Social networks and tie strength predict outcomes of HIV+ youth in search trial

Background: HIV+ youth in sub-Saharan Africa are at high risk of virologic failure on ART; peer support within their social networks may improve clinical outcomes. We used comprehensive social network and HIV testing data from the SEARCH test-and-treat trial (NCT01864603) to evaluate whether HIV+ youth with HIV+ social network contacts at baseline were more likely than those without this support to engage in care and virally suppress. Methods: Adult (≥ 15 years) residents enumerated during a census in 32 communities in rural Kenya and Uganda named social contacts in five domains: health, money, emotional support, food, and free time. Named contacts were matched to enumerated residents to build social networks among 150,395 adult residents; 90% were tested for HIV. Among youth (15-24 years) who were ART-naive at baseline (2013-2014), we evaluated whether having ≥1 baseline network contact who was i) HIV+, or ii) HIV+ and virally suppressed (HIV RNA <400 copies/ml) predicted ART initiation and viral suppression 3 years later, and whether the association was greater for strong ties (network contacts named in >1 domain). We used logistic regression with robust standard errors to adjust for sex, study arm, new diagnosis, and region. Results: Among 1,120 HIV+ youth who were ART-naive at baseline, 857 remained alive and resident in the community after 3 years of follow-up. At 3 years, 68% (579/857) had engaged in ART care and among 521 with viral loads, 400 (77%) were virally suppressed. Youth named an average of 2.7 contacts (SD 3.1); 275 (32%) named ≥1 HIV+ contact and 81 (9%) had ≥1 virally suppressed contact. 340 (42%) named ≥1 strong tie; 117 (15%) had HIV+ strong ties and 31 (4%) had virally suppressed strong ties. Youth with ≥1 HIV+ baseline contact were more likely to initiate ART (aOR 1.76; 1.26-2.46) and youth with ≥1 virally suppressed baseline contact were more likely to be suppressed themselves 3 years later (aOR 1.80; 1.11-2.89). The magnitude of these associations was (nonsignificantly) greater if ties were strong: ≥1 HIV+ strong tie was associated with ART initiation (aOR 2.07; 1.27-3.37) and ≥1 virally suppressed strong ties was associated with viral suppression (aOR 2.53; 1.18-5.42). Conclusion: HIV+ peers, particularly those with viral suppression, in the local social networks of ART-naive HIV+ youth in rural East Africa may support engagement in care and viral suppression. Interventions that increase social connections to HIV-infected youth in HIV-care may improve clinical outcomes.