The effect of a social network-based intervention on adherence to HIV preexposure prophylaxis and HIV viral suppression among Kenyan fishermen.

Objective: Social networks may play a vital role in shaping health behaviors, including engagement in HIV prevention and treatment. We evaluated the impact of an HIV status-neutral, social-network-based HIV self-testing and linkage intervention on preexposure prophylaxis (PrEP) adherence and HIV viral suppression among men working alongside Lake Victoria, Kenya.

Design: Cluster-randomized controlled trial.

Methods: After a census of fishermen, distinct social networks with highly socially connected men were identified, 'promoters' per network were recruited, and networks were randomized to study arms. Promoters distributed HIV self-tests kits to fishermen in their network and encouraged linkage and retention in prevention and care (intervention) or distributed vouchers redeemable for routine HIV testing (control). We report the tertiary outcomes of PrEP adherence, measured via a urine tenofovir assay among PrEP users and viral load among people with HIV (PWH). We conducted a logistic regression to evaluate the intervention's association with PrEP adherence and viral suppression.

Results: Of 733 baselined, 339 linked to clinics: 62 initiated PrEP, 25 were already on PrEP, and 166 were living with HIV. Urine tenofovir was detected among 12 of 70 participants who gave urine samples (13.6% control vs. 18.8% intervention), and 43 of 166 participants on antiretroviral therapy had detectable viral loads (40.2% control vs. 35.7% intervention). There were no significant differences by arm in urine tenofovir levels nor viral suppression.

Conclusion: A social network-based, status-neutral intervention that increased men's testing and linkage was not associated with PrEP adherence nor viral suppression. An adequately powered study is necessary to evaluate whether social-network-based interventions can improve these outcomes.