Phylodynamics analysis of HIV epidemic history in Belarus in 1987-2022

Abstract

This paper presents the first systematic molecular epidemiology study of the HIV epidemic in Belarus, an Eastern European country that, like much of Eastern Europe and including the Post-Soviet region, has been largely understudied in relation to HIV epidemics. HIV sequences collected nationwide between January 2018 and May 2022 were analyzed using phylogenetic and phylodynamic methods. The findings reveal two distinct epidemic waves spanning 1997-2005 and 2009-2018, each driven by different dominant modes of transmission. The study also identifies potential introductions and intra-country transmission routes, emphasizing the pivotal role of the capital city and eastern industrial hubs within Belarus in shaping the epidemic's trajectory. This work addresses an important gap in understanding HIV dynamics in Eastern Europe.

Keywords: Belarus; HIV; infectious diseases; molecular epidemiology; phylodynamics.

Figure 1

Left: Phylogenetically reconstructed between-country HIV-1 transmission network. Right: Inferred non-directional HIV intra-country transmission network. Largest transmission clusters are highlighted by circles. The displayed nodes may have multiplicity greater than one, but for simplicity, they are presented as single points.

Figure 2

Timed phylogeny of the Belarusian HIV sequences. Clades containing sequences from Svietlahorsk (cluster 2) and Salihorsk (cluster 3), as well as those likely corresponding to isolated HIV introductions, are highlighted in different colors.

Figure 3

Median estimates and the corresponding 95% highest posterior density (HPD) intervals of the effective infected population size $N_e$.

Figure 4

Median estimates and the corresponding 95% highest posterior density (HPD) intervals are presented in panel (A) for the effective reproduction number $R_e$ (orange), and in panel (B) for the becoming uninfectious rate $\delta$ (blue).