One of the largest reported campylobacteriosis outbreaks in Canada occurred in June 2007 in British Columbia, associated with a mountain bike race that took place in muddy conditions. A retrospective cohort study was conducted and environmental samples were collected and tested. There were 537 racers included in the study and 225 racers (42%) reported diarrhoeal illness after the race. C. jejuni clinical isolates (n=14) were found to be identical by multi-locus sequence typing. Although univariate analysis suggested water consumption and mud exposure as significant risk factors, multivariate analysis revealed that on direct ingestion mud was significantly associated with illness (OR 4·08, 95% CI 2·03-8·21). Contaminated mud was thus the most likely source of Campylobacter infection. We identified other unpublished reports of outbreaks associated with bike races in rainy or muddy conditions; these underscore the importance of educating racers and raising public awareness of the risks of mud ingestion.

Background: Influenza is a respiratory infection caused primarily by influenza A and B viruses. Vaccination is the most effective way to prevent influenza and its complications. The National Advisory Committee on Immunization (NACI) provides recommendations regarding seasonal influenza vaccines annually to the Public Health Agency of Canada (PHAC).

A campylobacteriosis outbreak investigation provides relevant examples of how two web-based technologies were used in an outbreak setting and potential reasons for their usefulness. A web forum aided in outbreak detection and provided contextual insights for hypothesis generation and questionnaire development. An online questionnaire achieved a high response rate and enabled rapid preliminary data analysis that allowed for a targeted environmental investigation. The usefulness of these tools may in part be attributed to the existence of an internet savvy, close-knit community. Given the right population, public health officials should consider web-based technologies, including web fora and online questionnaires as valuable tools in public health investigations.

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Background: There are many different influenza vaccines authorized for use in Canada and new evidence on influenza and vaccines is emerging all the time. The National Advisory Committee on Immunization (NACI) provides recommendations annually regarding seasonal influenza vaccines to the Public Health Agency of Canada (PHAC). Objective: To summarize the NACI recommendations regarding the use of seasonal influenza vaccines for the 2018-2019 influenza season in light of two NACI reviews conducted on 1) the risk of serious influenza-related complications in children and adults with neurologic and neurodevelopment conditions and 2) the efficacy/effectiveness of high-dose and adjuvanted inactivated influenza vaccines in persons 65 years of age and older. Methods: For both topics, NACI's Influenza Working Group developed a predefined search strategy to identify all eligible studies, assessed their quality, summarized and analyzed the findings, proposed recommendations and identified the Grade of evidence that supported them. In light of the evidence, the recommendations were then considered and approved by NACI. Results: NACI concludes there is fair evidence to recommend that children and adults with neurologic and neurodevelopment conditions are groups for whom influenza immunization is particularly recommended (Evidence Grade B recommendation). On choosing influenza vaccines for persons 65 years of age and older, at a programmatic level, NACI recommends that any of the four influenza vaccines available for use should be used. There is insufficient evidence to make a comparative recommendation on the use of these vaccines at a programmatic level (Grade I). At an individual level, NACI recommends that high-dose trivalent inactivated influenza vaccine (TIV) should be offered over standard-dose TIV to persons 65 years of age and older (Grade A). There is insufficient evidence to make comparative recommendations on the use of MF59-adjuvanted TIV and quadrivalent inactivated influenza vaccine over standard-dose TIV (Grade I). Conclusion: NACI continues to recommend annual influenza vaccination for all individuals aged six months and older, with particular focus on people at high risk of influenza-related complications or hospitalization, people capable of transmitting influenza to those at high risk, people who provide essential community services and people in direct contact during culling operations with poultry infected with avian influenza.