Contamination of raw vegetables with Cryptosporidium oocysts in markets within Zaria metropolis, Kaduna State, Nigeria

Abstract

Fresh vegetables are an important part of a healthy diet and can be agent of transmission of intestinal parasites. A survey was carried out using 200 fresh vegetable samples in Zaria metropolis, Kaduna State for detection of Cryptosporidium oocysts in vegetables using sucrose flotation medium of 1.21 specific gravity and modified Ziehl Neelsen staining technique. Seventy (35%) out of the 200 vegetables examined were positive for Cryptosporidium oocysts. Lettuce had the highest (48%) contamination rate followed by Fluted pumpkin (44%), spinach and Jute mallow (40%) each, waterleaf (36%), tomatoes (32%), carrot (24%) and cabbage (16%). Sabo market had the highest contamination rate of 21 (37.5%) followed by Samaru 22 (34.4%) and Community market 27 (33.8%). Contamination was highest in leafy vegetables (37.3%), followed by fruit vegetables (32%) and root vegetables (24%). Thirty (30%) out of 100 vegetables consumed raw and 40 (40%) out of those cooked before consumption were positive for Cryptosporidium oocysts. There were no significant associations between occurrence of Cryptosporidium oocysts and the types of vegetables sold (χ2 = 8.70; p = 0.2747), markets in which the vegetables were sold (χ2 = 0.22; p = 0.8959), nature of vegetables (χ2 = 1.79; p = 0.4091) and way in which the vegetables are consumed (odds ratio (OR) 0.64; 95% confidence interval (CI) on OR: 0.34 < OR < 1.20). This study has shown that vegetables sold in markets within Zaria metropolis, Kaduna State, Nigeria, are contaminated with Cryptosporidium oocysts. This is of public health significance.