Soil Contamination with Eggs of Toxocara spp. in Yazd, Central Iran

Soil contamination with Toxocara spp. eggs is the main source of human toxocariasis. The aim of this study was to determine rate of soil contamination with Toxocara spp. eggs in Yazd, central Iran.

During September 2014 to February 2015, a total of 220 soil samples were collected from public parks, primary schools, green areas, kindergartens, suburban areas, streets, residential complexes, backyards and a bus terminal in the city of Yazd, Yazd Province. Soil samples were investigated for the presences of Toxocara eggs by flotation technique using sucrose solution (1.2 g/cm3) and using light microscopy. Data analysis was carried out by SPSS (version 23) software package.

A total of 220 soil samples from nine different places were examined. Of these samples, 51 (23.2%) were contaminated with Toxocara spp. eggs. The contamination rate was 26.3% in public parks, 19.2% in primary schools, 28.6% in green areas, 22.2% in kindergartens, 24% in suburban areas, 8.3% in streets, 18.8% in residential complexes, 19% in backyards and 28.6% in the bus terminal. There was no significant difference in the soil contamination rate with Toxocara spp. eggs between different sampling places (χ2 = 3.096, d.f = 8 and P= 0.92) and sampling areas (χ2= 2.289, d.f = 2 and P= 0.318).

The high rate of soil contamination with Toxocara spp. eggs in Yazd emphasize on the need for preventive measures, such as improving sanitation, providing public health education and controlling stray dogs and cats near children play areas.