Hospital burden of influenza, respiratory syncytial virus, and other respiratory viruses in Canada, seasons 2010/2011 to 2018/2019.

Abstract

Objectives: The objective of this study was to develop a model to estimate the hospitalization burden attributable to influenza, respiratory syncytial virus (RSV), enterovirus (EV), human metapneumovirus (HMPV), human parainfluenza virus (HPIV), and other respiratory viruses (OV) in Canada.

Methods: A Poisson regression model was developed using respiratory hospitalization administrative data for the seasons 2010/2011 to 2018/2019.

Results: The estimated average seasonal number of respiratory hospitalizations attributable to influenza was 15,000 in Canada (rate 43.4 hospitalizations per 100,000 population [95%CI 40.9, 46.0]), and 13,000 (rate 36.3 hospitalizations per 100,000 population [95%CI 29.2, 43.4]) for RSV. The estimated average seasonal numbers of hospitalizations attributable to EV, HMPV, HPIV, and OV were 6000 (rate 16.2 hospitalizations per 100,000 population [95%CI 10.7, 21.8]), 4000 (rate 12.4 hospitalizations per 100,000 population [95%CI 7.1, 17.6]), 2000 (rate 5.9 hospitalizations per 100,000 population [95%CI 2.0, 9.8]), and 3000 (rate 8.9 hospitalizations per 100,000 population [95%CI 0.04, 17.7]), respectively.

Conclusion: This study provided updated and new Canadian estimates for hospitalizations attributable to influenza, RSV, EV, HMPV, and HPIV for 2010/2011 to 2018/2019 surveillance seasons. These estimates are important given the emergence of SARS-CoV-2 and the ongoing circulation of seasonal respiratory viruses. Routine burden estimation is pivotal in supporting the implementation and evaluation of public health programs focused at mitigating the impacts of respiratory viruses. Although multiple external factors are at play, this study indicates that influenza and RSV attributable hospitalizations were persisting and generally increasing in Canada in recent years preceding the COVID-19 pandemic.