796. HIV transmission clusters among people who inject drugs in North Carolina, 2010 to 2021

Abstract Background The marked increase in injecting drug use (IDU) in the past decade presents concern for increased HIV transmission among people who inject drugs (PWID) and explosive outbreaks. Among statewide HIV molecular surveillance, we assessed demographic, clinical, and reported behavioral risk factors associated with HIV clusters involving PWID in North Carolina (NC). Methods Persons ≥ 13 years old with HIV-infection residing in NC with ≥ 1 partial pol sequence collected between April 2010 and December 2021 were included in the study. We used an automated cluster analysis pipeline to detect genetic clusters (nextHIV2), defined as ≥ 2 sequences with a pairwise genetic distance < 1.5%. Logistic regression was used to estimate the risk and adjusted odds ratios of the relationship between the demographic factors that were likely associated with HIV clustering. Graphics were generated using the R packages ggplot2 and igraph. Results Among 19,641 persons with a sequence, 1,611 were PWID. Of these, 347 (21.5%) PWID were members of 248 clusters involving a total of 2,083 persons (size ranged 2–104). Sixty-four clusters (25%) had ≥2 PWID, whereas 2 (1%) included at least 5 PWID. The most commonly injected drug among cluster members was methamphetamine (19%). Overall, in a univariate analysis, younger age, dual risks of male-to-male sex and IDU, having sex under the influence of drugs, recent IDU (past 12 months), acute HIV infection, higher viral loads and higher CD4 T-cell count at the time of HIV diagnosis were significantly associated with clustering PWID individuals (all P< 0.001). In multivariate analyses, only recent IDU and higher CD4 T-cell count at the time of HIV diagnosis were significantly associated with clustering (P< 0.01). In addition, the proportion of PWID in clusters increased from 11.2% in 2010–2013 to 28.5% in 2018–2021 (P< 0.001). Nodes are colored by their reported PWID in darkred and reported non-PWID in blue. Conclusion We detected an increase in HIV genetic clusters among PWID in NC in recent years. Our results support the use of routine local molecular HIV surveillance to identify high priority clusters and offer prevention interventions for specific risk groups to prioritize limited public health resources. Disclosures Joseph J. Eron, MD, GSK: Advisor/Consultant|Merck: Advisor/Consultant.