HIV-1 subtype B spread through cross-border clusters in the Balkans: a molecular analysis in view of incidence trends

Abstract

Objectives:To analyze phylogenetic relations and assess the role of cross-border clusters in the spread of HIV-1 subtype B across the Balkans, given the general trends of new HIV diagnoses in seven Balkan countries.Design:Retrospective phylogenetic and trend analysis.Methods:In-depth phylogenetic, phylodynamic and phylogeographic analysis performed on 2415 HIV-1 subtype B sequences from 1999 to 2019 using maximal likelihood and Bayesian methods. The joinpoint regression analysis of new HIV diagnoses by country and modes of transmission using 2004–2019 ECDC data.Results:Ninety-three HIV-1 Subtype B transmission clusters (68% of studied sequences) were detected of which four cross-border clusters (11% of studied sequences). Phylodynamic analysis showed activity of cross-border clusters up until the mid-2000s, with a subsequent stationary growth phase. Phylogeography analyses revealed reciprocal spread patterns between Serbia, Slovenia and Montenegro and several introductions to Romania from these countries and Croatia. The joinpoint analysis revealed a reduction in new HIV diagnoses in Romania, Greece and Slovenia, whereas an increase in Serbia, Bulgaria, Croatia and Montenegro, predominantly among MSM.Conclusion:Differing trends of new HIV diagnoses in the Balkans mirror differences in preventive policies implemented in participating countries. Regional spread of HIV within the countries of former Yugoslavia has continued to play an important role even after country break-up, whereas the spread of subtype B through multiple introductions to Romania suggested the changing pattern of travel and migration linked to European integration of Balkan countries in the early 2000s.

Transmitted HIV Drug Resistance in Bulgaria Occurs in Clusters of Individuals from Different Transmission Groups and Various Subtypes (2012–2020)

“…In contrast, CRF01_AE was found mostly in PWIDs and rarely in MMSCs. The differences in the prevalence of these subtypes among MMSC and PWIDs are most likely a consequence of their initial introduction into these groups, followed by rapid dissemination among these populations, as described in our previous studies [20][21][22]55,56]. This result is supported by our finding of transmission clusters containing sequences from people with different transmission risk behaviors.…”

Sociopolitical Diagnostic Tools to Understand National and Local Response Capabilities and Vulnerabilities to Epidemics and Guide Research into How to Improve the Global Response to Pathogens

“…Further, as phylogenetic research has demonstrated, viruses and thus pandemics spread from one country to another, with those countries that respond poorly acting as sources for new strains with mutations potentially affecting transmissibility, pathogenicity, or vaccine-induced protection, and potentially as sources of transmission to countries with more effective responses [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ] and to countries linked by the movement of commodities and people. Diagnostic tools to understand how to reduce such spread and how to optimize international cooperation in response to it are needed.…”

Cross-border Activities Associated With Pattern of Amphetamine-type Stimulants Usage Among Drug Users in Southwest of China

“…21 Population movement was an independent risk factor in determining the spread of disease especially new HIV infections, which evidence came from an increase in immigration to Europe associated with variations in distributions of HIV subtypes among cross-border clusters. 23 Migrants were more likely to use substance, because cross-border activities increased access to drugs and drug trafficking due to border stress, environmental risks and psychological factors in border areas. 24 It was nearly 14% using methamphetamine among ethnic minorities of Thailand's border due to easily accessible to illegal drugs.…”

“… 21 Population movement was an independent risk factor in determining the spread of disease especially new HIV infections, which evidence came from an increase in immigration to Europe associated with variations in distributions of HIV subtypes among cross-border clusters. 23 …”