title: Risk of Illness with Salmonella due to Consumption of Raw Unwashed Vegetables Irrigated with Water from the Bogotá River.
abstract: The Bogotá River receives untreated wastewater from the city of Bogotá and many other towns. Downstream from Bogotá, water from the river is used for irrigation of crops. Concentrations of indicator organisms in the river are high, which is consistent with fecal contamination. To investigate the probability of illness due to exposure to enteric pathogens from the river, specifically Salmonella, we took water samples from the Bogotá River at six sampling locations in an area where untreated water from the river is used for irrigation of lettuce, broccoli, and cabbage. Salmonella concentrations were quantified by direct isolation and qPCR. Concentrations differed, depending on the quantification technique used, ranging between 107.7and 109.9number of copies of gene invA per L and 105.3and 108.4CFU/L, for qPCR and direct isolation, respectively. A quantitative microbial risk assessment model that estimates the daily risk of illness with Salmonella resulting from consuming raw unwashed vegetables irrigated with water from the Bogotá River was constructed using the Salmonella concentration data. The daily probability of illness from eating raw unwashed vegetables ranged between 0.62 and 0.85, 0.64 and 0.86, and 0.64 and 0.85 based on concentrations estimated by qPCR (0.47-0.85, 0.47-0.86, and 0.41-0.85 based on concentrations estimated by direct isolation) for lettuce, cabbage, and broccoli, respectively, which are all above the commonly propounded benchmark of 10-4per year. Results obtained in this study highlight the necessity for appropriate wastewater treatment in the region, and emphasize the importance of postharvest practices, such as washing, disinfecting, and cooking.
authors.affiliation: Department of Civil and Environmental Engineering, Universidad de los Andes, Bogotá, Colombia.
authors.forename: Laura X
authors.initials: LX
authors.lastname: Henao-Herreño
authors.affiliation: Department of Civil and Environmental Engineering, Universidad de los Andes, Bogotá, Colombia.
authors.forename: Ana M
authors.initials: AM
authors.lastname: López-Tamayo
authors.affiliation: Department of Civil and Environmental Engineering, Universidad de los Andes, Bogotá, Colombia.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Ramos-Bonilla
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, Drexel University, Philadelphia, PA, USA.
authors.forename: Charles N
authors.initials: CN
authors.lastname: Haas
authors.affiliation: Department of Civil and Environmental Engineering, Universidad de los Andes, Bogotá, Colombia.
authors.forename: Johana
authors.initials: J
authors.lastname: Husserl
mesh_terms: D057914:Agricultural Irrigation; D001937:Brassica / Q000382:microbiology; D003105:Colombia; D003296:Cooking; D004784:Environmental Monitoring; D005506:Food Contamination; D005843:Geography; D006801:Humans; D018545:Lactuca / Q000382:microbiology; D016133:Polymerase Chain Reaction; D011336:Probability; D018570:Risk Assessment; D045483:Rivers / Q000382:microbiology; D012475:Salmonella; D012480:Salmonella Infections / Q000453:epidemiology*; D014675:Vegetables / Q000382:microbiology*; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014871:Water Microbiology
chemical_list: D062065:Wastewater
keywords: Bogotá River; QMRA; Salmonella