title: Molecular epidemiology of norovirus infections in Stockholm, Sweden, during the years 2000 to 2003: association of the GGIIb genetic cluster with infection in children.
abstract: The incidence of norovirus-associated gastroenteritis and the molecular epidemiology of norovirus strains were studied during three seasons (2000-2001, 2001-2002, and 2002-2003) among patients of all ages, mainly from the Stockholm region in Sweden. A total of 3,252 fecal samples were analyzed by reverse transcription-PCR. The incidences of norovirus infection among adults were 23, 26, and 30% during the three seasons studied and 18, 11, and 15% among children 0 to 15 years of age. During the first season, all norovirus strains detected by PCR were typed either by reverse line blot hybridization or nucleotide sequence analysis. During the two successive seasons, a total of 60 norovirus-positive strains from the beginning, peak, and end of the seasons were selected for nucleotide sequence analysis. We identified two dominant norovirus variants over the seasons: a new norovirus variant, recently described as the GGIIb genetic cluster, dominated among children during the first season, and during the following two seasons, a GGII-4 variant dominated. Our data suggest that norovirus infections are common, not only among adults, but also among children, and that some strains may predominantly affect children.
authors.affiliation: Department of Clinical Microbiology, Karolinska University Hospital, Solna, SE-171 76 Stockholm, Sweden. annika.tiveljung-lindell@karolinska.se
authors.forename: Annika Tiveljung
authors.initials: AT
authors.lastname: Lindell
authors.forename: Lena
authors.initials: L
authors.lastname: Grillner
authors.forename: Lennart
authors.initials: L
authors.lastname: Svensson
authors.forename: Benita Zweygberg
authors.initials: BZ
authors.lastname: Wirgart
mesh_terms: D000293:Adolescent; D001483:Base Sequence; D017250:Caliciviridae Infections / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005759:Gastroenteritis / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012621:Seasons; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors