Benefit of viral load testing for confirmation of immunological failure in HIV patients treated in rural Malawi

Abstract

Objective Viral load testing is used in the HIV programme of Chiradzulu, Malawi, to confirm the diagnosis of immunological failure to prevent unnecessary switching to second-line therapy. Our objective was to quantify the benefit of this strategy for management of treatment failure in a large decentralized HIV programme in Africa. Methods Retrospective analysis of monitoring data from adults treated with first-line antiretroviral regimens for >1year and meeting the WHO immunological failure criteria in an HIV programme in rural Malawi. The positive predictive value of using immunological failure criteria to diagnose virological failure (viral load >5000copies/ml) was estimated. Results Of the 227 patients with immunological failure (185 confirmed with a repeat CD4 measurement), 155 (68.2%) had confirmatory viral load testing. Forty-four (28.4%) had viral load >5000copies/ml and 57 (36.8%) >1000copies/ml. Positive predictive value was 28.4% (95% CI 21.4-36.2%). Repeat CD4 count testing showed that 41% of patients initially diagnosed with immunological failure did no longer meet failure criteria. Conclusions Our results support the need for confirming all cases of immunological failure with viral load testing before switching to second-line ART to optimize the use of resources in developing countries. © 2011 Blackwell Publishing Ltd.