Contamination of Soils with Helminthic Eggs in Some Districts of Duhok Governorate / Kurdistan Region-iraq

Abstract

Duhok Governorate, Kurdistan Region consists of many districts, where there is a high distribution of animals, presences of public parks and pastures. The present study was conducted in some of districts (Duhok center, Semel, Amadyia and Sharya) of Duhok Governorate, Kurdistan Region. The current study amid to determine the contamination of soils with helminthic ova and their correlation with the district residents, type of soil and presence of animals (Mainly stray Dogs and Cats). During this study, 533 soil samples were collected randomly from October 2021 to May 2022.  The samples were collected from different places such as dog shelters, general parks, groves, Hospital parks, near pastures, near sewage, private gardens, school parks, and near slaughter houses.  The collected samples were tested by flotation technique using saturated zinc sulphate (specific gravity 1.2).    The total rate of soil contamination with helminthic ova in all examined samples was 23.45% (125 / 533). The highest contamination rate with these ova was reported in soil samples examined from Sharya Camp 53.57% (30/56), while the lowest contamination rate was from Semel district 19.22% (49/255). The rates of ova in soils collected from Amadyia and Duhok center were 23.61% (34/144) and 15.38% (12/78), respectively. Regarding to the locations, soil samples examined from rural areas revealed high rate of contamination 29.33% (107/366) as compared with urban areas, in which the rate was 10.78% (18/167). The contamination rates with helminthic ova according to the type of soil, in clay soil was 26.54%, while in silty and sandy soils were 24.39% and 14.96%, respectively. The contamination rate of soils with these ova was higher in areas populated with animals mainly dogs and cats which was 26.44% (78/295) as compared to areas free from animals 19.75% (47/238) (19. Regarding to different places, the results showed that soils in places close to the sewage were highly contaminated with ova 50.00% (3/6), followed by those near pasture 37.50% (15/40), groves 35.56% (16/35), dog shelters 32.18% (28/87), school Parks 29.41% (10/34), near slaughter houses 27.50% (11/40), public places 21.05% (32/152). On the other hand, the lowest contamination of the soil with these ova was recorded in private gardens 8.26% (10/121), while the soil samples from hospital parks were free from parasitic ova. According to the type of helminths, ova of 6 helminthic genera were reported in all (533) examined soil samples, with Toxocara ova being the most prevalent helminths detected in 34 (6.38%), samples, then ova of Hymenolepis nana in 32 (6.00%), Taeniid ova in 26 (4.88%), Ancylostoma ova in 15 (2.81%), Ascaris ova in 12 (2.25%), and Trichuris ova in 6 (1.13%).  In conclusion, the soils of some districts were contaminated with different types of helminthic eggs. Therefore, the people of these districts will be at a high risk of acquiring infection with different species of these parasites when they get contacts with the soil