title: Genetic Diversity of the Hepatitis B Virus Strains in Cuba: Absence of West-African Genotypes despite the Transatlantic Slave Trade.
abstract: Cuba is an HBsAg low-prevalence country with a high coverage of anti-hepatitis B vaccine. Its population is essentially the result of the population mix of Spanish descendants and former African slaves. Information about genetic characteristics of hepatitis B virus (HBV) strains circulating in the country is scarce. The HBV genotypes/subgenotypes, serotypes, mixed infections, and S gene mutations of 172 Cuban HBsAg and HBV-DNA positive patients were determined by direct sequencing and phylogenetic analysis. Phylogenetic analysis of HBV S gene sequences showed a predominance of genotype A (92.4%), subgenotype A2 (84.9%) and A1 (7.6%). Genotype D (7.0%) and subgenotype C1 (0.6%) were also detected but typical (sub)genotypes of contemporary West-Africa (E, A3) were conspicuously absent. All genotype A, D, and C strains exhibited sequence characteristics of the adw2, ayw2, and adrq serotypes, respectively. Thirty-three (19.1%) patients showed single, double, or multiple point mutations inside the Major Hydrophilic domain associated with vaccine escape; eighteen (10.5%) patients had mutations in the T-cell epitope (amino acids 28-51), and there were another 111 point mutations downstream of the S gene. One patient had an HBV A1/A2 mixed infection. This first genetic study of Cuban HBV viruses revealed only strains that were interspersed with strains from particularly Europe, America, and Asia. The absence of genotype E supports previous hypotheses about an only recent introduction of this genotype into the general population in Africa. The presence of well-known vaccine escape (3.5%) and viral resistance mutants (2.9%) warrants strain surveillance to guide vaccination and treatment strategies.
authors.affiliation: Pedro Kourí Institute of Tropical Medicine, Havana, Cuba.
authors.forename: Licel A
authors.initials: LA
authors.lastname: Rodríguez Lay
authors.affiliation: Centro de Investigaciones Médico-Quirúrgicas, CIMEQ, Havana, Cuba.
authors.forename: Marité B
authors.initials: MB
authors.lastname: Corredor
authors.affiliation: Pedro Kourí Institute of Tropical Medicine, Havana, Cuba.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Villalba
authors.affiliation: Pedro Kourí Institute of Tropical Medicine, Havana, Cuba.
authors.forename: Susel S
authors.initials: SS
authors.lastname: Frómeta
authors.affiliation: Pedro Kourí Institute of Tropical Medicine, Havana, Cuba.
authors.forename: Meilin S
authors.initials: MS
authors.lastname: Wong
authors.affiliation: Pedro Kourí Institute of Tropical Medicine, Havana, Cuba.
authors.forename: Lidunka
authors.initials: L
authors.lastname: Valdes
authors.affiliation: Centro de Investigaciones Médico-Quirúrgicas, CIMEQ, Havana, Cuba.
authors.forename: Marcia
authors.initials: M
authors.lastname: Samada
authors.affiliation: Laboratory of Immunology, Luxembourg Institute of Health, Esch-Sur- Alzette, Grand-Duchy of Luxembourg.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Sausy
authors.affiliation: Laboratory of Immunology, Luxembourg Institute of Health, Esch-Sur- Alzette, Grand-Duchy of Luxembourg.
authors.forename: Judith M
authors.initials: JM
authors.lastname: Hübschen
authors.affiliation: Laboratory of Immunology, Luxembourg Institute of Health, Esch-Sur- Alzette, Grand-Duchy of Luxembourg.
authors.forename: Claude P
authors.initials: CP
authors.lastname: Muller
mesh_terms: D003462:Cuba; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny