assesses two other common perceptions about VCT in Africa: that a policy of promoting couples-oriented VCT would be more successful than one emphasizing individual testing and that VCT demand and prevention impacts will be enhanced where scaling up is accompanied by the provision of antiretroviral drugs.