Changing epidemiology of Salmonella outbreaks associated with cucumbers and other fruits and vegetables

Abstract

Background: Salmonella is one of the leading causes of foodborne outbreaks globally, with chicken and eggs the most common food vehicles associated. Fruit and vegetables have increasingly been reported as vehicles for salmonella. Aims: We aimed to determine the trends in salmonella outbreaks associated with cucumbers, as well as other fruit and vegetables from 2009-2017. Methods: Data from the published and grey literature were searched to investigate outbreaks of Salmonella globally caused by fruit and vegetables and specifically cucumbers. An open-source epidemic database, Epi-Watch, was also searched for salmonella outbreaks. Results: We identified and described 39 Salmonella outbreaks due to fruit and vegetables between 2009 and 2017 from Northern America, Europe, and Australia, including 6 multi-state and 1 state-based outbreaks due to cucumbers, the first being documented in 2013. The proportion of Salmonella outbreaks cause by fruit and vegetables has been increasing, as observed in both the United States of America (USA) and Australia. Conclusions: There has been a shift in the epidemiology of foodborne Salmonella outbreaks, with a higher number and proportion now associated with fruit and vegetables. This includes novel vehicles such as cucumbers, only reported as a vehicle for Salmonella since 2013. Emergence of less common serotypes has been observed in outbreaks from 2017-2019. Prevention at the production stage is important with limited options for consumers to reduce their risk of vegetable-associated Salmonella. Globalisation, changes in farming practices and importation of produce remains a challenge in monitoring and ensuring safety in the food supply chain.

Keywords

• cucumber, salmonella, foodborne diseases, vegetables, novel vehicles, emerging epidemics