CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

yielded 39 priority clusters (698 members) with 187 Prompt cases (4.8 vs. 1.6 Prompt cases/cluster in non-priority clusters). Conclusion: We detected a high rate of clustering among recent diagnoses with frequent involvement of past diagnoses. Harnessing longitudinal VL and sequence data allows for timely detection and monitoring of such clusters. Clusters with rapid growth and high network connectivity with past diagnoses without viral suppression can be prioritized for intensified care re-engagement and retention support.

1 University of California San Diego, San Diego, CA, USA, 2 Harvard University, Cambridge, MA, USA, 3 Los Angeles County Department of Public Health, Los Angeles, CA, USA Background: Successful public health action combatting HIV relies on navigation through the HIV continuum of care: timely diagnosis of infection followed by linkage to care and initiation of antiretroviral therapy to achieve and maintain suppression of viral replication. Molecular epidemiology can identify rapidly growing HIV genetic transmission clusters. How these clusters relate to the care continuum has not been previously characterized. Methods: We performed a population-based retrospective study on HIV/ AIDS surveillance data from 5226 adult living with HIV, had a reported HIV pol sequence, resided in Los Angeles County, and were diagnosed between January 2010 through December 2014 with laboratory data reported through 2016. An HIV genetic transmission clusters was constructed using HIV-TRACE based on these pol sequences using a pairwise genetic distance threshold of 0.015 substitutions/site. We characterized cluster growth as the number of cases added to a cluster in the previous year divided by the number of cases in the cluster. Separate Cox proportional hazard models assessed the time to each event along the care continuum and gamma frailty models accounted for heterogeneity between genetic transmission clusters. Results: Of the cases linked to care, 92% achieved viral suppression and 26% experienced post-suppression viral rebound. Median time from diagnosis to suppression was six months (IQR 4-13). Contrary to expectation, there were no differences in time to these events among individuals in clusters with different growth dynamics. However, upon achieving viral suppression, cases in high growth clusters were less likely to rebound (Hazard Ratio 0.83, p=0.011) compared with cases in low growth clusters. Heterogeneity due to cluster membership in the timing to each of event in the care continuumwas highly significant (p<0.001), even after adjusting for transmission risk and demographics. Conclusion: Combining molecular epidemiology and HIV surveillance approaches, we characterized the relationship between the HIV transmission network and the rates of linkage to care, viral suppression, and post-suppression viral rebound. Individuals within the same transmission cluster have similar trajectories through the HIV care continuum. These findings suggest molecular epidemiology can assist public health officials in identifying clusters of individuals who may benefit from assistance navigating the HIV care continuum. 911 SOCIODEMOGRAPHIC FACTORS ASSOCIATED WITH HIV CLUSTERING ACROSS BOTSWANA COMMUNITIES Sikhulile Moyo 1 , Kara Bennett 2 , Simani Gaseitsiwe 1 , Melissa Zahralban-Steele 3 , Tapiwa Nkhisang 3 , Jean Leidner 3 , Dorcas Maruapula 1 , Molly Pretorius Holme 3 , Etienne Kadima 1 , Tendani Gaolathe 3 , Kathleen Wirth 3 , Joseph Makhema 1 , Max Essex 3 , Shahin Lockman 3 , Vlad Novitsky 3 1 Botswana Harvard AIDS Institute Partnership, Gabarone, Botswana, 2 Bennett Statistical Consulting, Inc, New York, NY, USA, 3 Harvard T.H. Chan School of Public Health, Boston, MA, USA Background: Understanding HIV transmission networks is important for intervention programming. However, factors associated with molecular HIV clusters in southern Africa are not well-studied. We sought to identify independent predictors of being part of a molecular HIV cluster using data from HIV-positive persons enrolled in a large community-randomized HIV prevention trial in Botswana. Methods: The Botswana Combination Prevention Project was conducted in 30 communities across Botswana in 2013-2018. At study enrollment, near-full length HIV-1 genome sequences were obtained (from RNA or DNA) from HIV- positive persons and analyzed for genetic relatedness. We defined an inferred molecular HIV cluster (transmission network) as a phylogenetically distinct viral lineage giving rise to a monophyletic subtree of the overall phylogeny with bootstrap support of splits >0.80. Multivariate logistic regression models (adjusted for clustering) were constructed using a backwards elimination procedure to select from pre-specified set of candidate socio-demographic and behavioral variables. Results: Among the 6,536 HIV-positive BCPP participants, sequences were obtained from 4,009 (61%) and 1,904 (46% of 4,009) were in one or more of the 850 unique molecular HIV clusters identified. The majority of cluster members were female (73%) with a median (IQR) age of 40 years (33, 48). Factors associated with being in a cluster included: age 25-34 years (aOR:1.29; 95%CI:1.01–1.65), transactional sex (aOR:1.51; 95%CI:1.09-2.10), and viremia

