32nd International Dynamics & Evolution of Human Viruses

LEVERAGING ADVANCED PHYLOGENETIC APPROACHES TO UNDERSTAND THE HIV-1 TRANSMISSION AND EVOLUTIONARY DYNAMICS IN SERBIA

Not scheduled

20m

Abbaye de Royaumont, Asnières-sur-Oise, France

Poster Transmission dynamics & clusters Virtual posters

Speaker

Dr Marina Siljic (Institute of Microbiology and Immunology, Department of Virology, Faculty of Medicine, University of Belgrade, Serbia)

Description

Background:
This study was aimed to understand the evolutionary and transmission dynamics of HIV-1 epidemic in Serbia and to reveal the socio-demographic and clinical factors that shaped the expansion of phylogenetic transmission clusters. The dataset of 720 HIV-1 pol sequences isolated from both newly diagnosed and therapy experienced healthcare clients, between 1997 and the end of 2023, was used.
Methods:
Maximum Likelihood (ML) phylogenetic trees were constructed using PhyML 3.0 software. In order to estimate effective reproductive number (Re) phylodynamic analysis was performed in the BEAST 2.7 software package. Transmission clusters were defined based on both genetic distance and bootstrap support value. For each of the sequences within the identified transmission cluster, 5 to 10 mostly similar sequences were retrieved from GenBank based on BLAST analysis and included in the tree reconstruction. Transmission clusters were further evaluated using latent class analyses (LCA) in R software to determine association of clusters with underlying epidemiological/clinical characteristics.
Results:
Transmission cluster analysis revealed the presence of 25 transmission clusters. Of those 7/25 transmission clusters were found intermixed with sequences retrieved from BLAST analysis, sampled in neighbouring countries, and could be considered as cross-border rather than local. Eight of 25 local transmission clusters were found with Re higher than 1 in the latest years. LCA revealed the presence of five latent classes. Of note, one latent class that encompassed patients whose viral sequences were grouped within transmission clusters was characterized by male patients reporting sex with men as risk for acquiring HIV infection, predominantly of younger age, presenting in early CDC stage, and with considerable prevalence of confections (HBV) and other sexual transmitted illnesses (STIs).
Conclusions:
Transmission dynamics of HIV spread in Serbia is linked to transmission clusters formation with strong potential for further expansion, connected to young MSM with concomitant HBV and other STIs as the main target group for planning structured preventive policies.