title: Molecular epidemiological studies show that hepatitis A virus is endemic among active homosexual men in Europe.
abstract: Large outbreaks of hepatitis A have occurred in Denmark, Germany, the Netherlands, Norway, Spain, Sweden, and the United Kingdom during the period 1997-2005 affecting homosexual men. A collaborative study was undertaken between these countries to determine if the strains involved in these hepatitis A outbreaks were related genetically. The N-terminal region of VP1 and the VP1/P2A region of the strains were sequenced and compared. The majority of the strains found among homosexual men from the different European countries formed a closely related cluster, named MSM1, belonging to genotype IA. Different HAV strains circulated among other risk groups in these countries during the same period, indicating that specific strains were circulating among homosexual men exclusively. Similar strains found among homosexual men from 1997 to 2005 indicate that these HAV strains have been circulating among homosexual men for a long time. The homosexual communities are probably too small within the individual countries to maintain HAV in their population over time, whereas the homosexual communities across Europe are probably sufficiently large to sustain continued circulation of homologous HAV strains for years resulting in an endemic situation among homosexual men.
authors.affiliation: Division of Infectious Disease Control, Norwegian Institute of Public Health, Oslo, Norway. kasj@fhi.no
authors.forename: Kathrine
authors.initials: K
authors.lastname: Stene-Johansen
authors.forename: Grace
authors.initials: G
authors.lastname: Tjon
authors.forename: Eckart
authors.initials: E
authors.lastname: Schreier
authors.forename: Viviane
authors.initials: V
authors.lastname: Bremer
authors.forename: Sylvia
authors.initials: S
authors.lastname: Bruisten
authors.forename: Siew-Lin
authors.initials: SL
authors.lastname: Ngui
authors.forename: Mike
authors.initials: M
authors.lastname: King
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Pinto
authors.forename: Lluis
authors.initials: L
authors.lastname: Aragonès
authors.forename: Anne
authors.initials: A
authors.lastname: Mazick
authors.forename: Sylvie
authors.initials: S
authors.lastname: Corbet
authors.forename: Lena
authors.initials: L
authors.lastname: Sundqvist
authors.forename: Hans
authors.initials: H
authors.lastname: Blystad
authors.forename: Helene
authors.initials: H
authors.lastname: Norder
authors.forename: Kjell
authors.initials: K
authors.lastname: Skaug
mesh_terms: D004196:Disease Outbreaks; D005060:Europe / Q000453:epidemiology; D005814:Genes, Viral / Q000235:genetics; D006506:Hepatitis A / Q000453:epidemiology*; D030041:Hepatitis A virus / Q000145:classification / Q000235:genetics*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D010802:Phylogeny; D013045:Species Specificity; D015678:Viral Structural Proteins / Q000235:genetics
chemical_list: C096539:VP1 protein, hepatitis A virus; D015678:Viral Structural Proteins