title: Pet dogs--a transmission route for human noroviruses?
abstract: BACKGROUND
  Human noroviruses (HuNoVs) are one of the leading causes of diarrhoeal diseases worldwide in all age groups. Virus transmission can occur via the faecal-oral route from person to person or via contaminated food, water, or surfaces. The most common NoV strains circulating among humans belong to genogroup GII. Thus far, to our knowledge, no HuNoVs have been detected in pets.
  
  
  OBJECTIVE
  We investigated whether pet dogs could serve as carriers for HuNoVs and thereby transmit the infection to humans.
  
  
  METHODS
  Ninety-two faecal samples of indoor pet dogs were obtained. The main criteria for sample collection were that the dog or humans in the household had suffered from diarrhoea or vomiting. All samples were screened for HuNoV genogroups GI, GII, and GIV by real-time one-step RT-PCR.
  
  
  RESULTS
  We detected HuNoV in four faecal samples from pet dogs that had been in direct contact with symptomatic persons. Three of the positive samples contained genotype GII.4 variant 2006b or 2008 and one GII.12. All NoV-positive dogs lived in households with small children and two dogs showed mild symptoms.
  
  
  CONCLUSIONS
  Our results suggest that HuNoVs can survive in the canine gastrointestinal tract. Whether these viruses can replicate in dogs remains unresolved, but an association of pet dogs playing a role in transmission of NoVs that infect humans is obvious.
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland. maija.summa@helsinki.fi
authors.forename: Maija
authors.initials: M
authors.lastname: Summa
authors.forename: Carl-Henrik
authors.initials: CH
authors.lastname: von Bonsdorff
authors.forename: Leena
authors.initials: L
authors.lastname: Maunula
mesh_terms: D000328:Adult; D000818:Animals; D017250:Caliciviridae Infections / Q000635:transmission* / Q000662:veterinary*; D002648:Child; D015331:Cohort Studies; D004283:Dog Diseases / Q000821:virology*; D004285:Dogs; D005243:Feces / Q000821:virology; D005260:Female; D006801:Humans; D008297:Male; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D057805:Pets / Q000821:virology*; D010802:Phylogeny; D011795:Surveys and Questionnaires; D015047:Zoonoses / Q000821:virology*