title: Reconstruction of the epidemic history of hepatitis B virus genotype D in Albania.
abstract: Despite a recent decrease in the prevalence of HBsAg in the general population, Albania is still highly endemic for HBV infection. Genotype D is the most prevalent HBV strain in the Mediterranean area. We studied the prevalence and distribution of HBV genotypes and subgenotypes in a total of 73 HBsAg-positive patients living in Albania, and reconstructed the epidemiological history of the most prevalent HBV D subgenotype using a "phylodynamic" framework. A time-scaled genealogy of the Albanian patients' and reference P gene sequences with known sampling dates was reconstructed using an MCMC Bayesian approach that allows population growth to be estimated on the basis of coalescent theory. All of the Albanian subjects were infected with the HBV D genotype, and a percentage varying from 44.4% to 100% (depending on the ethnic or risk group) were infected with subgenotype D2, the most prevalent in the study population (72.4%). The other subgenotypes present in a minority of subjects were D1 (13.8%) and D3 (13.8%). The Bayesian skyline plot population dynamics analysis showed that genotype D2 entered the Albanian population in the late 1960s, and that the effective number of infections grew gradually until the second half of the 1980s and more rapidly until the mid-1990s, when it reached a plateau that still persists today. Our data suggest that political and socio-economic factors played an important role in determining the rapid spread of HBV infection in Albania.
authors.affiliation: Department of Clinical Sciences Luigi Sacco, Chair of Infectious Diseases, University of Milan, Milan, Italy. gianguglielmo.zehender@unimi.it
authors.forename: Gianguglielmo
authors.initials: G
authors.lastname: Zehender
authors.forename: Renata
authors.initials: R
authors.lastname: Shkjezi
authors.forename: Erika
authors.initials: E
authors.lastname: Ebranati
authors.forename: Elena
authors.initials: E
authors.lastname: Gabanelli
authors.forename: Zhani
authors.initials: Z
authors.lastname: Abazaj
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Tanzi
authors.forename: Dhimiter
authors.initials: D
authors.lastname: Kraja
authors.forename: Silva
authors.initials: S
authors.lastname: Bino
authors.forename: Massimo
authors.initials: M
authors.lastname: Ciccozzi
authors.forename: Massimo
authors.initials: M
authors.lastname: Galli
mesh_terms: D000293:Adolescent; D000328:Adult; D000415:Albania / Q000453:epidemiology; D004279:DNA, Viral; D019143:Evolution, Molecular; D005260:Female; D005787:Gene Frequency; D005828:Genetics, Population; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology*; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D015995:Prevalence; D012307:Risk Factors; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D004279:DNA, Viral