CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

913 HIV RISK INCREASES WITH POSITIVE TIES IN HIGHLY CONNECTED SOCIOSPATIAL PWID NETWORK Steven J. Clipman 1 , Shruti H. Mehta 1 , Aylur K.Srikrishnan 2 , Katie J. Zook 3 , Priya Duggal 1 , Shobha Mohapatra 2 , Shanmugam Saravanan 2 , Nandagopal Paneerselvam 2 , Muniratnam S. Kumar 2 , Elizabeth Ogburn 1 , Allison M. McFall 1 , Gregory M. Lucas 3 , Carl A. Latkin 1 , Sunil S. Solomon 3 1 Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA, 2 YR Gaitonde Center for AIDS Research and Education, Chennai, India, 3 Johns Hopkins University School of Medicine, Baltimore, MD, USA Background: People who inject drugs (PWID) bear high HIV and hepatitis C virus (HCV) burden and account for some of the most explosive epidemics globally. While individual risk factors for infection are well understood, less is known about network and spatial factors. Moreover, network studies have been limited by focusing on immediate ties (egocentric network) rather than the broader sociometric/spatial networks. Methods: 2,512 PWID were recruited via a chain referral method in 2017-19 in New Delhi, India. An index initiated sampling and was asked to recall who they injected with in the past month and was provided referrals for those partners (index’s egocentric network). Similarly, each recruit named and recruited their recent injection network (recruit’s egocentric network and index’s sociometric network). Participant biometrics identified duplicates and cross-network linkages. All completed a survey, provided blood and information on injection locations; these data were used to generate spatial networks. Sociometric injection networks were created and analyzed using bespoke Python code. Individual and network-level factors were analyzed for associations with prevalent HIV infection; machine learning was used to nominate predictors. Results: Median age was 26; 99.1%were male. HIV prevalence at baseline was 36.9% and 7.4%were virally suppressed; HCV antibody prevalence was 65.1%. The networks of 8 of 11 indexes merged into one network (Figure). Average degree (number of injection partners) was 2.1 (range: 0–47), network diameter was 39 and average path length was 14. Of 928 HIV-positive participants at baseline, 64.6%were directly connected with at least one other HIV-positive PWID. Of 1,634 HCV-positive participants at baseline, 86.8%were directly connected with at least one other HCV-positive PWID. The odds of HIV increased with each additional HIV-infected ego in a network (OR=1.21) and injecting at a specific hotspot (OR=1.86), factors that were independent of individual needle sharing (OR=1.89) and injection frequency (OR=1.36; all p<0.001). Conclusion: These are among the first data to comprehensively characterize the complete sociometric injection network of PWID in an urban setting. We observed a highly connected network structure where HIV and HCV prevalence were associated with network connections and spatial overlap after adjusting for other predictors. These data have implications for the success of network- based prevention/treatment strategies.

(aOR:1.37; 95%CI:1.16-1.61). In sensitivity analyses examining factors associated with membership in a cluster with a seroconverter also identified lack of religious affiliation as an independent predictor (aOR:1.56; 95%CI:1.02-2.41) in addition to age (P=0.03) and viremia (P=0.047). Conclusion: Molecular epidemiology can be applied to characterize HIV transmission networks. Clustering was associated with younger age group, , and lack of viral suppression. These findings reinforce the importance of enhanced targeted HIV testing programs and scale-up of ART to increase viral suppression in persons living with HIV. 912 ASSOCIATIONS BETWEEN PHYLOGENETIC TRANSMISSION CLUSTERS AND HLA PROFILES IN MEXICO Sanjay R. Mehta 1 , Santiago Avila-Rios 2 , Matthew Strain 1 , Humberto Valenzuela Ponce 2 , Maribel Soto-Nava 2 , Margarita Matías-Florentino 2 , Alicia Piñeirúa 3 , Florentino Badial-Hernandez 3 , Andrea Gonzalez Rodriguez 3 , Davey M. Smith 1 , Gustavo Reyes-Terán 2 , Antoine Chaillon 1 1 University of California San Diego, La Jolla, CA, USA, 2 National Institute of Respiratory Diseases, Mexico City, Mexico, 3 Clinica Especializada Condesa, Mexico City, Mexico Background: Class I Human leukocyte antigen (HLA-I) is a major driver of HIV evolution, both at the individual and population level, promoting HIV adaptation to cellular immune responses. The extent to which HIV adaptation to HLA-I plays a role in transmission is not well understood. Here, we examined associations between HLA-I profiles and HIV transmission in the Mexico City HIV epidemic. Methods: 1,049 HIV-1 subtype B pol sequences sampled between 2016 and 2018 from unique, HLA-I-typed individuals in Mexico City were analyzed. Genetic transmission networks were inferred using HIV-TRACE, establishing putative transmission linkage below a genetic distance threshold of 1.5%. High- resolution HLA profiles were determined using next-generation sequencing. Newman’s assortativity coefficients were estimated using igraph. Fisher’s exact tests were used to determine whether there was enrichment of specific HLA alleles in clustering vs. non-clustering individuals. P-groups, known to bind similar peptides, were used for HLA-match analyses. Results: 286/1,049 (27%) individuals were genetically linked with at least one other person, forming 120 clusters (range: 2-8 individuals). All but 2 clustering individuals were male. Clustering and non-clustering individuals did not differ by age, baseline CD4 or HIV RNA level. HLA-C*02:02 was enriched in clustering individuals (p=0.02). Overall 30% (86/286) of clustering individuals shared ≥2 HLA-I P-groups/alleles in any of the three loci (Fig. 1A), and 26 had fully concordant (i.e. two matching alleles) HLA-A (13; 4.5%), HLA-B (2; 0.7%) or HLA-C (11; 3.8%) loci (Fig. 1B). Rates of HLA-I allelic concordance among clustering individuals were significantly higher than among the full cohort at all three loci (p<0.01). Conclusion: HLA-I haplotypes were significantly more concordant than expected among clustering individuals in Mexico City. These findings suggest that viral adaptations may enhance transmissibility. However, further work is needed to determine if this increased concordance is due to viral factors (i.e. adaptation) or sociodemographic factors (i.e. ancestry, racial assortativity).

Poster Abstracts

CROI 2020 342