Parasitological Contamination of Wastewater Irrigated and Raw Manure Fertilized Vegetables in Mekelle City and Its Suburb, Tigray, Ethiopia

Abstract

Watering of vegetables in developing countries including Ethiopia is done using untreated wastewater and raw manure of domestic animal origin is used as fertilizer. Thus, vegetables are considered to be the principal  sources of human infection with bacterial, protozoan and helminth parasites. Therefore, the objective of this study was to evaluate the rate of parasitological contamination of pre-harvest vegetables in Mekelle city and its suburban village, ‘Mariam Dahan’. Pre-harvest vegetables were collected from the field during the dry season, washed using physiological saline solution, allowed to sediment overnight, centrifuged and examined microscopically for infective stages of intestinal parasites. Out of the  vegetable samples examined, 32.41% in Mekelle city and 30.49% in  ‘Mariam Dahan’, contained at least one parasitic contaminant. Strongyloides stercoralis was most encountered parasitic contaminant in the study areas, followed by, Taenia and Entamoeba spp. Highest rate of parasitic contamination was detected on Swiss chard, that was 45.5 and 41.67% in Mekelle city and ‘Mariam Dahan’, respectively. Occurrence of infective stages of intestinal parasites on wastewater-irrigated vegetables may pose public health hazards to farming communities in the study  areas. Therefore, evaluation and surveillance of parasitological quality of vegetables is crucial in an attempt to control vegetable-transmitted  parasitic infections.

Keywords: Untreated wastewater, Raw manure, Pre-harvest Vegetables, Parasitological contamination, Tigray, Ethiopia