How agricultural practices affect the risk of human contamination by infectious pathogens: the need for a “One Health” perspective

We conducted a comprehensive literature review with a global geographic scope, of interactions between agricultural crop production practices (excluding crop protection practices) and biological human health hazards. The majority of relevant references dealt with bacterial contaminations and infections, largely due to the important public health issue of antibiotic resistance. Indicator coliforms were particularly significant (only a minority mentioned harmful Escherichia coli strains), followed by species belonging to Salmonella, Campylobacter, Clostridia, Pseudomonas, and Listeria genera. Protozoan Cryptosporidium spp. and Giardia spp., and helminthic Ascaris spp. and Trichuris spp. dominated the references to parasites. Enteric viruses largely dominated the references to viruses (particularly noroviruses and rotaviruses). Very few references mentioned human fungal pathogens. Fresh vegetables were the most commonly mentioned crops, particularly leafy greens and those eaten raw, due to the use of wastewater for irrigation, and fertilization with livestock manure and human excreta/sewage sludge, potentially unsafe practices. While earlier literature reviews have shown that crop protection practices are central to the One Health concept, this review shows that other agricultural practices can also contribute to human and environmental health via different pathways, including better soil health, water quality, better food safety, and human nutrition. Our review underlines that besides tradeoffs, synergies should be sought, between, on the one hand, saving/preserving freshwater and organic waste recycling (affecting environmental health and some aspects of human health), and health hazards associated with the use of potentially contaminated waste on the other (affecting other aspects of human health), from both agroecological and One Health perspectives.