The need for second-line antiretroviral therapy in adults in sub-Saharan Africa up to 2030: a mathematical modelling study

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 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 used the WHO country intelligence database to estimate the number of adult patients receiving antiretroviral therapy from 2005 to 2014. We fitted the number of adult patients receiving antiretroviral therapy to observed estimates, and predicted first-line and second-line needs between 2015 and 2030. We present results for sub-Saharan Africa, and eight selected countries. We present 18 scenarios, combining the availability of viral load monitoring, speed of antiretroviral scale-up, and rates of retention and switching to second-line. HIV transmission was not included.

Findings: Depending on the scenario, 8·7-25·6 million people are expected to receive antiretroviral therapy in 2020, of whom 0·5-3·0 million will be receiving second-line antiretroviral therapy. The proportion of patients on treatment receiving second-line therapy was highest (15·6%) in the scenario with perfect retention and immediate switching, no further scale-up, and universal routine viral load monitoring. In 2030, the estimated range of patients receiving antiretroviral therapy will remain constant, but the number of patients receiving second-line antiretroviral therapy will increase to 0·8-4·6 million (6·6-19·6%). The need for second-line antiretroviral therapy was two to three times higher if routine viral load monitoring was implemented throughout the region, compared with a scenario of no further viral load monitoring scale-up. For each monitoring strategy, the future proportion of patients receiving second-line antiretroviral therapy differed only minimally between countries.

Interpretation: Donors and countries in sub-Saharan Africa should prepare for a substantial increase in the need for second-line drugs during the next few years as access to viral load monitoring improves. An urgent need exists to decrease the costs of second-line drugs.

Funding: World Health Organization, Swiss National Science Foundation, National Institutes of Health.

Figure 1

Projected number of patients on first- and second-line ART in sub-Saharan Africa 2003–2030 with perfect retention and switching, rapid ART scale-up and universal routine viral load monitoring (panel A), and with realistic retention and switching, stable ART scale-up and routine viral load monitoring in either all countries except those that do not recommend it (panel B), or only in the countries that already implement it (panel C). The blue area shows patients on first-line ART and the red area patients on second-line ART; past estimates (before 2015) are shown in light blue/pink respectively. The black vertical line shows year 2020.