title: A probabilistic assessment of the contribution of wastewater-irrigated lettuce to Escherichia coli O157:H7 infection risk and disease burden in Kumasi, Ghana.
abstract: Wastewater use for vegetable production is widespread across the cities of many developing countries. Studies on the microbial health risks associated with the practice have largely depended on faecal indicator organisms with potential underestimation or overestimation of the microbial health risks and disease burdens. This study assessed the Escherichia coli O157:H7 infection risk and diarrhoeal disease burden measured in disability-adjusted life years (DALYs) associated with the consumption of wastewater-irrigated lettuce in Kumasi, Ghana using data on E. coli O157:H7 in ready-to-harvest, wastewater-irrigated lettuce. Two exposure scenarios - best case and worst case - associated with a single consumption of wastewater-irrigated lettuce were assessed. The assessment revealed wastewater-irrigated lettuce is contributing to the transmission of E. coli O157:H7 in Kumasi, Ghana. The mean E. coli O157:H7 infection risk and DALYs in the wet and dry seasons, irrespective of the exposure scenario, were above the World Health Organization tolerable daily infection risk of 2.7 × 10⁻⁷ per person per day and 10⁻⁶ DALYs per person per year. It is recommended that legislation with clear monitoring indicators and penalties is implemented to ensure that farmers and food sellers fully implement risk mitigating measures.
authors.affiliation: Water Sanitation Engineering and Health Group, Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway E-mail: razseidu@yahoo.co.uk; Water and Wastewater Group, Faculty of Engineering and Natural Sciences, Ålesund University College, Ålesund, Norway.
authors.forename: Razak
authors.initials: R
authors.lastname: Seidu
authors.affiliation: Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Amina
authors.initials: A
authors.lastname: Abubakari
authors.affiliation: Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Isaac Amoah
authors.initials: IA
authors.lastname: Dennis
authors.affiliation: Water Sanitation Engineering and Health Group, Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway E-mail: razseidu@yahoo.co.uk.
authors.forename: Arve
authors.initials: A
authors.lastname: Heistad
authors.affiliation: SARChI Chair, Institute for Water and Wastewater Technology, Durban University of Technology, P.O. Box 1334, Durban 4000, South Africa.
authors.forename: Thor Axel
authors.initials: TA
authors.lastname: Stenstrom
authors.affiliation: Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: John A
authors.initials: JA
authors.lastname: Larbi
authors.affiliation: Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Abaidoo
mesh_terms: D000383:Agriculture / Q000379:methods*; D003967:Diarrhea / Q000453:epidemiology; D004927:Escherichia coli Infections / Q000453:epidemiology*; D019453:Escherichia coli O157; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D018545:Lactuca / Q000382:microbiology*; D018570:Risk Assessment; D062065:Wastewater
chemical_list: D062065:Wastewater