title: Epidemiologic and molecular trends of "Norwalk-like viruses" associated with outbreaks of gastroenteritis in the United States.
abstract: Between July 1997 and June 2000, fecal specimens from 284 outbreaks of nonbacterial gastroenteritis were submitted to the Centers for Disease Control and Prevention for testing for "Norwalk-like viruses" (NLVs). Specimens were examined by reverse-transcription polymerase chain reaction and direct electron microscopy for the presence of NLVs. Adequate descriptive data were available from 233 of the outbreaks, and, of these, 217 (93%) were positive for NLVs. Restaurants and events with catered food were the most common settings, and contaminated food was the most common mode of transmission. Genogroup II (GII) strains were the predominant type (73%), with genogroup I strains causing 26% of all NLV-positive outbreaks. Certain GII clusters (GII/1,4,j) were more commonly associated with outbreaks in nursing home settings than with outbreaks in other settings. Strain diversity was great: one potential new sequence cluster was implicated in multiple outbreaks, and strains belonging to a tentative new genogroup were identified.
authors.affiliation: Viral Gastroenteritis Section, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Fankhauser
authors.forename: Stephan S
authors.initials: SS
authors.lastname: Monroe
authors.forename: Jacqueline S
authors.initials: JS
authors.lastname: Noel
authors.forename: Charles D
authors.initials: CD
authors.lastname: Humphrey
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Bresee
authors.forename: Umesh D
authors.initials: UD
authors.lastname: Parashar
authors.forename: Tamie
authors.initials: T
authors.lastname: Ando
authors.forename: Roger I
authors.initials: RI
authors.lastname: Glass
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D002648:Child; D002675:Child, Preschool; D019992:Databases as Topic; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005260:Female; D005516:Food Microbiology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D029322:Norovirus / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000032:analysis; D014481:United States / Q000453:epidemiology
chemical_list: D012367:RNA, Viral