Using phylogenetic analysis to trace HIV-1 migration among western European injecting drug users seroconverting from...

Area of Science:

• Epidemiology
• Virology
• Public Health

Background:

• Understanding the transmission dynamics of HIV among injecting drug users (IDU) is crucial for effective public health interventions.
• Previous studies have indicated geographical variations in HIV epidemics, but detailed phylogenetic reconstructions are needed to understand transmission pathways.

Purpose of the Study:

• To reconstruct the epidemiological relationships of HIV epidemics among injecting drug users (IDU) across Western Europe.
• To identify genetic signatures and transmission patterns of HIV strains in different European regions over time.

Main Methods:

• Phylogenetic analysis of HIV env V3 sequences from 145 IDU who seroconverted between 1984 and 1997.
• Examination of epidemiological data and conserved genetic patterns, such as the GGC codon, characteristic of Northern European IDU.

Main Results:

• Distinct subpopulations of genetically related HIV strains were observed in Italy, France, Scotland, and Spain, contrasting with the Netherlands, Austria, and Switzerland.
• Evidence suggests multiple introductions of HIV in the latter group of countries, while Edinburgh showed a dominant GGC strain over 12 years.
• An initial geographical separation of GGC (north-western Europe) and non-GGC (south-western Europe) viruses has diminished, likely due to inter-population virus exchange.

Conclusions:

• The study highlights the complex epidemiological landscape of HIV among IDU in Western Europe, with varying introduction events and transmission patterns.
• The fading geographical separation of HIV strains indicates increasing interconnectedness of IDU populations and potential for wider dissemination.
• Phylogenetic analysis provides valuable insights into HIV transmission networks, informing targeted prevention and control strategies for IDU.