Prevalence of and Factors Associated with the Use of HIV Serosorting and Other Biomedical Prevention Strategies Among Men Who Have Sex with Men in a US Nationwide Survey

Abstract

PrEP and treatment-as-prevention (TasP) are biomedical strategies to reduce HIV transmission. Some men who have sex with men (MSM) are combining biomedical strategies with HIV serosorting-termed "biomed matching" when both partners are either on PrEP or TasP, or "biomed sorting" when one partner is using PrEP and the other TasP. Nevertheless, there is limited data on the extent of biomed matching/sorting in large geographically diverse samples. In 2016-2017, 5021 MSM from across the US were surveyed about their HIV status and HIV viral load/PrEP use, as well as that of their recent casual male partners. For each participant, we calculated the proportion of his partners who were (1) HIV-positive and undetectable, (2) HIV-positive and detectable/unknown, (3) HIV unknown/undiscussed, (4) HIV-negative on PrEP, (5) HIV-negative, not on PrEP. In total, 66.6% (n = 3346) of participants were HIV-negative and not on PrEP, 11.9% (n = 599) on PrEP, 14.1% (n = 707) HIV-positive and undetectable, 1.1% (n = 55) HIV-positive and viral load detectable/unknown, and 6.2% (n = 313) HIV unsure/unknown. A participant's own HIV and PrEP status/was significantly associated with that of his partners (all p< 0.001), evincing evidence of both serosorting and biomed matching. Among men on PrEP and those who were HIV-undetectable, there was also some evidence to suggest these participants dually engaged in biomed matching as well as biomed sorting. We found evidence of biomed matching and sorting, which may compound its effectiveness for those using it (i.e., both partners bring biomedical protection). Unintended consequences of biomed matching/sorting include that men not using a biomedical strategy may be less likely to benefit from a partner's use of the strategy-potentially further driving disparities in HIV infections. Public health campaigns might be well served to highlight not only the benefits that biomedical HIV prevention strategies provide for their users (e.g., "being on PrEP protects me from getting HIV"), but also the benefits that a user brings to his partners (e.g., "my use of PrEP means my partners won't get HIV"), and the benefits of being with a partner who is using a biomedical strategy (e.g., "my partner's use of PrEP/TasP protects me from HIV").

Combination HIV Prevention Strategies Among Montreal Gay, Bisexual, and Other Men Who Have Sex with Men in the PrEP Era: A Latent Class Analysis

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Next-Wave HIV Pre-Exposure Prophylaxis Implementation for Gay and Bisexual Men

“…34,35 Other benefits of PrEP use have been documented from GBMSM on PrEP, including increasing feelings of intimacy with partners, improving one's sex life, and enhancing feelings of agency over sexual health. 33,34,36,37 Our own work (S.G.) indicates that PrEP use can have ancillary benefits of NEXT-WAVE PREP IMPLEMENTATION 255…”

Evidence of Nonrandom Mixing by Pre-exposure Prophylaxis Use Among Men Who Have Sex With Men Partnerships in Melbourne, 2016 to 2018

“… 2 – 5 We found that among MSM enrolled in a cross-sectional survey in Montreal, Canada, those on PrEP reported a higher proportion of partners on PrEP among their HIV-negative partners than would be expected by chance alone (50.6% vs. 28.5%)—a pattern we referred to as “PrEP-matching.” 2 Similarly, using data from a nationwide survey of MSM in the United States, Grov et al found that MSM who used PrEP reported a larger proportion of partners on PrEP among their casual male partners, compared with HIV-negative MSM who did not use PrEP (41% vs. 22%)—a pattern referred to as a form of “biomed-matching” by the authors. 3 The term “biomed-matching” was originally introduced by Newcomb et al 4 to describe an emerging risk reduction strategy used by MSM in the era of biomedical HIV prevention, wherein both individuals in the partnership use PrEP or have undetectable viral load to engage in condomless sex. Indeed, Prescott et al, 5 found that among a sample of MSM who use alcohol in San Francisco, United States, approximately half of the sexual partnerships among MSM using PrEP were concordant in their use of biomedical prevention, and their concordant use of PrEP was associated with greater engagement in condomless anal sex.…”