Parasitic contamination of commonly consumed vegetables in two markets in Ghana

Abstract

Introduction: 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.

Method: 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.
Result: 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.

Conclusion: 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.

Funding: Ensign College-Students Research Award Program of Bob and Lynette Gay

Keywords: Parasites, contamination, vegetables, market, Ghana