Parasitic contamination of commonly consumed vegetables in two markets in Ghana.

Catherine Kudah,Simon Sovoe,Frank Baiden

doi:10.4314/gmj.v52i2.5

Abstract

Fresh vegetables are an important source of vital nutrients. Poor farming practices and improper washing put consumers at risk of parasitic infections. This study explored the presence of parasitic contamination of commonly-consumed vegetables procured from two markets in Ghana. It also explored the decontamination effects of washing vegetables with different concentrations of saline solution. Vegetables were procured from two major open markets in Koforidua, Ghana. Vegetables were thoroughly washed twice using 0.0%, 0.45%, 0.9%, 1.5% concentrations of saline solutions. The deposits were examined under the light microscope for the presence of parasites. Smears were made from sediments, stained and observed with Fluorescence microscope to detect any spores or oocysts of Microsporidium sp., and Cryptosporidium sp. Three hundred and sixty of five types of vegetables were procured. Two hundred and seven (57.5%, 95% Confidence Interval 52.2% - 62.7%) were found to be contaminated with at least one type of parasite. The extent of vegetable contamination was 97.2% (90.3-99.7) of spring onions, 70.8% (58.9-81.0) of lettuce and 50.0% (38.0-62.0) of tomatoes. The commonest parasites were Strongyloides stercoralis (36.4%, 31.4-41.6), Balantidium coli (13.6%, 10.2-17.6) and Cryptosporidium oocyst (11.1%, 8.1-14.8). Parasite recovering rates were 57.5% (52.2-62.7) and 42.2% (37.1-47.5) after first and second washings respectively. The level of parasite contamination is high and consumption of raw vegetables procured from these markets carry a high risk of parasite infection. Washing vegetables twice with saline was not effective for parasite removal. Improved approaches for washing vegetables before consumption are needed. Ensign College-Students Research Award Program of Bob and Lynette Gay.

Highlights

Fresh vegetables are a major source of vital nutrients
Bad hygienic practice during transport, processing and preparation by handlers including consumers could contribute to vegetable contaminations
This study explored the presence of parasitic contamination of commonly-consumed vegetables procured from two markets in Ghana and examined the extent to which washing with different concentrations of saline solutions is able to remove the contaminants

Summary

Introduction

Fresh vegetables are a major source of vital nutrients. Consumption is promoted for the vitamins, minerals, dietary fiber, and antioxidants it provides. Traditional practices in the cultivation, manuring and harvesting of vegetables in many parts of sub-Saharan Africa remains an area of concern. The use of sewage and other form of liquid waste during cultivation are potential source of contamination with the eggs and larvae of parasitic infections. Human infection occurs through consumption of raw vegetables.[1, 2]. Epidemiological studies have indicated that in areas of the world where helminthic diseases are endemic and where raw untreated waste water is used to irrigate vegetables generally eaten uncooked, the consumption of such waste irrigated vegetables may lead to parasitic infestation.[3] Bad hygienic practice during transport, processing and preparation by handlers including consumers could contribute to vegetable contaminations. Other factors which affect the susceptibility of the public to foodborne diseases include food consumption patterns, such as the increase in the number of people eating meals prepared in restaurants, canteens and fast food outlets as well as from street food vendors who do not always observe optimal food safety

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