title: Multiple introductions and onward transmission of non-pandemic HIV-1 subtype B strains in North America and Europe.
abstract: Most HIV-1 subtype B infections in North America and Europe seem to have resulted from the expansion of a single pandemic lineage (BPANDEMIC) disseminated from the United States (US). Some non-pandemic subtype B strains of Caribbean origin (BCAR) may have also reached North America and Europe, but their epidemiological relevance in those regions remains largely unknown. Here we analyze a total of 20,045 HIV-1 subtype B pol sequences from the US, Canada, and Europe, to estimate the prevalence and to reconstruct the spatiotemporal dynamics of dissemination of HIV-1 BCARstrains in those regions. We find that BCARstrains were probably disseminated from the Caribbean into North America and Europe at multiple times since the early 1970s onwards. The BCARstrains reached the US, Canada and at least 16 different European countries, where they account for a very low fraction (<5%) of subtype B infections, with exception of the Czech Republic (7.7%). We also find evidence of the onward transmission of BCARclades in the US, Canada, the Czech Republic, Germany, Italy, Spain and the UK, as well as short-distance spreading of BCARlineages between neighboring European countries from Central and Western Europe, and long-distance dissemination between the US and Europe.
authors.affiliation: Laboratório de AIDS e Imunologia Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Marina
authors.initials: M
authors.lastname: Cabello
authors.affiliation: Laboratorio de Organizacion y Evolucion del Genoma, Departamento de Ecologıa y Evolucion, Facultad de Ciencias-CURE, Universidad de la Republica, Montevideo, Uruguay.
authors.forename: Hector
authors.initials: H
authors.lastname: Romero
authors.affiliation: Laboratório de AIDS e Imunologia Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Bello