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 >1 year 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 >5000 copies/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 >5000 copies/ml and 57 (36.8%) >1000 copies/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.