Genetic diversity of porcine Norovirus and Sapovirus: Canada, 2005-2007.

Noroviruses and sapoviruses are members of the family Caliciviridae and emerging enteric pathogens of humans and animals. Since their discovery and characterization in swine, relatively few strains have been described in detail. In order to investigate their genetic diversity, a total of 266 fecal samples collected in the province of Quebec, Canada, between 2005 and 2007 were screened for the presence of caliciviruses by RT-PCR using broadly reactive primers. Genetically heterogeneous caliciviruses were detected on the majority of farms. Typical noroviruses related to known swine genotypes were present on 20% of the farms. Sapoviruses were detected on 75% of the farms and were the most heterogeneous group. Further characterization of selected strains in their 3' end parts was carried out for their classification and unveiled possibly new clusters of sapoviruses. No human-like noroviruses or sapoviruses were detected in the present study.