Dr. Andrew Papadopoulos

1. Using Underreporting Estimatesto Mobilize the Development ofTargeted, Proactive Food Safety Policy Dr. Andrew Papadopoulos Coordinator, Master of Public Health ProgramDepartment of Population MedicineUniversity of GuelphMay 29, 2014

2. Agenda • Introduction (Importance) • Methods (Statistical Approach) • Results (What we Found) • Discussion (So What) • Conclusion (What Have we Learned)

3. Introduction • Campylobacter and Salmonella infections are the most commonly reported foodborne infections in Ontario • These infections (laboratory confirmed) are reported to the Ontario Ministry of Health Long-Term Care (MOHLTC) through Ontario’s 36 boards of health

4. Introduction • Foodborne infections are underreported due to nonspecific symptoms, nonsevere symptoms among healthy populations, and lack of diagnostic testing among those that seek care • It is estimated between 11 and 13 million people in Canada each year experience some form of foodborne illness

5. Introduction • DALYs is a cost-utility measure used to classify diseases in order of their burden • Policy makers will use such measurements to identify healthcare priorities within their communities • Client ≠ Funder

6. Methods • Incidence rates for Ontario between 2006 and 2009, categorized by age and five-year increments and by gender were generated • These incidence rates were adjusted using Thomas et al. (2006) estimates of actual infection rates to account for underreporting

7. Methods • A Poisson regression was used to assess the predictor variables of interest (year, age, gender) had any impact on Salmonella or Campylobacter infection rates • The total number of infections were reduced to include only those caused by foodborne illness • Interactions were tested • The model was evaluated for over dispersion

8. Methods • Actual and estimated DALYs were calculated using a Microsoft Excel template from the World Health Organization for both Salmonella and Campylobacter for 2009

9. Results Incidence rate based on cases reported to the Ontario Ministry of Health and Long-Term Care of salmonellosis and campylobacteriosis attributed to foodborne illness in Ontario, 2009

10. Results SalmonellaInfections • The final model contained only the main effects • All two-way and three-interaction terms were not significant • The final model was assessed to determine if it fit a negative binomial distribution • The deviance was estimated to be 0.004 with a standard error of 0.0017 and was not significant • Data fit a Poisson distribution

11. Results SalmonellaInfections • All age categories were higher than the 0 to 4 age category (P<0.01) when all other variables in the model were held constant • All age categories had a relative risk less than 1 and therefore, having an age of 5 or older had a protective effect

12. Results CampylobacterInfections • The final model contained the main effects and the interaction term of age category and year • The two other two-way interaction terms and the three-interaction term were not significant • The final model was assessed to determine if it fit a negative binomial distribution • The deviance was estimated to be 0.064 with a standard error of 0.0024 and was not significant • Data fit a Poisson distribution

13. Results CampylobacterInfections • All age categories between 5 and 59 and older than 80 differed significantly (P<0.05) than the 0 to 4 age category when controlling for other variables in the model • These age categories had a less than expected rate of infection and therefore, belonging to one of these age categories had a protective effect

14. Results Salmonellosis – DALYs per 1000 population

15. Results Campylobacterosis – DALYs per 1000 population

16. Discussion • Incidence rates for Salmonella and Campylobacter infection between 2006 and 2009 were relatively consistent to those found across Canada and other developed nations • Incidence rates for the age category of 0 to 4 for both Salmonella and Campylobacter infection was the greatest • Campylobacter infection had elevated rates for the age groups between 20 and 29 and 60 and 69 • Slight variation as it is usually 20 to 29 age group only

17. Discussion • DALYs were modest for both Salmonella and Campylobacter infection • 1/10 of Clostridium difficile • 1/20 of influenza viruses, HPV and hepatitis B virus • 1/50 of HIV/AIDS • DALYs remained modest even when adjusted for the underreporting estimates • This will not capture the attention of policy makers

18. Discussion • Adjusting infections rates by known actual estimates can begin to define the impact of these diseases and its true burden of illness • Using distribution data can help policy makers develop and implement effective retail food safety policy that targets segments of the population most affected • A modest policy intervention can have a large impact on the number of cases within a community

19. Conclusion • The impact of foodborne illness is not well understood • Surveillance and health protection activities continue but are not enhanced in scope • Developing and implementing targeted, proactive public health policy addressing community acquired foodborne illness can have a significant impact on a population’s health