Parasitological Assessment of Salad Vegetables Sold in Markets in Onitsha, Anambra State, South East Nigeria

Raw salad vegetables constitute an important dietary component and a recognised vehicle for the transmission of foodborne parasitic infections when contaminated with soil, water, or human excreta during cultivation, harvesting, or marketing. This study evaluates the parasitological contamination of salad vegetables sold at major markets in Onitsha, Anambra State, South East Nigeria. A cross-sectional market survey was conducted, collecting samples of lettuce, garden egg, cucumber, green pepper, and tomatoes from three markets in Onitsha North and South Local Government Areas. Vegetable samples were washed in phosphate-buffered saline solution, and sediments were examined microscopically using wet mount and formal-ether concentration methods for helminth ova, cysts, and oocysts. Vendor interviews assessed sources of irrigation water, storage conditions, and handwashing practices. Recent studies from 2020 to 2024 identify leafy vegetables grown with wastewater irrigation in southern Nigerian markets as frequent carriers of Ascaris, Trichuris, Giardia, and Cryptosporidium. This study will generate prevalence data stratified by vegetable type and market, and identify source characteristics associated with higher contamination risk. Findings will be communicated to the Anambra State Ministry of Trade and Commerce and the Onitsha Market Association for initiating vendor food safety training. Keywords: vegetable contamination, foodborne parasites, market survey, Onitsha, Anambra State.