Novel Norovirus in Dogs | CDC EID

EID Journal Home > Volume 16, Number 6–June 2010

Volume 16, Number 6–June 2010
Dispatch
Novel Norovirus in Dogs with Diarrhea
João Rodrigo Mesquita, Leslie Barclay, Maria São José Nascimento, and Jan Vinjé
Author affiliations: University of Porto, Porto, Portugal (J.R. Mesquita, M.S.J. Nascimento); Polytechnic Institute of Viseu, Viseu, Portugal (J. R. Mesquita); and Centers for Disease Control and Prevention, Atlanta, Georgia, USA (L. Barclay, J. Vinjé)

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Abstract
To identify the prevalence and genetic variability of noroviruses in dogs, we tested fecal samples by using reverse transcription–PCR. We found canine norovirus in 40% and 9% of dogs with and without diarrhea, respectively. The virus was genetically unrelated to other noroviruses and constitutes a tentative new genogroup.
Human noroviruses (NoVs) are the most frequent cause of epidemic and sporadic acute gastroenteritis worldwide among humans of all ages (1,2). The virus is transmitted through ingestion of contaminated food or water or from person to person through the fecal–oral route. The close genetic relatedness of swine NoV with human NoVs of genogroup (G) II suggests the potential for transfer from animals to humans (3–5). In addition, recent findings of viruses genetically related to human NoVs, as well as to animal NoV sequences in pigs and calves, have raised concerns about the possible emergence of recombinant viruses (4).

NoVs are genetically heterogeneous viruses that belong to the family Caliciviridae. The viral capsid encloses a single-stranded, positive-sense RNA genome of 7.3–7.7 kb that is organized in 3 open reading frames (ORFs), of which ORF1 encodes a polyprotein that is proteolytically cleaved into 6 nonstructural proteins, including RNA-dependent RNA polymerase (RdRp), helicase, and protease (1). ORF2 and ORF3 encode major (viral protein [VP] 1) and minor (VP2) capsid proteins. The GLPSG and YGDD motifs of the RdRp protein are conserved among all members of the family Caliciviridae (6). The genus Norovirus currently comprises 5 genogroups, designated GI–GV, which can be grouped into at least 32 genetic clusters (2,7). Only viruses from GI, GII, and GIV have been associated with human disease. Recently, the finding of a novel GIV norovirus in a young dog (5) indicated that pets can be infected with NoVs. To identify the prevalence and genetic variability of NoVs in dogs, we tested fecal specimens from dogs with and without diarrhea.

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Novel Norovirus in Dogs | CDC EID