Origin and Evolutionary History of HIV-1 Subtype B in Cuba

Abstract

INTRODUCTION Cuba's HIV epidemic is characterized by high genetic diversity, with circulation of several subtypes and recombinant forms. Earlier studies described a predominance of subtype B in the HIV-positive population, but these studies did not take into account patients' epidemiologic history.OBJECTIVE Clarify the origin and phylodynamics of HIV-1 subtype B in the Cuban epidemic. METHODSWe analysed phylogenetic relationships among 120 sequences (from different geographic origins) of the pol gene in HIV-1 subtype B isolates from Cuban patients diagnosed from 1987 through 2012. Time of HIV-1 subtype B introduction and viral evolutionary rate were determined using a Bayesian coalescent method. RESULTSBased on phylogenetic relationships, subtype B was introduced into Cuba multiple times. Subtype B spread in Cuba through dissemination of strains that probably came from the USA, Canada and Europe. The time of the most recent common ancestor of Cuban subtype B was close to 1977close to (95% CI 1974close to -1982, and the evolutionary rate was 2.7 x 10 -3 nucleotide substitutions per site per year.CONCLUSIONS Our results suggest multiple introductions of HIV-1B into Cuba in the late 1970s, predominantly strains from North America and Europe. The results refl ect the importance of maintaining, reviewing and updating molecular epidemiology of HIV-1 in Cuba, due to its rapid evolution and possible implications for the National STI/HIV/AIDS Program of Cuba's Ministry of Public Health.