Low prevalence of human pathogens on fresh produce on farms and in packing facilities

Authors: VAN PELT, AMELIA - Emory University; Quinones, Beatriz; LOFGREN, HANNAH - Emory University; BARTZ, FAITH - Emory University; NEWMAN, KIRA - Emory University; LEON, JUAN - Emory University

Submitted to: FRONTIERS IN PUBLIC HEALTH
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2018
Publication Date: 2/23/2018
Citation: Van Pelt, A., Quinones, B., Lofgren, H., Bartz, F., Newman, K., Leon, J. 2018. Low prevalence of human pathogens on fresh produce on farms and in packing facilities. FRONTIERS IN PUBLIC HEALTH. https://doi.org/10.3389/fpubh.2018.00040.
DOI: https://doi.org/10.3389/fpubh.2018.00040

Interpretive Summary: The World Health Organization reports a global burden of 600 million cases of foodborne illness and 420,000 foodborne-attributed deaths in 2010. The majority of foodborne illnesses result from viral pathogens, such as norovirus, succeeded by bacterial pathogens, such as Salmonella, and parasite pathogens, such as Cyclospora. In agreement with this worldwide trend, from 2004-2013 in the United States, 36% of cases of foodborne illnesses resulted from consumption of contaminated produce. Produce can become contaminated with human pathogens during harvesting (farms) and packaging (packing facilities). For example, investigations into an outbreak of Salmonella in the United States in 2008 identified jalapeño farms in Mexico as the source of contamination. Further, investigators of a norovirus outbreak in Denmark in 2010 concluded that lettuce from a producer in France caused the infection. In a third example, researchers traced the source of a multistate outbreak of Listeria monocytogenes in the United States in 2011 to contamination of cantaloupe in packing facilities in Colorado. Thus, produce may become contaminated in one region but affect consumers in another location. Although outbreak data provides information on common pathogens and produce types involved in foodborne illness of the consumer, it often does not identify or quantify the source of contamination in the natural setting at the farm or packing facility. This article aims to determine the prevalence of human pathogens, such as bacteria, parasites, and viruses, on fresh produce, including fruits, herbs, and vegetables, on farms and in packing facilities through a systematic analysis of peer-reviewed literature published before August 2017. The analysis will provide a quantification of the ranges of human pathogen contamination on produce on farms and in packing facilities.

Technical Abstract: Foodborne illness burdens individuals around the world. Consumption of produce contaminated with bacterial, parasite, and viral pathogens causes a significant proportion of cases of foodborne illness. Farms and packing facilities provide opportunities for contamination. This research aimed to determine the ranges of prevalence of human pathogens (bacteria, parasites, and viruses) on fresh produce (fruits, herbs, and vegetables) on farms and in packing facilities through a systematic review of 38 peer-reviewed articles. The median and range of the prevalence was calculated, and Kruskall-Wallis tests and logistic regression were performed to compare pooled samples. Results indicated a low median percentage of pathogens on fresh produce (0%). No significant differences between commodity types or sample location were observed. When pooling pathogen types, viruses (p-value=0.0171) and parasites (p-value=0.0329) exhibited higher prevalence than bacteria. These results serve as a reference to identify contamination to prevent future foodborne illness and suggest that contamination of produce with pathogens may occur during other stages in the process between processing and consumption.