Estimated hospitalizations attributed to norovirus and rotavirus infection in Canada, 2006-2010

Abstract

Enteric viruses including norovirus and rotavirus are leading causes of gastroenteritis in Canada. However, only a small number of clinical cases are actually tested for these pathogens leading to systematic underestimation of attributed hospitalizations in administrative databases. The objective of this analysis was to estimate the number of hospitalizations due to norovirus and rotavirus in Canada. Hospitalization records for acute gastroenteritis-associated discharges at all acute-care hospitals in Canada between 2006 and 2011 were analysed. Cause-unspecified gastroenteritis hospitalizations were modelled using age-specific negative binomial models with cause-specified gastroenteritis admissions as predictors. The coefficients from the models were used to estimate the number of norovirus and rotavirus admissions. The total annual hospitalizations for rotavirus were estimated to be between 4500 and 10 000. Total annual hospitalizations for norovirus were estimated to be between 4000 and 11 000. The mean total annual cost associated with these hospitalizations was estimated to be at least $16 million for rotavirus and $21 million for norovirus (all figures in Canadian dollars). This study is the first comprehensive analysis of norovirus and rotavirus hospitalizations in Canada. These estimates provide a more complete assessment of the burden and economic costs of these pathogens to the Canadian healthcare system.

Keywords: Norwalk agent and related viruses; rotavirus.

Fig. 1.

Seasonal pattern of cause-unspecified gastroenteritis hospitalizations, month and year of admission, by age group, 2006–2011, Canadian Institutes of Health Information – Hospital Morbidity Database.

Fig. 2.

Seasonal distribution of laboratory-confirmed norovirus infections reported to the National Enteric Surveillance Program (NESP) and estimated norovirus hospitalizations by month and year of admission, 2006–2011.

Fig. 3.

Seasonal distribution of laboratory-confirmed rotavirus infections reported to the National Enteric Surveillance Program (NESP) and estimated rotavirus hospitalizations by month and year of admission, 2006–2011.