Phylogenetic analysis of human immunodeficiency virus type 2 group B

• Main Authors: Eleonora Cella, Alessandra Lo Presti, Marta Giovanetti, Carla Veo, Alessia Lai, Giordano Dicuonzo, Silvia Angeletti, Marco Ciotti, Gianguglielmo Zehender, Massimo Ciccozzi
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2016-01-01
• Series: Journal of Global Infectious Diseases
• Subjects: Evolution; Group B; human immunodeficiency virus type 2; phylogeny; phylogeographic analysis
• Online Access: http://www.jgid.org/article.asp?issn=0974-777X;year=2016;volume=8;issue=3;spage=108;epage=114;aulast=Cella

Context: Human immunodeficiency virus type 2 (HIV-2) infections are mainly restricted to West Africa; however, in the recent years, the prevalence of HIV-2 is a growing concern in some European countries and the Southwestern region of India. Despite the presence of different HIV-2 groups, only A and B Groups have established human-to-human transmission chains. Aims: This work aimed to evaluate the phylogeographic inference of HIV-2 Group B worldwide to estimate their data of origin and the population dynamics. Materials and Methods: The evolutionary rates, the demographic history for HIV-2 Group B dataset, and the phylogeographic analysis were estimated using a Bayesian approach. The viral gene flow analysis was used to count viral gene out/in flow among different locations. Results: The root of the Bayesian maximum clade credibility tree of HIV-2 Group B dated back to 1957. The demographic history of HIV-2 Group B showed that the epidemic remained constant up to 1970 when started an exponential growth. From 1985 to early 2000s, the epidemic reached a plateau, and then it was characterized by two bottlenecks and a new plateau at the end of 2000s. Phylogeographic reconstruction showed that the most probable location for the root of the tree was Ghana. Regarding the viral gene flow of HIV-2 Group B, the only observed viral gene flow was from Africa to France, Belgium, and Luxembourg. Conclusions: The study gives insights into the origin, history, and phylogeography of HIV-2 Group B epidemic. The growing number of infections of HIV-2 worldwide indicates the need for strengthening surveillance.