A transmission-virulence evolutionary trade-off explains attenuation of HIV-1 in Uganda

Journal article

Evolutionary theory hypothesizes that intermediate virulence maximizes pathogen fitness as a result of a trade-off between virulence and transmission, but empirical evidence remains scarce. We bridge this gap using data from a large and long-standing HIV-1 prospective cohort, in Uganda. We use an epidemiological-evolutionary model parameterised with this data to derive evolutionary predictions based on analysis and detailed individual-based simulations. We robustly predict stabilising selection towards a low level of virulence, and rapid attenuation of the virus. Accordingly, set-point viral load, the most common measure of virulence, has declined in the last 20 years. Our model also predicts that subtype A is slowly outcompeting subtype D, with both subtypes becoming less virulent, as observed in the data. Reduction of set-point viral loads should have resulted in a 20% reduction in incidence, and a three years extension of untreated asymptomatic infection, increasing opportunities for timely treatment of infected individuals.

Authors: Blanquart, F; Grabowski, M; Herbeck, J; Nalugoda, F; Serwadda, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: eLife Sciences Publications
• Journal: eLife
• Volume: 5
• Pages: e20492
• Publication date: 2016-11-01
• Acceptance date: 2016-11-04
• DOI: 10.7554/eLife.20492
• ISSN: 2050-084X