title: Impact of an emergent norovirus variant in 2009 on norovirus outbreak activity in the United States.
abstract: In October 2009, a new genogroup II, type 4 (GII.4) norovirus variant was identified in the United States. We collected norovirus outbreak data from 30 states to assess whether this new strain was associated with increased acute gastroenteritis activity. No increase in norovirus outbreaks was observed during the 2009-2010 winter.
authors.affiliation: Epidemic Intelligence Service Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. cyen@cdc.gov
authors.forename: Catherine
authors.initials: C
authors.lastname: Yen
authors.forename: Mary E
authors.initials: ME
authors.lastname: Wikswo
authors.forename: Ben A
authors.initials: BA
authors.lastname: Lopman
authors.forename: Jan
authors.initials: J
authors.lastname: Vinje
authors.forename: Umesh D
authors.initials: UD
authors.lastname: Parashar
authors.forename: Aron J
authors.initials: AJ
authors.lastname: Hall
mesh_terms: D000208:Acute Disease; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology*; D003428:Cross Infection / Q000453:epidemiology / Q000821:virology; D004196:Disease Outbreaks; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology*; D005838:Genotype; D006801:Humans; D008134:Long-Term Care; D029322:Norovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D009735:Nursing Homes; D011159:Population Surveillance; D012621:Seasons; D014481:United States / Q000453:epidemiology