Estimating the number of vertically HIV-infected children eligible for antiretroviral treatment in resource-limited settings

Abstract

With the gradual roll-out of antiretroviral therapy (ART) to delay progression of HIV disease in children in programmes across sub-Saharan Africa and resource-limited settings elsewhere, reliable information on the number of vertically infected children eligible for such treatment is urgently required. We present a model to estimate the number of vertically HIV-infected children by age who have progressed to moderate to severe disease (MSD) and as such are eligible for ART on the basis of clinical disease, allowing for: antenatal HIV prevalence, use of interventions to prevent mother-to-child transmission (PMTCT), infant feeding policies and availability of co-trimoxazole to prevent opportunistic infections that may hasten the onset of serious disease. The model assumptions were informed by published evidence and expert opinion; rates of progression to serious disease were inferred from mortality of infected and uninfected children of HIV-infected mothers; and mortality among children treated with ART was based on a study of treated children in Abidjan. To allow widespread use the model has been developed using the Excel spreadsheet software. With South Africa as a hypothetical example, published antenatal prevalence and demographic data, and assuming PMTCT coverage with single dose nevirapine of 11%, all exposed and infected children receive co-trimoxazole, and various infant feeding policy scenarios, estimated numbers of children eligible for ART are presented. This model is easy to implement and flexible and can be used in ART programmes at national and local level.