Assessment of soil biocontamination with toxocara eggs in urbanized ecosystems

Toxocariasis in the Russian Federation is the most dangerous of the common helminthiases that can affect dogs or cats. Toxocariasis is a zoonotic geohelminthiasis, which is naturally transmitted from vertebrates to humans and poses a threat to people as a source of infection in megacities. In order to study the prevalence of toxocars among domestic and stray dogs living in the urbanized ecosystems of the Kirov region, the study of dog excrement by the flotation method has been carried out for 3 years. The results of the research show that, on average, in the village of Zagarye of the Yuryansk region, the amount of the dogs infected with toxocariasis is 64%, in the yards and children's playgrounds - 76.6%. In the parks of Kirov, the amount of infected dogs is 28.0 ± 2.3% and 21.0 ± 3.6%, respectively. The calculated values of soil biocontamination in the parks of Kirov per day are 1948.64 and 1205.0 thousand eggs, in the village of Zagarye - 161,014.0 thousand Toxocara eggs. During the year, these values reach astronomical values: 711 253, 6 thousand, 439 854.0 thousand and 58 770 110.0 thousand toxocara eggs, respectively. The high prevalence rates of infection with Toxocara spp. among stray and domestic animals create conditions that can lead to constant pollution of urbanized ecosystems and cause a tense ecological and epidemic situation in the city. © The Authors, published by EDP Sciences, 2021.