Integration of a social network strategy into index testing to increase HIV case finding among Haitian migrants and their descendants in the Dominican Republic

IntroductionIncreasing effectiveness, efficiency, and reach of HIV case-finding strategies among priority populations is essential for epidemic control. Index testing is effective but presents potential risks, including stigma, violence, abandonment, and challenges such as fear of disclosure and reluctance to list contacts. We integrated the enhanced peer outreach approach (EPOA) social network strategy into index testing to increase case finding among Haitian migrants and individuals of Haitian descent in Dominican Republic. Methods The index-EPOA intervention implemented in two successive projects in the Dominican Republic offered index clients index-EPOA referral coupons to distribute to contacts. We analyzed retrospective client records from routine, aggregate program data. We compared overall case-finding rates pre-intervention (baseline October 2019-December 2020) and post-intervention (midline January 2021-March 2022; endline April 2022-June 2023), and case finding for index-EPOA versus standalone index. We calculated case-finding differences using the Student t-test. Results HS3/EHSEC tested 7,305 contacts of index clients, with 23% case finding. At baseline, 1,234 contacts were tested through standalone index, identifying 211 HIV-positive contacts with case finding at 17%. During the rollout of the intervention, the case-finding rate for standalone index testing remained similar to baseline (16%), while the rate for index-EPOA was 33%. Combined case finding for standalone index and index-EPOA increased to 22% at midline and 29% at endline, resulting in an overall case-finding rate of 25% during the intervention. The statistical analysis found overall case finding post-intervention (combined case-finding rate of 25% at midline + endline for standalone index and index-EPOA) significantly higher than at baseline (17% standalone index) (p < 0.001; 95% CI 8.5%-9.2%). Statistical significance of overall case-finding rates pre- and post-intervention was observed when disaggregated by sex: females 19% versus 26% (p < 0.001; 95% CI 7.2%-7.9) and males 15% versus 23% (p < 0.001; 95% CI 10.1%-10.9%). ConclusionsIntegrating the EPOA into index testing strengthened overall case finding for index testing among Haitian migrants and individuals of Haitian descent in the Dominican Republic, suggesting hybrid strategies can maximize program resources and impact.