title: Phylogenetic analysis of the Latvian HIV-1 epidemic.
abstract: The Latvian HIV-1 outbreak among intravenous drug users (IDUs) in 1997-1998 involved subtype A1. To obtain a more complete picture of the Latvian HIV-1 epidemic, 315 HIV-1-infected patients diagnosed in 1990-2005 representing different transmission groups and geographic regions were phylogenetically characterized using env V3 and gag p17 sequences. Subtypes A1 and B infections were found in 76% and 22% of the patients, respectively. The subtype A1 sequences formed one large cluster, which also included sequences from other parts of the former Soviet Union (FSU), whereas most subtype B sequences formed three distinct clusters. We estimated that subtype A1 was introduced from FSU around 1997 and initially spread explosively among IDUs in Riga. A recent increase of heterosexually infected persons did not form a separate subepidemic, but had multiple interactions with the IDU epidemic. Subtype B was introduced before the collapse of the Soviet Union and primarily has spread among men who have sex with men.
authors: Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden.
authors: Dace
authors: D
authors: Balode
authors: Helena
authors: H
authors: Skar
authors: Mattias
authors: M
authors: Mild
authors: Tatjana
authors: T
authors: Kolupajeva
authors: Andris
authors: A
authors: Ferdats
authors: Baiba
authors: B
authors: Rozentale
authors: Thomas
authors: T
authors: Leitner
authors: Jan
authors: J
authors: Albert
mesh_terms: D058872:Epidemics; D005260:Female; D015699:HIV Envelope Protein gp120 / Q000235:genetics*; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics; D006801:Humans; D007844:Latvia / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012725:Sexual Behavior
chemical_list: D015699:HIV Envelope Protein gp120