title: [Molecular evaluation of norovírus in patients with acute gastroenteritis].
abstract: BACKGROUND
  Norovírus was recently identified as the main cause of outbreaks of acute gastroenteritis of non-bacterial origin worldwide and it is involved in episodes of foodborne origin. In this study, patients with symptoms of acute gastroenteritis were evaluated over a one-year period, in order to evaluate two methods for identifying norovírus (real-time and conventional polymerase chain reaction), along with its incidence, seasonality and predominant genotype.
  
  
  METHODS
  After RNA extraction, 50 samples were analyzed using conventional PCR and 365 were analyzed using real-time PCR. All the samples that presented positive results using both methods or discordant results were sequenced. In all, 13 samples were sequenced.
  
  
  RESULTS
  Out of the 50 samples tested using both methods, seven presented a positive result from the conventional method and 15 from real-time PCR. Out of the total of 365 samples tested using real-time PCR, 48 were positive. All of the sequenced samples were shown to present norovírus of genogroup II. Regarding the distribution of norovírus-positive sample incidence over the course of the year, higher frequency of positive cases was observed during the southern hemisphere spring, reaching 29.7% in November.
  
  
  CONCLUSIONS
  We observed that real-time PCR was more sensitive for identifying norovírus. The incidence of norovírus was 13.2% and genogroup II predominated among the population evaluated, with the greatest infection rate in the southern hemisphere spring.
authors.affiliation: Setor de Biologia Molecular, Laboratório Weinmann, Porto Alegre, RS, Brazil. sofa_g77@hotmail.com
authors.forename: Sofia
authors.initials: S
authors.lastname: Georgiadis
authors.forename: Diogo André
authors.initials: DA
authors.lastname: Pilger
authors.forename: Fabiana
authors.initials: F
authors.lastname: Pereira
authors.forename: Vlademir Vicente
authors.initials: VV
authors.lastname: Cantarelli
mesh_terms: D000208:Acute Disease; D001938:Brazil / Q000453:epidemiology; D005243:Feces / Q000821:virology*; D005759:Gastroenteritis / Q000821:virology*; D005838:Genotype; D006801:Humans; D015994:Incidence; D029322:Norovirus / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods; D012367:RNA, Viral / Q000032:analysis*; D012621:Seasons
chemical_list: D012367:RNA, Viral