2021-01-312021-01-312014-06-051932-62031932-6203http://dx.doi.org/10.34944/dspace/528524901437 (pubmed)http://hdl.handle.net/20.500.12613/5303Objective: To reconstruct the local HIV-1 transmission network from 1996 to 2011 and use network data to evaluate and guide efforts to interrupt transmission. Design: HIV-1 pol sequence data were analyzed to infer the local transmission network. Methods: We analyzed HIV-1 pol sequence data to infer a partial local transmission network among 478 recently HIV-1 infected persons and 170 of their sexual and social contacts in San Diego, California. A transmission network score (TNS) was developed to estimate the risk of HIV transmission from a newly diagnosed individual to a new partner and target prevention interventions. Results: HIV-1 pol sequences from 339 individuals (52.3%) were highly similar to sequences from at least one other participant (i.e., clustered). A high TNS (top 25%) was significantly correlated with baseline risk behaviors (number of unique sexual partners and insertive unprotected anal intercourse (p = 0.014 and p = 0.0455, respectively) and predicted risk of transmission (p<0.0001). Retrospective analysis of antiretroviral therapy (ART) use, and simulations of ART targeted to individuals with the highest TNS, showed significantly reduced network level HIV transmission (p<0.05). Conclusions: Sequence data from an HIV-1 screening program focused on recently infected persons and their social and sexual contacts enabled the characterization of a highly connected transmission network. The network-based risk score (TNS) was highly correlated with transmission risk behaviors and outcomes, and can be used identify and target effective prevention interventions, like ART, to those at a greater risk for HIV-1 transmission.e98443-e98443enhttps://creativecommons.org/publicdomain/zero/1.0/AdultCaliforniaCluster AnalysisFemaleHIV InfectionsHIV-1HumansMaleMass ScreeningMiddle AgedPopulation SurveillanceSequence Analysis, DNASexual BehaviorSexual PartnersYoung Adultpol Gene Products, Human Immunodeficiency VirusArticle2021-01-31