Food Safety at Farmers' Markets: A Knowledge Synthesis of Published Research.

Farmers' markets are increasingly popular venues in North America for the sale of fresh produce and other foods. However, the nature of their operation can present possible food safety issues, challenges, and risks to consumers. A knowledge synthesis was conducted to identify, characterize, and summarize published research on the microbial food safety issues and implications associated with farmers' markets. A scoping review was conducted using the following steps: comprehensive search strategy, relevance screening of abstracts, and characterization of relevant articles. Two subsets of data were prioritized for more detailed systematic review (data extraction and risk-of-bias assessment) and meta-analysis: (i) studies comparing the microbial safety of foods from farmers' markets versus other sources and (ii) studies evaluating the use of food safety practices at farmers' markets. Overall, 83 relevant studies were identified. The majority of studies were published as journal articles (64%), used a cross-sectional design (81%), and were conducted in the United States (78%). Most studies (39%; n = 32) investigated stakeholder, mostly consumer (n = 22), attitudes toward food safety at farmers' markets. Limited but heterogeneous evidence indicated a higher prevalence of Campylobacter and Salmonella in chicken meat from farmers' markets versus other retail sources, but there was no difference in the microbial contamination of fresh produce. Studies evaluating the use of food safety practices at farmers' markets identified some gaps; for example, the average prevalence of vendor hand washing was 4% (95% confidence interval: 0 to 11%; I2 = 27%; n = 5 studies). Twelve foodborne outbreaks and case reports were identified, resulting in a total of 411 illnesses, 38 hospitalizations, and two deaths from 1994 to 2016. Only five intervention studies were identified. Key knowledge gaps and areas warranting future research, training, and education are highlighted and discussed.