The measurement of HIV-1 viral load in resource-limited settings: How and where?

There is an urgent need for low-cost, simple, and accurate human immunodeficiency virus type 1 (HIV-1) viral load monitoring technologies in resource-limited settings, particularly at the time of the scaling-up of first and second-line highly active antiretroviral therapies. This review describes the main characteristics and advantages/ disadvantages of three alternative HIV-1 viral load methods currently evaluated and used in developing countries, i.e., the Ultra p24 antigen assay, the ExaVir (R) Load reverse transcriptase activity test, and 'home-made' real-time PCR HIV-1 RNA techniques. This review discusses clinical results obtained with these three technologies in terms of correlation with commercial HIV-1 RNA assays, the impact of HIV-1 genetic diversity on quantification, as well as their usefulness for both the early diagnosis of pediatric HIV-1 infection and monitoring of highly active antiretroviral therapy efficiency. In addition, different strategies for HIV-1 viral load monitoring are discussed according to laboratory facilities in resource-constrained settings.