Estimating public health risks of infectious disease events: A Canadian approach to rapid risk assessment.

Background: The COVID-19 pandemic highlighted the need for timely, evidence-based rapid risk assessments (RRA) of infectious disease events to inform public health action during rapidly evolving situations with high uncertainty. In 2022, the Public Health Agency of Canada established a coordinated approach to public health risk assessment, including a methodology for qualitative RRA of infectious disease threats.

Objective: To describe the RRA methodology and illustrate its use with examples from different infectious hazards of public health concern.

African swine fever risk and plant-based feed ingredients: Canada's approach to risk management of imported feed products.

As a result of unprecedented spread of African swine fever (ASF) since 2018, Canada has taken additional steps to prevent introduction of the virus. While the role of plant-based feed in the transmission of ASF is not completely understood, it was identified that no mitigation measures were in place to address this uncertain risk. A risk analysis process was conducted with collaboration between government and industry, including an assessment of the costs and benefits of various risk mitigation options.

Avian influenza virus H13 circulating in ring-billed gulls (Larus delawarensis) in southern Ontario, Canada.

Avian influenza virus (AIV) was studied in ring-billed gulls (Larus delawarensis) in one breeding colony on Lake Erie in 2000, and two on Lake Ontario in both 2000 and 2004. Antibodies to H13 AIV were detected in 92% of adults in 2000 and 82% in 2004. Antibody prevalence in 3-wk-old chicks was 5%-30% (overall 15%) in 2000 and 21% and 76% (overall 48%) in 2004.

Rapid antigen-capture assay to detect West Nile virus in dead corvids.

The utility of the VecTest antigen-capture assay to detect West Nile virus (WNV) in field-collected dead corvids was evaluated in Manitoba and Ontario, Canada, in 2001 and 2002. Swabs were taken from the oropharynx, cloaca, or both of 109 American Crows, 31 Blue Jays, 6 Common Ravens, and 4 Black-billed Magpies from Manitoba, and 255 American Crows and 28 Blue Jays from Ontario. The sensitivity and specificity of the antigen-capture assay were greatest for samples from American Crows; oropharyngeal swabs were more sensitive than cloacal swabs, and interlaboratory variation in the results was minimal.