However, the risk of HIV infection may also depend on characteristics of sexual partnerships. Here we study how place-based selection of partners change transmission and the overall efficiency of PrEP. We used information about venues visited to meet casual sexual partners clubs, backrooms or saunas to define sexual networks.
In simulations, we found similar differences in HIV incidence when the choice of venues visited was not random. However, with the same amount of PrEP, the number of infections adverted could almost double depending on network structure and venues visited by PrEP users. This study shows that characteristics of the sexual network structure can strongly impact the effectiveness of PrEP interventions. These should be considered further to refine individual risk assessment and maximize the effect of individual-based prevention policies.
This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: For the simulation part of this work, all relevant data are within the paper and its Supporting Information files. Variable used to perform logistic regression and correlation analysis between venue visited are included in a Supporting Information files. Competing interests: The authors have declared that no competing interests exist. Differences in risk factors for HIV infection [ 2 ] contribute to the variability in the reported ranges [ 3 — 5 ].
In addition to differences in individual risk factors, the network of sexual contacts may change the probability of infection by HIV [ 9 , 10 ]. A better understanding of how sexual network structure changes HIV incidence is all the more required as new prevention approaches target all individuals whose personal characteristics put them at high risk. For example, in Western countries, the highly effective pre-exposure prophylaxis PrEP [ 11 — 13 ] is prescribed to MSM with a HIV-positive sexual partner or recent bacterial STI or a high number of sex partners or a history of inconsistent condom use or in commercial sex workers [ 14 , 15 ].
