title: Characterization of a highly evolved vaccine-derived poliovirus type 3 isolated from sewage in Estonia.
abstract: Two types of vaccine-derived polioviruses have been recently designated to emphasize the different origins of the evolved viruses: circulating vaccine-derived polioviruses (cVDPV) associated with outbreaks of paralytic disease and strains isolated from chronically infected immunodeficient individuals (iVDPV). We describe here a type 3 VDPV (PV3/EST/02/E252; later E252) isolated from sewage collected in Tallinn, Estonia, in October 2002. Due to aberrant properties in subtyping, the virus was subjected to detailed characterization. Partial genomic sequencing suggested that the closest relative was the oral vaccine strain PV3/Sabin, but the two virus strains shared only 86.7% of the 900 nucleotides (nt) coding for the capsid protein VP1. Phylogenetic analysis of the nearly complete genome [nt 19 to poly(A)] revealed multiple nucleotide substitutions throughout the genome and a possible Sabin 3/Sabin 1-recombination junction site in the 2C coding region. A calculation based on the estimated mutation frequency of the P1 region of polioviruses suggested that the E252 virus might have replicated in one or more individuals for approximately 10 years. No persons chronically excreting poliovirus are known in Estonia. Amino acid substitutions were seen in all known antigenic sites, which was consistent with the observed aberrant antigenic properties of the virus demonstrated by both monoclonal antibodies and human sera from vaccinated children. In spite of the apparent transmission potential, no evidence was obtained for circulation of the virus in the Estonian population.
authors.affiliation: Department of Microbiology, Enterovirus Laboratory, National Public Health Institute (KTL), 00300 Helsinki, Finland. soile.blomqvist@ktl.fi
authors.forename: Soile
authors.initials: S
authors.lastname: Blomqvist
authors.forename: Carita
authors.initials: C
authors.lastname: Savolainen
authors.forename: Pia
authors.initials: P
authors.lastname: Laine
authors.forename: Päivi
authors.initials: P
authors.lastname: Hirttiö
authors.forename: Elisa
authors.initials: E
authors.lastname: Lamminsalo
authors.forename: Eija
authors.initials: E
authors.lastname: Penttilä
authors.forename: Silver
authors.initials: S
authors.lastname: Jöks
authors.forename: Merja
authors.initials: M
authors.lastname: Roivainen
authors.forename: Tapani
authors.initials: T
authors.lastname: Hovi
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004957:Estonia; D019143:Evolution, Molecular; D016679:Genome, Viral; D006801:Humans; D007223:Infant; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D017955:Poliovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D011055:Poliovirus Vaccine, Oral / Q000276:immunology; D017422:Sequence Analysis, DNA; D012703:Serotyping; D012722:Sewage / Q000821:virology*; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D011055:Poliovirus Vaccine, Oral; D012722:Sewage