Share this article on:

HIV incidence during a cluster-randomized trial of two strategies providing voluntary counselling and testing at the workplace, Zimbabwe

Corbett, Elizabeth La,b; Makamure, Beautyb; Cheung, Yin Buna; Dauya, Ethelb; Matambo, Ronnieb; Bandason, Tsitsib; Munyati, Shungu Sb,c; Mason, Peter Rb,d; Butterworth, Anthony Ea,b; Hayes, Richard Ja

doi: 10.1097/QAD.0b013e3280115402
Epidemiology and Social

Objective: To investigate HIV incidence during a trial of two voluntary counselling and testing (VCT) strategies. Counselling may promote beneficial behavioural change, although knowledge of negative status does not appear to contribute further benefit.

Design: The parent cluster-randomized trial demonstrated much greater uptake of VCT when counselling and rapid testing were available on-site (intensive VCT) than through pre-paid vouchers to an external provider (standard VCT). Anonymous HIV tests had been requested from all employees at enrolment and after 2 years intervention.

Methods: The study setting was 22 businesses in Harare, Zimbabwe. Participants were 3146 HIV-negative individuals remaining in employment at the end of intervention, of whom 2966 (94.3%) consented to repeat testing. VCT linked to basic HIV care was provided and the main outcome measures were HIV incidence under each study arm, as a retrospective secondary analysis.

Results: Mean VCT uptake in this cohort was 70.7 and 5.2%, respectively, in the intensive and standard arms. Crude HIV incidence was 1.21 per 100 person-years, with non-significantly higher rates in the intensive VCT arm [mean site incidence 1.37 and 0.95 per 100 person-years, respectively; adjusted rate ratio 1.49 (95% confidence interval 0.79–2.80).

Conclusions: Highly acceptable VCT did not reduce HIV incidence in this predominantly male cohort. HIV incidence was highest in the high uptake VCT arm, lending support to a US trial in which rapid testing appeared to have adverse behavioural consequences in some HIV-negative clients. Careful comparison of outcomes under different counselling and testing strategies is needed to maximize HIV prevention from global scale-up of VCT.

From the aDepartment of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK

bBiomedical Research and Training Institute, Harare

cNational Institute of Health Research, Harare

dDepartment of Medical and Laboratory Sciences, University of Zimbabwe, Harare, Zimbabwe.

Received 22 June, 2006

Revised 27 August, 2006

Accepted 27 September, 2006

Correspondence to Dr Liz Corbett, Biomedical Research and Training Institute, National Institute of Health Research, Josiah Tongogara Avenue, PO Box CY 1753 Causeway, Harare, Zimbabwe. E-mail:

© 2007 Lippincott Williams & Wilkins, Inc.