CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

183 REVEALING THE MOLECULAR EPIDEMIOLOGY OF THE COLOGNE, GERMANY, HIV EPIDEMIC Melanie Stecher 1 , Martin Hoenigl 2 , Joerg Janne Vehreschild 1 , Clara Lehmann 3 , Gerd Fätkenheuer 3 , Rolf Kaiser 1 , Sanjay R. Mehta 2 , Antoine Chaillon 2 1 Univ of Cologne, Cologne, Germany, 2 Univ of California San Diego, San Diego, CA, USA, 3 Cologne Univ Hosp, Cologne, Germany

Background: By inferring potential transmission links between risk groups, demographic sub-populations, and geography, one may better understand the drivers of spread locally, and the links between epidemics outside the region. This study focused on the HIV epidemic in Cologne, the city with the highest rate of new HIV infections in Germany. Methods: Phylogenetic and network analyses were performed to infer putative relationships between HIV-1 partial pol sequences from unique individuals receiving care at the University Hospital of Cologne, Germany. We applied a computationally efficient network-based approach to analyze relationships between all publicly available HIV sequences found in the Los Alamos National Laboratory HIV Sequence database. We also screened all sequences from Cologne for drug resistance mutations using the Calibrated population resistance tool. Results: The sampled population was predominantly male (80%). The most important risk factor for HIV infection (54.8% of the study population) was men reporting sex with men (MSM, 54.8%), while only 3.6% reported injection drug use as their main risk factor. 248/1,507 (16.5%) sequences linked with at least one other sequence, forming 83 transmission clusters, ranging in size from 2 to 10 sequences (Figure). Clustering individuals were significantly more likely to be younger (median age 36 vs 40, p<0.001), men (90.2% vs 78.4%, p<0.001), reporting MSM contact as main risk factor (70.6% vs 51.7%, p<.001). Drug resistance screening showed that 24.4% and 26.6% of sequences harbored at least one Nucleoside or Non-Nucleoside Reverse Transcriptase Inhibitors (NRTI/NNRTI) mutation respectively. Among clustering sequences, we found 10 sequences with K103N mutations (90% fromMSM), 6 of them shared by linked sequences. By combining local data with 119,222 publicly available HIV polymerase sequences, we found a total of 78 clusters (91% subtype B) that included both sequences from Cologne and other regions in Germany (64 clusters, 82%) or predominantly European Countries. Conclusion: In this analysis of the HIV-1 epidemic in Cologne, the city with the highest HIV incidence in Germany, we found multiple links between this epidemic and those across Germany and around the world. These results highlight the pitfalls of focusing prevention efforts and monitoring on specific risk groups or specific locales, and not taking into consideration the overall HIV epidemic.

Poster and Themed Discussion Abstracts

184 STRUCTURE OF HIV-1C TRANSMISSION NETWORK IN SOUTHERN BOTSWANA, 2016 Vlad Novitsky 1 , Sikhulile Moyo 2 , Melissa Zahralban-Steele 1 , Baitshepi Mokaleng 2 , Dorcas Maruapula 2 , Mary F. McLane 1 , Kathleen Wirth 1 , Lisa A. Mills 3 , Simani Gaseitsiwe 2 , Max Essex 1 1 Harvard Univ, Boston, MA, USA, 2 Botswana Harvard AIDs Rsr Inst Partnership, Gaborone, Botswana, 3 CDC Botswana, Gaborone, Botswana Background: The HIV epidemic in Southern Africa is caused by multiple circulating lineages of HIV-1C. The transmission dynamics of the HIV-1C epidemic are still poorly understood. Methods: The HIV-1C epidemic was broken down into phylogenetically distinct viral lineages using 1,793 near full-length HIV-1C genome sequences. A total of 1,349 near full- length HIV-1C genome sequences included 684 from 4 large Botswana communities-Gaborone, Mochudi, Molepolole and Lobatse - and 665 sequences from 15 small communities, primarily in the southern region. Overall, 94% of Botswana sequences (n=1,269) originated from the southern region. The circulating HIV-1C lineages were analyzed by gender and age distributions, HIV-1 RNA levels and proportion of individuals on ART. Results: The proportion of Botswana sequences in clusters was 54% (95% CI 51.3–56.7%). Cluster analysis was limited to 189 clusters with predominantly (75%) Botswana sequences (including 5 mixed clusters) with 2 to 49 sequences per cluster. Cluster composition analysis revealed that 24% (95% CI 18–31%) of HIV-1C lineages were found only in small communities, 27% (95% CI 21–34%) only in large communities, and 49% (95% CI 41–56%) in both small and large communities. The median (IQR) number of circulating viral lineages per community was 15 (7–25) in small and 44 (40–57) in large communities (p<0.01). Within circulating HIV-1C lineages, females (median 33 y.o.; IQR 28–39 y.o.) were approximately nine years younger than males (median 42 y.o.; IQR 35–48 y.o.; p<0.0001). Recently infected individuals (n=14) were found in 12 of 189 clusters. Clusters with recent HIV infections had higher HIV-1 RNA (median (IQR) 4.4 (4.1–4.6) vs. 3.7 (2.7–4.6) log10 copies/mL; p<0.05); had lower proportions of individuals on ART (p<0.005); and tended to be younger (p<0.1). No differences between clustered (n=728) and non-clustered (n=621) Botswana individuals were found by age and gender distributions, levels of HIV-1 RNA, or proportion of individuals on ART (p-values n/s). Conclusion: The analysis revealed the structure of HIV transmission networks in southern Botswana communities using near full-length HIV-1C genome sequences. About half of circulating viral lineages were unique for either small or large communities. Within circulating HIV-1C lineages, females were about 9 years younger than males. Clusters with recent infections had higher HIV-1 RNA loads and lower proportions of individuals on ART, and seemed to be younger.

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CROI 2017