Near full-length genomic sequencing and molecular analysis of HIV-infected individuals in a network-based intervention (TRIP) in Athens, Greece: Evidence that transmissions occur more frequently from those with high HIV-RNA.

Background: TRIP (Transmission Reduction Intervention Project) was a network-based, contact tracing approach to locate and link to care, mostly people who inject drugs (PWID) with recent HIV infection. Objective: We investigated whether sequences from HIV-infected participants with high viral load cluster together more frequently than what is expected by chance. Methods: Paired end reads were generated for 104 samples using Illumina MiSeq next-generation sequencing. Results: 63 sequences belonged to previously identified local transmission networks of PWID (LINs) of an HIV outbreak in Athens, Greece. For two I IIV-RNA cut-offs (10(5) and 10(6) IU/mL), HIV transmissions were more likely between PWID with similar levels of HIV-RNA (p<0.001). 10 of the 14 sequences (71.4%) from PWID with HIV-RNA >10(6) IU/mL were clustered in 5 pairs. For 4 of these clusters (80%), there was in each one of them at least one sequence from a recently HIV-infected PWID. Conclusion: We showed that transmissions are more likely among PWID with high viremia.