Tracing the HIV-1 subtype B mobility in Europe: a phylogeographic approach.
BACKGROUND
The prevalence and the origin of HIV-1 subtype B, the most prevalent circulating clade among the long-term residents in Europe, have been studied extensively. However the spatial diffusion of the epidemic from the perspective of the virus has not previously been traced.


RESULTS
In the current study we inferred the migration history of HIV-1 subtype B by way of a phylogeography of viral sequences sampled from 16 European countries and Israel. Migration events were inferred from viral phylogenies by character reconstruction using parsimony. With regard to the spatial dispersal of the HIV subtype B sequences across viral phylogenies, in most of the countries in Europe the epidemic was introduced by multiple sources and subsequently spread within local networks. Poland provides an exception where most of the infections were the result of a single point introduction. According to the significant migratory pathways, we show that there are considerable differences across Europe. Specifically, Greece, Portugal, Serbia and Spain, provide sources shedding HIV-1; Austria, Belgium and Luxembourg, on the other hand, are migratory targets, while for Denmark, Germany, Italy, Israel, Norway, the Netherlands, Sweden, Switzerland and the UK we inferred significant bidirectional migration. For Poland no significant migratory pathways were inferred.


CONCLUSIONS
Subtype B phylogeographies provide a new insight about the geographical distribution of viral lineages, as well as the significant pathways of virus dispersal across Europe, suggesting that intervention strategies should also address tourists, travellers and migrants.
Paraskevis
Dimitrios
D
Katholieke Universiteit Leuven, Rega Institute for Medical research, Minderbroederstraat 10, B-3000 Leuven, Belgium. dparask@cc.uoa.gr
Pybus
Oliver
O
Magiorkinis
Gkikas
G
Hatzakis
Angelos
A
Wensing
Annemarie Mj
AM
van de Vijver
David A
DA
Albert
Jan
J
Angarano
Guiseppe
G
Asjö
Birgitta
B
Balotta
Claudia
C
Boeri
Enzo
E
Camacho
Ricardo
R
Chaix
Marie-Laure
ML
Coughlan
Suzie
S
Costagliola
Dominique
D
De Luca
Andrea
A
de Mendoza
Carmen
C
Derdelinckx
Inge
I
Grossman
Zehava
Z
Hamouda
Osama
O
Hoepelman
Im
I
Horban
Andrzej
A
Korn
Klaus
K
Kücherer
Claudia
C
Leitner
Thomas
T
Loveday
Clive
C
Macrae
Eilidh
E
Maljkovic-Berry
I
I
Meyer
Laurence
L
Nielsen
Claus
C
Op de Coul
Eline Lm
EL
Ormaasen
Vidar
V
Perrin
Luc
L
Puchhammer-Stöckl
Elisabeth
E
Ruiz
Lidia
L
Salminen
Mika O
MO
Schmit
Jean-Claude
JC
Schuurman
Rob
R
Soriano
Vincent
V
Stanczak
J
J
Stanojevic
Maja
M
Struck
Daniel
D
Van Laethem
Kristel
K
Violin
M
M
Yerly
Sabine
S
Zazzi
Maurizio
M
Boucher
Charles A
CA
Vandamme
Anne-Mieke
AM
D016000:Cluster Analysis; D016358:Contact Tracing / Q000379:methods*; D005060:Europe / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007557:Israel / Q000453:epidemiology; D017720:Molecular Epidemiology; D010802:Phylogeny; D017422:Sequence Analysis, DNA