Outbreak of Norovirus GII.P17-GII.17 in the Canadian Province of Nova Scotia.

Background. Norovirus is the leading cause of viral gastroenteritis, with GII.4 being the most common circulating genotype. Recently, outbreaks in China revealed that norovirus GII.17 GII.P17 had become predominant. Objective. This study aimed to characterize the distribution of norovirus genotypes circulating in Nova Scotia. Methods. Stool specimens were collected from gastrointestinal outbreaks in Nova Scotia between Jan 2014 and June 2015 and subjected to real-time RT-PCR. Norovirus-positive specimens were referred to the National Microbiology Laboratory for sequence-based genotyping. Results. The first norovirus GII.P17-GII.17 outbreak in Canada was identified, but no widespread activity was observed in Nova Scotia. Discussion. It is unknown whether GII.P17-GII.17 is more widespread in Canada since contributions to Canadian surveillance are too sparse to effectively monitor the epidemiology of emerging norovirus genotypes. Conclusions. Presence of norovirus GII.17:P17 in Canada highlights the need for more systematic surveillance to ensure that molecular targets used for laboratory detection are effective and help understand norovirus evolution, epidemiology, and pathogenesis.

Molecular characterization of rotavirus isolates from select Canadian pediatric hospitals.

BACKGROUND: We report the first multi-site rotavirus genotype analysis in Canada. Prior to this study, there was a dearth of rotavirus G and P genotyping data in Canada. Publically funded universal rotavirus vaccination in Canada started in 2011 and has been introduced by four provinces to date. Uptake of rotavirus vaccines in Canada prior to 2012 has been very limited. The aim of this study was to describe the genotypes of rotavirus strains circulating in Canada prior to widespread implementation of rotavirus vaccine by genotyping samples collected from selected paediatric hospitals. Secondly we identified rotavirus strains that differed genetically from those included in the vaccines and which could affect vaccine effectiveness. METHODS: Stool specimens were collected by opportunity sampling of children with gastroenteritis who presented to emergency departments. Samples were genotyped for G (VP7) genotypes and P (VP4) genotypes by hemi-nested multiplex PCR methods. Phylogenetic analysis was carried out on Canadian G9 strains to investigate their relationship to G9 strains that have circulated in other regions of the world. RESULTS: 348 samples were collected, of which 259 samples were rotavirus positive and genotyped. There were 34 rotavirus antigen immunoassay negative samples genotyped using PCR-based methods. Over the four rotavirus seasons, 174 samples were G1P[8], 45 were G3P[8], 22 were G2P[4], 13 were G9P[8], 3 were G4P[8] and 2 were G9P[4]. Sequence analysis showed that all Canadian G9 isolates are within lineage III. CONCLUSIONS: Although a limited number of samples were obtained from a median of 4 centres during the 4 years of the study, it appears that currently approved rotavirus vaccines are well matched to the rotavirus genotypes identified at these hospitals. Further surveillance to monitor the emergence of rotavirus genotypes in Canada is warranted.

The hidden costs and characteristics of childhood rotavirus emergency visits in Canada.

BACKGROUND: Administrative databases are often used to determine burden of rotavirus disease in emergency departments (EDs). Our objective was to describe rotavirus ED visits to include healthcare utilization pre- and postvisit to estimate true societal costs. METHODS: During rotavirus seasons in 2007, 2008, and 2009, a convenience sample of children <3 years of age with vomiting and/or diarrhea and rotavirus in stool samples at ED visits was identified at 5 pediatric hospitals in Canada. Interviews took place within 24 hours and 2 weeks after diagnosis, and ED charts were reviewed. Using unit costs for all resources, healthcare and societal costs were determined in Canadian dollars. RESULTS: A total of 199 children (mean age, 16 months; range, 1-35 months) had rotavirus and had a completed initial questionnaire on record. Prior healthcare provider visits had occurred in 104 (52.3%) before and 50/172 (29.1%) children 2 weeks after the ED visit. The mean healthcare cost of the ED visit alone was $218.10 (95% confidence interval [CI]: $198, $238), and the mean societal cost was $261.40 (95% CI: $240, $283). Including both total healthcare and parental costs, this increased to a mean total societal cost of $674.80 (95% CI: $578, $771) per episode of rotavirus infection. CONCLUSIONS: Both the pre- and postvisit costs contribute substantially to the societal costs associated with an ED visit for rotavirus infection. In Canada, we estimate that the annual healthcare cost for children requiring a rotavirus ED visit ranges from $4.5 to $9.3 million, but when parental costs are included, the total societal cost ranges from $8.9 to $18.4 million.