Estimating the need of second-line antiretroviral therapy in adults in sub-Saharan Africa up to 2030: a mathematical model

, Abstract Background— The number of patients in need of second-line antiretroviral drugs is increasing in sub-Saharan Africa. We aimed to project the need of second-line antiretroviral therapy (ART) in adults in sub-Saharan Africa up to 2030. Methods— We developed a simulation model for HIV and applied it to each sub-Saharan African country. We fitted the number of adult patients on ART to observed estimates, and predicted first-and second-line needs between 2015 and 2030. We present results for sub-Saharan Africa, and 8 selected countries. We present 18 scenarios, combining the availability of viral load monitoring (VLm), speed of ART scale-up, and rates of retention and switching to second-line. HIV transmission was not considered. Findings— Depending on the scenario, 8·7–25·6 million people are expected to receive ART in 2020, of whom 0·5–3·0 million (2·9%–15·6%) will be receiving second-line ART. The percentage was highest (15·6%) in the scenario with perfect retention and immediate switching, no further scale-up, and universal routine VLm. In 2030, the range of patients on ART remained constant, but the number (proportion) of patients on second-line ART increased to 0·8–4·6 million (6·6%– 19·6%). The need of second-line ART was 2–3 times higher if routine VLm was implemented throughout the region, compared with a scenario of no further VLm scale-up. For each monitoring strategy the future proportion of patients on second-line ART differed only minimally between countries. Interpretation— The demand for second-line ART will increase substantially in the future as countries increase access to routine VLm. Funding— World Health Organization