Vayshali Patel ^1,2 Lauren E. Grant ^1* Hisba Shereefdeen ^1,2 Melissa MacKay ¹ Leslie Cheng ² Melissa Phypers ² Andrew Papadopoulos ¹ Jennifer E Mcwhirter ¹

• ¹ University of Guelph, Guelph, Canada
• ² Centre for Foodborne, Environmental and Zoonotic Infectious Diseases, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada

Introduction: Most Canadians social media platforms regularly, making it an effective tool for reaching broad audiences. The Public Health Agency of Canada (PHAC) uses social media to communicate with the public during multi-jurisdictional enteric illness outbreaks. However, the effectiveness of social media in enhancing public risk communication during these outbreaks remains unexplored. Addressing this gap may optimize its use to inform the public and prevent additional illness. This study analyzes engagement with and quality of PHAC’s social media content regarding multi-jurisdictional enteric illness outbreaks. Methods: Using a search of PHAC’s social media platforms, 482 posts during enteric illness outbreaks (2014-2022) were identified, including 198 posts from Facebook and 284 posts from X (formerly Twitter) in English and French. A codebook was developed using engagement metrics for gauging public interest, the Centers for Disease Control and Prevention’s (CDC) Modified Clear Communication Index (CCI) to assess clarity as a proxy for comprehension, the Health Belief Model (HBM) to evaluate potential to motivate behaviour change, and measures of consistency. Descriptive statistics were used to analyze post content. Results: The average engagement rates for PHAC social media accounts were <1%, below standard average engagement rates (1%-5%). While posts generally adhered to the CDC’s CCI criteria, clear language (45.7% on Facebook, 26.5% on X) and clear communication of risk (7.6% on Facebook, 0.0% on X) were scarce. HBM constructs were present in all posts, but certain constructs, such as barriers were used sparingly (1% on Facebook, 0% on X). Posts consistently communicated outbreak investigation details and prevention information. Discussion: Low engagement rates suggest a lack of public awareness or interest in the posts. Partial adherence to the CCI indicates room for improving clarity, a component for supporting public understanding. Although some HBM constructs were utilized, no posts incorporated all constructs, potentially hindering efforts to promote behaviour change. To enhance effective risk communication using social media during multi-jurisdictional enteric illness outbreaks in Canada, the CDC’s CCI should be used to improve message clarity, use of all HBM constructs, and message consistency across products and channels is recommended to improve overall message quality and content.