Poster Abstracts

909 DO PARTNER SERVICES INITIATED FROM MOLECULAR CLUSTERS YIELD NEW OR VIREMIC HIV CASES? John A. Schneider 1 , Christina S. Hayford 2 , Irina Tabidze 3 , Joel O. Wertheim 4 , Camden Hallmark 5 , Aditya Khanna 1 , Patrick Janulis 2 , David Kern 3 , Ethan Morgan 2 , Jonathan Ozik 6 , Anna Hotton 1 , Kayo Fujimoto 7 , Richard D'Aquila 2 , Nanette Benbow 2 1 University of Chicago, Chicago, IL, USA, 2 Northwestern University, Chicago, IL, USA, 3 Chicago Department of Public Health, Chicago, IL, USA, 4 University of California San Diego, San Diego, CA, USA, 5 Houston Health Department, Houston, TX, USA, 6 Argonne National Lab, Chicago, IL, USA, 7 University of Texas at Houston, Houston, TX, USA Background: Molecular HIV surveillance is increasingly utilized as an approach to identify new HIV diagnoses linked to clusters. Health departments employ partner services to interview people newly diagnosed with HIV—index clients— to elicit named sexual/injection drug-use partners. We examined whether the yield of new diagnoses or viremic named partners varied by molecular cluster (versus not in a cluster) when attempting to interview index clients with HIV pol sequences. Methods: We matched and analyzed HIV surveillance (including HIV pol sequences) and partner services data from HIV diagnoses in Chicago from 2012 through 2016 from the Chicago Department of Public Health. We constructed molecular clusters using HIV-TRACE at a pairwise genetic distance threshold 0.5%. We compared the normalized proportion of partners reported by index clients who were a new HIV diagnosis or recently had detectable viremia (‘yield’ of partner services) in a molecular cluster vs. those whose HIV sequences did not cluster. Results: Of 2,404 newly diagnosed index clients, 1,015 (42%) had HIV sequence data available and partner services initiated within 12 months of diagnosis. Of these, 336 (33%) had HIV pol sequences that clustered and 96 (29%) of them named at least one partner. The average age of index clients in clusters was 28, 47%were Black, 29% Latinx, 6% female and 89%men who have sex with men. Of the 539 named partners, 162 (36.6%) were linked to indexes in a cluster and of those 20%were either new diagnoses or viremic. There was no statistically significant difference in the yield of new diagnoses or viremic partners linked to index clients in a cluster versus not in a cluster (RR 1.54 (0.10-2.38); p=0.051). Conclusion: Partner services that were initiated from the subset of index clients whose HIV sequences are in a molecular cluster yielded similar new HIV case finding or identification of those with viremia as index clients not in clusters. Future research should examine the yield among growing molecular clusters as well as partner services originating frommolecular clusters that identify HIV clients co-infected with syphilis and other STIs, and by consideration of compositions by transmission categories in molecular clusters. 910 THE RELATIONSHIP BETWEEN THE HIV TRANSMISSION NETWORK AND CARE CONTINUUM IN LA COUNTY Adiba Hassan 1 , Victor De Gruttola 2 , Yunyin W. Hu 3 , Zhijuan Sheng 3 , Kathleen Poortinga 3 , Joel O. Wertheim 1

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