High Intestinal Parasite Contamination in Raw Vegetables Sold in Kathmandu Metropolitan City, Nepal

Objectives: Fresh vegetables are crucial for a healthy diet, providing the body with essential supplements. Intestinal parasites/commensals are transmitted primarily through the consumption of raw contaminated vegetables. This study aimed to investigate intestinal parasite/commensal contamination in randomly selected common and representative fresh vegetable produce sold in various local markets in Kathmandu Metropolitan City, Nepal. Methods: Between August 2023 and February 2024, collected vegetable samples ( n = 250) of carrots, radishes, cabbage, coriander and tomatoes were examined for parasitic contamination via the normal saline sedimentation technique and iodine wet mount following standardised protocols. Parasites/commensals were identified based on morphometric features using standard light microscopy following sedimentation and iodine staining techniques. Results: Of the 250 fresh vegetable samples analysed, 123 (49.2%) were contaminated with at least one intestinal parasite/commensal. The coriander samples presented the highest contamination rate (75.5%), whereas the tomatoes presented the lowest rate (33.3%). Overall, five protozoan parasites/commensals ( Balantidium coli, Entamoeba coli, Eimeria spp ., Giardia duodenalis and Isospora spp.) and six helminthic parasites ( Strongyloides spp., hookworms, Ascaris lumbricoides , Trichuris spp., Hymenolepis spp. and Toxocara spp.) were detected. Notably, Strongyloides spp. was the most common parasite detected (27.2%), followed by B. coli (18%), E. coli (16.8%), hookworms (9.2%), A. lumbricoides (6.4%) and G. duodenalis (5.6%). In addition, 75% contamination of coriander, which is mostly consumed uncooked, was detected, which is alarming. Method of display, vender’s hygiene and method of transportation indicated some role in vegetable contamination. Conclusions: The high rate of parasitic contamination in marketed vegetables underscores the urgent need for a sustainable monitoring system. Furthermore, health education on the safety of fresh vegetables is necessary to safeguard consumer health.