Evolution of illness severity in hospital admissions due to COVID-19, Québec, Canada, January to April 2022.

Background: The coronavirus disease 2019 (COVID-19) severity is influenced by multiple factors, such as age, underlying medical conditions, individual immunity, infecting variant, and clinical practice. The highly transmissible Omicron variants resulted in decreased COVID-19 screening capacity, which limited disease severity surveillance.

Objective: To report on the temporal evolution of disease severity among patients admitted to Québec hospitals due to COVID-19 between January 2, 2022, and April 23, 2022, which corresponded to the peak period of hospitalizations due to Omicron.

Acute severe hepatitis of unknown origin in children in Canada.

Background: In spring 2022, a series of reports from the United Kingdom and the United States identified an increase in the incidence of acute severe hepatitis in children. The Public Health Agency of Canada (PHAC) collaborated with provincial/territorial health partners to investigate in Canada. Clinical hepatitis, or inflammation of the liver, is not reportable in Canada, so to determine if an increase was occurring above historical levels, the baseline incidence in Canada was estimated.

Impact of chronic comorbidities on hospitalization, intensive care unit admission and death among adult vaccinated and unvaccinated COVID-19 confirmed cases during the Omicron wave.

Background: Comorbidities are important risk factors of severe COVID-19 complications. Their impact during the Omicron wave among vaccinated and unvaccinated COVID-19 cases is not well documented.

Purpose: The objective of this study was to estimate the association between the number of comorbidities and the risk of hospitalization, intensive care unit (ICU) admission, and death among vaccinated and unvaccinated confirmed adult COVID-19 cases during the Omicron wave.