Parasitological investigation of soil biotope in the territory of Moscow

The purpose of the research is to conduct a sanitary and parasitological examination of soil biotopes on the territory of Moscow. In addition to traditional soil studies, we conducted coproscopic analyzes of samples of dog feces collected from the soil surface in Spring.Materials and methods. 83 combined soil samples were taken in 9 administrative districts of Moscow using the envelope method at a depth of up to 10 cm. From each combined sample, 4 samples were taken and examined using the Romanenko method according to MUK 4.2.2661-10 “Methods of sanitary and parasitological research”. From the same areas where soil was collected, 365 dog fecal samples were collected. Feces were studied using a combined flotation method. Soil and fecal samples were taken in Spring of 2023 during a period of positive temperatures immediately after the snow melted. Microscopy was performed using a Motic BA410T microscope. Identification of the detected objects was carried out on the basis of morphometric data. Species differentiation of Toxocara canis and T. cati eggs was carried out based on differences in the size of the eggs and the structure of the outer shell.Results and discussion. The city's soil is contaminated with pathogens of parasitic diseases in 9.3% of samples. Toxocara eggs were found (5.7%), of which T. canis in 3.9% of samples, and T. cati in 1.8% of samples. Eggs of Capillaria sp. detected in 1.5%, eggs of Trichuris sp. at 0.9%. Eggs of Hymenolepis sp. and coccidia were detected in 0.6% of samples. In dog feces, pathogens of parasitic diseases were detected in 3.3% of samples. Toxocara sp. eggs were found in 1.4% of samples, isospores in 0.8%, sarcocystis in 0.8%, Toxascaris leonina eggs in 0.3%. Toxocara sp. eggs are the leaders in the frequency of detection in the soil; these are mainly viable eggs with larvae. This is consistent with the data that T. canis eggs are most often recorded in anonymized dog feces. Eggs of Trichuris sp. and Capillaria sp. found in soil with formed viable larvae. The findings show the potential of urban soils as a parasite transmission factor for humans and susceptible animals, and dogs play a leading role in the contamination of urban soils with Toxocara sp. eggs.