High contamination of soil with Toxocara spp. eggs in the north of Iran.

Toxocarosis is an important emerging zoonotic disease, which is caused by larvae of Toxocara canis and Toxocara cati, the most widely distributed nematode parasites of dogs and cats. The soil, where Toxocara eggs become infective, is the natural source of infection. The aim of this work was to determine the levels of soil contamination with Toxocara spp. eggs in Sari district, north of Iran, in order to estimate the risk of infection of the population living in this region. A total of 141 soil samples were collected from 12 parks, 12 primary schools and 45 backyards from three regions. Soil samples were investigated for the presence of Toxocara eggs by flotation technique using sucrose solution and examined under light microscope using 10× and 40× objective. Out of 141 soil samples, 67 (47.5%) were found to contain Toxocara spp. eggs. The contamination rate in public parks, primary schools and backyards were observed 50%, 58.3% and 33.3%, respectively. The comparison of soil contamination rate from different areas, public parks, primary schools and backyards, was statistically significant (χ2=6.00, d.f.=2 and P=0.049). The public parks, backyards and primary schools, which are main places that children play, are suitable for defecation of dogs and cats. The knowledge of the soil contamination with Toxocara eggs indicates the need to take an appropriate and effective measures to prevent the infection.