Prevalence of Coccidians and Helminthes Ova in Soil Samples from Public Places in Isfahan City, Iran, 2016

Soil contamination with parasites is a serious risk for parasitic infections in humans and animals. Because of the importance of soil, as an important source for transmission of parasites to humans and animals, this study was carried out to determine the prevalence of various forms of parasite oocytes and helminthes ova.
A total of 150 soil samples were collected from 150 sites in public places of Isfahan City, Iran, in 2016. Isolation of parasites from the soil was performed by saturated solution of sodium nitrate. Then, the samples were observed under microscope and positive isolates to sporulation and better recognize, were poured in 3% potassium dichromate. All the isolates were studied for further investigations with acid-fast specific staining.
Findings: from 150 samples, 84 were positive and the rest were free of any contamination. 33 samples had multiple simultaneous contaminations. 2 samples were positive for Toxoplasma gondii oocytes, 12 samples for Isospora sp. oocytes, 6 samples for Eimeria sp. oocytes, 10 samples for Cryptosporidium sp. oocytes, 13 samples for Toxocara canis oocytes, 6 samples for Toxocara cati oocytes, 4 samples for Toxascaris leonina oocytes, and 65 samples for larvae of soil nematodes.
Soil is considered as an important potential source in transmission of parasitic infections. Environmental hygiene is required for prevention of soil pollution and control of soil-borne parasitic infections especially. According to our study, the prevalence of parasites in the soil is decreased.