title: A Farm to Fork Risk Assessment for the Use of Wastewater in Agriculture in Accra, Ghana.
abstract: The need to minimise consumer risk, especially for food that can be consumed uncooked, is a continuing public health concern, particularly in places where safe sanitation and hygienic practices are absent. The use of wastewater in agriculture has been associated with disease risks, though its relative significance in disease transmission remains unclear. This study aimed at identifying key risk factors for produce contamination at different entry points of the food chain. Over 500 produce and ready-to-eat salad samples were collected from fields, markets, and kitchens during the dry and wet seasons in Accra, Ghana, and over 300 soil and irrigation water samples were collected. All samples were analysed for E. coli, human adenovirus and norovirus using standard microbiological procedures, and real time RT-PCR. Finally, critical exposures associated with microbial quality of produce were assessed through observations and interviews. The study found that over 80% of produce samples were contaminated with E. coli, with median concentrations ranging from 0.64 to 3.84 Log E. coli/g produce. Prepared salad from street food vendors was found to be the most contaminated (4.23 Log E. coli/g), and that consumption of salad exceeded acceptable health limits. Key risk factors identified for produce contamination were irrigation water and soil at the farm level. Storage duration and temperature of produce had a significant influence on the quality of produce sold at markets, while observations revealed that the washed water used to rinse produce before sale was dirty. The source of produce and operating with a hygiene permit were found to influence salad microbial quality at kitchens. This study argues for a need to manage produce risk factors at all domains along the food chain, though it would be more effective to prioritise at markets and kitchens due to cost, ease of implementation and public health significance.
authors.affiliation: Environmental Health Group, Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel street, WC1E 7HT, London, United Kingdom.
authors.forename: Prince
authors.initials: P
authors.lastname: Antwi-Agyei
authors.affiliation: Environmental Health Group, Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel street, WC1E 7HT, London, United Kingdom.
authors.forename: Sandy
authors.initials: S
authors.lastname: Cairncross
authors.affiliation: Department of Epidemiology and Public Health, University College of London, 1-19 Torrington Place, London, United Kingdom.
authors.forename: Anne
authors.initials: A
authors.lastname: Peasey
authors.affiliation: London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom.
authors.forename: Vivien
authors.initials: V
authors.lastname: Price
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel street, London, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Bruce
authors.affiliation: Center for Global Safe Water, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Kelly
authors.initials: K
authors.lastname: Baker
authors.affiliation: Center for Global Safe Water, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Christine
authors.initials: C
authors.lastname: Moe
authors.affiliation: Water Research Institute (WRI), Council for Scientific and Industrial Research (CSIR), Accra, Ghana.
authors.forename: Joseph
authors.initials: J
authors.lastname: Ampofo
authors.affiliation: Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana - Legon, Accra, Ghana.
authors.forename: George
authors.initials: G
authors.lastname: Armah
authors.affiliation: Environmental Health Group, Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel street, WC1E 7HT, London, United Kingdom.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Ensink
mesh_terms: D000383:Agriculture / Q000191:economics*; D004926:Escherichia coli / Q000502:physiology; D005506:Food Contamination; D058870:Food, Organic / Q000382:microbiology; D005869:Ghana; D006801:Humans; D007239:Infections / Q000191:economics / Q000382:microbiology; D018570:Risk Assessment; D012307:Risk Factors; D012988:Soil Microbiology; D062065:Wastewater / Q000191:economics / Q000382:microbiology*
chemical_list: D062065:Wastewater