title: Epidemiological characteristics of norovirus associated with sporadic gastroenteritis among children from the 2006/2007 to 2011/2012 season in Nara Prefecture, Japan.
abstract: The present study aimed to describe the epidemiological characteristics of norovirus (NoV) associated with sporadic gastroenteritis in regional populations of Nara Prefecture, Japan, from the 2006/2007 to 2011/2012 epidemic season. Fecal specimens of sporadic gastroenteritis collected between September 2006 and August 2012 in Nara Prefecture were examined for the presence of NoV by reverse transcription-polymerase chain reaction. The NoV genotype was determined by nucleotide sequence analysis. In total, 274 NoVs associated with sporadic gastroenteritis were identified. We detected 10 different NoV genotypes: GI/3, GI/4, GI/8, GII/2, GII/3, GII/4, GII/6, GII/7, GII/12, and GII/13. A high NoV detection rate of 35.9% was identified in 1-year-old children. Among the 274 NoV isolates, 142 were obtained from males and 131 were obtained from females (the source of one was unknown). The most prevalent genotype was GII/4, accounting for 117 of the 192 different NoVs identified by sequencing. More epidemiological data will be required to determine the epidemiological characteristics of NoVs in other areas of Japan.
authors.affiliation: Virology and Epidemiology Division, Nara Prefecture Institute of Health, Sakurai City, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Yoneda
authors.forename: Akiko
authors.initials: A
authors.lastname: Okayama
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Kitahori
mesh_terms: D000293:Adolescent; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D012367:RNA, Viral