title: Norovirus gastroenteritis general outbreak associated with raw shellfish consumption in south Italy.
abstract: BACKGROUND
  Despite Noroviruses (NV, previously "Norwalk-like viruses") being a leading cause of acute gastroenteritis outbreaks, the impact of NV infection is at present unknown and little information is available about strains circulating in Italy. In April 2002 an outbreak of gastroenteritis occurred in the province of Bari (South-east Italy), involving several households.
  
  
  METHODS
  A retrospective cohort study was performed in order to assess risk factors associated with illness. All households where a case occurred were included in the study. Faecal specimens were collected from ill individuals. NV-specific RT-PCR was performed. Eleven samples of mussels were collected from fish-markets involved in the outbreak. A nested PCR was used for mussel samples.
  
  
  RESULTS
  One hundred and three cases, detected by means of active surveillance, met the case definition. Raw shellfish eating was the principal risk factor for the disease, as indicated by the analytic issues (Risk Ratio: 1.50; IC 95%: 1.18 - 1.89; p < 0.001). NVs were found by means of RT-PCR of all the stool specimens from the 24 patients tested. Eleven samples of shellfish from local markets were tested for the presence or NVs; six were positive by nested PCR and genotypes were related to that found in patients' stools.
  
  
  CONCLUSIONS
  This is the first community outbreak caused by NVs related to sea-food consumption described in Italy. The study confirms that the present standards for human faecal contamination do not seem to be a reliable indicator of viral contaminants in mussels.
authors.affiliation: Dipartimento di Scienze Mediche e del Lavoro, Section of Hygiene, University of Foggia, Italy. r.prato@unifg.it
authors.forename: Rosa
authors.initials: R
authors.lastname: Prato
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Lopalco
authors.forename: Maria
authors.initials: M
authors.lastname: Chironna
authors.forename: Giovanna
authors.initials: G
authors.lastname: Barbuti
authors.forename: Cinzia
authors.initials: C
authors.lastname: Germinario
authors.forename: Michele
authors.initials: M
authors.lastname: Quarto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D049872:Bivalvia / Q000821:virology*; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004279:DNA, Viral / Q000032:analysis / Q000737:chemistry; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005260:Female; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D017747:Seafood / Q000821:virology*; D016415:Sequence Alignment
chemical_list: D004279:DNA, Viral