Parasitic Contamination of Fruits and Vegetables from Open Markets in Oyo Town, Nigeria

Abstract

Parasitic contamination of fresh produce poses a significant public health risk, particularly in developing countries where sanitary conditions are often inadequate. This study investigated the prevalence of intestinal parasites in a cross-sectional analysis of 420 fruit and vegetable samples from three major markets in Oyo Town, Nigeria, between April and July 2025. Samples were randomly obtained from vendors and analyzed using sedimentation and microscopic examination techniques. Data were evaluated with chi-square tests, Kruskal-Wallis H-tests, and hierarchical clustering. A high overall prevalence of 36.43% was observed, with significant variation across markets (χ² = 62.71, p< 0.001), where Ajegunle recorded the highest contamination rate (59.3%) and Akesan the lowest (13.6%). Six parasite species were identified, comprising protozoa, helminths, cestodes, and trematodes. Parasitological examination revealed a diverse range of parasites, with Ascaris lumbricoides being the most dominant species. The distribution of parasites was also found to be produce-specific, with Trichuris spp. most prevalent in carrots and Ascaris spp. in tomatoes, differences that were statistically significant (p < 0.001), signifying distinct risk profiles for different commodities. Market-level differences were also significant, with refuse dump proximity, poor drainage, and inadequate hand hygiene identified as key contributing factors. These findings indicate widespread faecal contamination and poor hygienic practices throughout the food supply chain, stressing an urgent need for targeted public health interventions and stringent food safety regulations to mitigate the risk of foodborne parasitic infections. Keywords: Food safety, fresh produce, intestinal parasites, Nigeria, parasitic contamination, public health, Shannon diversity index