CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

Background: Migrants account for nearly 30% of all new diagnoses of HIV infection in Italy in the last years. Aim of this study was to evaluate the characteristics of HIV-1 molecular transmission clusters (MTCs) among natives and foreign individuals diagnosed between 1998 and 2018 enrolled in the ICONA cohort. Methods: Phylogenetic analyses were performed on HIV-1 pol sequences (seq) to characterise subtypes (Neighbor Joining method, 1000 replicates) and identify MTCs, divided into small (SMTCs, 2-3 seq), medium (MMTCs, 4–9 seq) and large (LMTCs, ≥10 seq). MTCs were first deduced by the HIV-TRACE tool (genetic distance ≤0.01). The robustness of MTCs was further tested using the Maximum Likelihood method, using MEGA6 software. Factors associated with MTCs were evaluated using logistic regression. Results: Among 3,499 drug-naïve participants in the ICONA cohort (2,804 natives; 695 migrants), 726 (20.8%; 644 natives, 82 migrants) were involved in 228 MTC, including 6 LMTCs (N=140 subjects), 36 MMTCs (N=184) and 186 SMTCs (N=402), respectively. Subjects involved in MTCs were prevalently native (88.7% vs 77.8%, p<0.001), male (94.3% vs 78.9%, p<0.001) and MSM (74.7% vs 45.0%, p<0.001), younger (median [IQR] yrs: 32 [27–40] vs 38 [31–46], p<0.001), more recently diagnosed (median [IQR] yrs: 2012 [2009–2014] vs 2011 [2007–2014], p<0.001), and with higher CD4 count compared to subjects out of MTCs (median [IQR]: cells/mm 3 : 459 [322–624] vs 353 [177–523], p<0.001) (Table). HIV-1 non-B subtype was found in 51 MTCs (22.4%); of note, non-B infections involved in MTCs were more commonly found in natives (N=47, 92.2%) than in foreigners (N=4, 7.8%). Logistic regression confirmed that factors such as Italian origin, being MSM, younger age, more recent diagnosis and higher CD4 count were significantly associated with MTCs (Table). The presence of both natives and foreigners was found in 66.7% of LMTCs, 33.3% of MMTCs and 23.1% of SMTCs. By focusing on migrants, they contributed for 14.4% to SMTCs, 7.6% to MMTCs and 7.1% to LMTCs, respectively. The 24 migrants involved in LMTCs and MMTCs were mainly from Central/South America or other European countries. Conclusion: HIV-1 newly diagnosed subjects are involved in several MTCs in the last two decades in Italy. Clustering transmission, especially for large clusters, is prevalently driven by natives, mainly MSM and frequently infected with HIV-1 non-B subtype. Our findings can contribute to monitoring of the HIV epidemic and guiding the public health response.

Center of the University of Munich, Munich, Germany, 8 Technical University of Munich, Munich, Germany, 9 University Medical Center Freiburg, Breisgau, Germany, 10 University of Cologne, Koln, Germany, 11 University Hospital Hamburg–Eppendorf, Hamburg, Germany Background: The presence of HIV-1 non-B subtypes in Germany has been increasing in recent years and is commonly attributed to migration from non- European countries. We combined molecular epidemiology and geospatial data to explore dynamics of HIV-1 non-B subtypes in Germany, before and after the European migrant crisis 2015. Methods: Sociodemographic, geographic and HIV-1 pol sequence data were obtained from individuals who accessed care at seven University Hospitals (Bonn, Cologne, Freiburg, Frankfurt, Hamburg, Hannover, Munich) in Germany, between 2001 and 2018. Phylogenetic and genetic network analyses were performed to infer putative transmission links (genetic distance ≤1.5%). Individuals‘ origins were grouped into six regions: Western Europe and other high resource countries; Eastern Europe; North Africa and the Middle East; sub- Saharan Africa; Latin America and the Caribbean; and Asia. Results: We included data from 3,110 HIV-1 infected individuals. The overall proportion of the non-B subtypes increased from 27% (673/2,490) before January 2015 to 31.5% (195/620) after 2015 (subtype G 7.4%; 184/2,490 before 2015 vs. 9.5%; 59/620 after). This was particularly driven by the year 2017, where non-B subtypes made up 39.4% of new HIV diagnoses. The proportion of non-B infected individuals, originating from Eastern Europe [8.9% (254/673) to 13.3% (60/195), p= 0.027], and the North Africa and Middle East region [1.34% (9/673) to 5.6% (11/195), p< 0.001] increased significantly after 2015. However, there were only three new non-B diagnoses after 2015 among individuals from the top 5 countries of origin of the 2015 immigrants (i.e. Syria, Kosovo, Afghanistan, Albania, Iraq). Of the 868 non-B HIV infected individuals, 119 (13.7%) were genetically linked, forming 42 transmission clusters (size 2-19 sequences) with heterosexual risk (36.1%; 43/119) and injection drug use (20.1%; 24/119) being predominant. There was an increase in genetically linked men who have sex with men (MSM) with two male only clusters before 2015 and the emergence of six more male only clusters (including 9/18 males, of whom 8/9 originating from Eastern Europe) after 2015 (Figure 1A&B). Conclusion: The proportion of HIV-1 non-B diagnoses increased after 2015, particularly driven by individuals originating from Eastern Europe, North Africa, and Middle East. However, the number of new diagnoses among migrants originating from the top 5 countries of the European migrant crisis was minimal.

Poster Abstracts

920 EVALUATION OF HIV TRANSMISSION CLUSTERS AMONG NATIVES AND FOREIGNERS LIVING IN ITALY Maria M. Santoro 1 , Lavinia Fabeni 1 , Patrizia Lorenzini 2 , Stefano Rusconi 3 , Nicola Gianotti 4 , Andrea Costantini 5 , Loredana Sarmati 6 , Andrea Antinori 2 , Francesca Ceccherini Silberstein 1 , Antonella D'Arminio Monforte 7 , Annalisa Saracino 8 , Enrico Girardi 2 , for the Icona Foundation Study Cohort 1 University of Rome Tor Vergata, Rome, Italy, 2 Lazzaro Spallanzani National Institute for Infectious Diseases, Rome, Italy, 3 Luigi Sacco University Hospital, Milan, Italy, 4 San Raffaele Scientific Institute, Milan, Italy, 5 Marche Polytechnic University, Ancona, Italy, 6 Hospital of Rome Tor Vergata, Rome, Italy, 7 University of Milan, Milan, Italy, 8 University of Bari, Bari, Italy

CROI 2020 345