BACKGROUND: The Transmission Reduction Interventions Project (TRIP) is network-based intervention that aims at decreasing HIV-1 spread. We herein explore associations between transmission links as estimated by phylogenetic analyses, and social network-based ties among persons who inject drugs (PWID) recruited in TRIP.
METHODS: Phylogenetic trees were inferred from HIV-1 sequences of TRIP participants. Highly supported phylogenetic clusters (transmission clusters) were those fulfilling three different phylogenetic confidence criteria. Social network-based ties (injecting or sexual partners, same venue engagement) were determined based on personal interviews, recruitment links and field observation.
RESULTS: TRIP recruited 356 individuals (90.2% PWID) including HIV negative controls; recently HIV-infected seeds; long-term HIV-infected seeds; and their social network members. Of the 150 HIV(+), 118 (78.7%) were phylogenetically analyzed. Phylogenetic analyses suggested the existence of 13 transmission clusters with 32 sequences. Seven of these clusters included 14 individuals (14/32, 43.8%) who also had social ties with at least one member of their cluster. This proportion was significantly higher than what was expected by chance.
CONCLUSIONS: Molecular methods can identify HIV-infected people socially-linked with another person in about half of the phylogenetic clusters. This could help public health efforts to locate individuals in networks with high transmission rates.
Molecular analysis of HIV-1 infected individuals in a network-based intervention (TRIP): Phylogenetics identify HIV-1 infected individuals with social links
Journal of Infectious Diseases, 218 (5), 707-715. doi: 10.1093/infdis/jiy239. PMCID: PMC6057507.