Using geospatial mapping to design HIV elimination strategies for sub-Saharan Africa

Science Translational Medicine
29 March 2017 Vol 9, Issue 383
http://stm.sciencemag.org/

Research Articles
Using geospatial mapping to design HIV elimination strategies for sub-Saharan Africa
By Brian J. Coburn, Justin T. Okano, Sally Blower
Science Translational Medicine29 Mar 2017 Restricted Access
Mapping the geographic dispersion pattern of HIV-infected individuals in a sub-Saharan African country reveals the challenge to eliminating HIV.
Mapping a path to HIV elimination
About ~25 million individuals in sub-Saharan Africa are living with HIV. In new work, Coburn et al. design HIV elimination strategies for this region. The authors focused on Lesotho, where ~25% of the population is infected with HIV. They combined several large data sets and constructed a map that revealed the countrywide geographic dispersion pattern of HIV-infected individuals. They estimated that ~20% of the population lives in urban areas, and almost all rural communities have at least one HIV-infected individual. Their analyses showed that the spatial dispersion of Lesotho’s population hinders, and may even prevent, the elimination of HIV. This may hold true for other predominantly rural countries in sub-Saharan Africa.
Abstract
Treatment as prevention (TasP) has been proposed by the World Health Organization and the Joint United Nations Programme on HIV/AIDS (UNAIDS) as a global strategy for eliminating HIV. The rationale is that treating individuals reduces their infectivity. We present a geostatistical framework for designing TasP-based HIV elimination strategies in sub-Saharan Africa. We focused on Lesotho, where ~25% of the population is infected. We constructed a density of infection map by gridding high-resolution demographic data and spatially smoothing georeferenced HIV testing data. The map revealed the countrywide geographic dispersion pattern of HIV-infected individuals. We found that ~20% of the HIV-infected population lives in urban areas and that almost all rural communities have at least one HIV-infected individual. We used the map to design an optimal elimination strategy and identified which communities should use TasP. This strategy minimized the area that needed to be covered to find and treat HIV-infected individuals. We show that UNAIDS’s elimination strategy would not be feasible in Lesotho because it would require deploying treatment in areas where there are ~4 infected individuals/km2. Our results show that the spatial dispersion of Lesotho’s population hinders, and may even prevent, the elimination of HIV.