Drivers of uncertainty in estimates of foodborne gastroenteritis incidence

Background: Estimates of the incidence of foodborne illness are increasingly used at national and international levels to quantify the burden of disease and advocate for improvements in food safety. The calculation of such estimates involves multiple datasets and several disease multipliers, applied to dozens of pathogens. Unsurprisingly, this process often produces wide interval estimates.

infinity.dogmaMaterials and Methods: Using a model of foodborne gastroenteritis in Australia, we calculate the contribution of both data and multipliers to the width of the interval. We then compare pathogen-specific estimates of the proportion of gastroenteritis that is foodborne from national-level studies conducted in Canada, Greece, France, the Netherlands, New Zealand, the United Kingdom, and the United States.

Results: Overall, we estimate that 74% (range 63–92%) of the interval width for foodborne gastroenteritis in Australia is a result of uncertainty in the proportion of gastroenteritis that is due to contaminated food. Across national studies, we find considerable variability in point estimates and the width of interval estimates for the foodborne proportion for relatively common pathogens such as Salmonella spp., Campylobacter spp., and norovirus.

Conclusions: While some uncertainty in estimates of gastroenteritis incidence is inevitable, an understanding of the drivers of this uncertainty can help to focus further research. In particular, this work highlights the value of studies quantifying the routes of transmission for common pathogens.

Foodborne Pathogens and Disease. -Not available-, ahead of print. doi:10.1089/fpd.2014.1816.

Glass Kathryn, Ford Laura, and Kirk Martyn D.