Evaluation of Vegetable Contamination with Medically Important Helminths and Protozoans in Calabar, Nigeria

Aims: Vegetables are usually exposed to parasitic ova, larvae or oocyst during cultivation, irrigation, storage, transportation or while processing for consumption. Consumption of raw, unwashed and improperly cooked vegetables is considered a risk factor for transmission of intestinal parasites. This study assessed the parasitic contamination of vegetables and also determined factors associated with parasitic contamination of vegetables in selected markets in Calabar, Cross River State.

Place and Duration of Study: Sample: Markets within Calabar, Cross River State, Nigeria between September and October, 2018.

Methodology: A pre-tested semi-structured questionnaire was used for collecting data on factors associated with parasitic contamination of vegetables. 300 vegetable samples were purchased and processed from three different markets in Calabar for examination of parasitic contamination using direct wet mount and zinc sulphate floatation techniques.

Results: 15.7% (47/300) of the vegetables sampled were positive for at least one parasite. The species and stages of parasites detected were larvae of Strongyloides, ova of Trichuris trichiura and Hookworm, and cysts of Entamoeba histolytica and Giardia lamblia. Larvae of Strongyloides (11.3%) were the most frequently detected followed by ova of T. trichiura (1.7%) and Hookworm (1.7%) (P = 0.000). Among the five vegetable types sampled, waterleaf (40%) had the highest level of parasitic contamination followed by pumpkin (21.7%). Washing vegetables before display and the means of display were significantly associated with parasitic contamination (P = 0.000).

Conclusion: Prevention of contamination is important in reducing food-borne parasitic infections and can be achieved through improved personal hygiene practices of farmers, vendors and consumers, proper washing of vegetables and improved sanitary conditions especially around markets where these vegetables are sold.