title: HIV-1 molecular epidemiology in Guinea-Bissau, West Africa: origin, demography and migrations.
abstract: The HIV-1 epidemic in West Africa has been dominated by subtype A and the recombinant form CRF02_AG. Little is known about the origins and the evolutionary history of HIV-1 in this region. We employed Maximum likelihood and Bayesian methods in combination with temporal and spatial information to reconstruct the HIV-1 subtype distribution, demographic history and migration patterns over time in Guinea-Bissau, West Africa. We found that CRF02_AG and subsubtype A3 were the dominant forms of HIV-1 in Guinea-Bissau and that they were introduced into the country on at least six different occasions between 1976 and 1981. These estimates also corresponded well with the first reported HIV-1 cases in Guinea-Bissau. Migration analyses suggested that (1) the HIV-1 epidemic started in the capital Bissau and then dispersed into more rural areas, and (2) the epidemic in Guinea-Bissau was connected to both Cameroon and Mali. This is the first study that describes the HIV-1 molecular epidemiology in a West African country by combining the results of subtype distribution with analyses of epidemic origin and epidemiological linkage between locations. The multiple introductions of HIV-1 into Guinea-Bissau, during a short time-period of five years, coincided with and were likely influenced by the major immigration wave into the country that followed the end of the independence war (1963-1974).
authors.affiliation: Section of Molecular Virology, Department of Experimental Medical Science, Lund University, Lund, Sweden. joakim.esbjornsson@med.lu.se
authors.forename: Joakim
authors.initials: J
authors.lastname: Esbjörnsson
authors.forename: Mattias
authors.initials: M
authors.lastname: Mild
authors.forename: Fredrik
authors.initials: F
authors.lastname: Månsson
authors.forename: Hans
authors.initials: H
authors.lastname: Norrgren
authors.forename: Patrik
authors.initials: P
authors.lastname: Medstrand
mesh_terms: D000354:Africa, Western / Q000453:epidemiology; D001483:Base Sequence; D003710:Demography; D004641:Emigration and Immigration / Q000706:statistics & numerical data; D058872:Epidemics; D014644:Genetic Variation / Q000502:physiology; D006169:Guinea-Bissau / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology* / Q000235:genetics / Q000821:virology*; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D058974:Phylogeography; D011157:Population Dynamics