Prevalence of Toxocara Species Eggs in the Soil of Public Parks in Hamedan City, Western Iran

Toxocariasis is one of the most commonly reported zoonotic helminth infections in the world which is caused by the parasitic roundworms of dogs or cats. This survey aimed to provide data on the contamination of the soil of public parks by Toxocara spp. eggs in Hamedan city, capital of Hamedan Province in the west of Iran.

During April and May 2019, a total of 120 soil samples were collected from 20 public parks (4 to 10 soil samples from each park) from all geographical areas of the city. For detection of eggs, soil samples were dried overnight at room temperature and passed through a 150 μm mesh sieve. After performing Sheather’s flotation technique using 2 g of powdery soil, light microscopic examinations were carried out.

Microscopic evaluation of specimens revealed that 14 samples out of 120 (11.67%) collected from 10 public parks out of 20 in Hamedan (50.0%) were contaminated with Toxocara spp. eggs. Various developmental stages of Toxocara spp. eggs including (1) non-developed, (2) 2-cell to tadpole stage, and (3) larvated eggs were observed. Furthermore, in two public parks, Trichuris spp. eggs were found in the soils.

This study provides the first information about the contamination of public areas in Hamedan 0rovince and suggests that public awareness about this fact is needed. Education of citizens especially parents with children, who have commonly mouthing behavior, is recommended. Further molecular-based studies for the identification of parasite species in the province are suggested. All of the published literature about contamination of the soils of public areas in Iran with Toxocara eggs until July 2020 were also reviewed.