Objective. To study the parasitic contamination of the soil in Astrakhan Region based on the materials of the Center for Hygiene and Epidemiology in Astrakhan Region for 20162020. Materials and methods. The research work was carried out on the basis of the Department of Infectious Diseases and Epidemiology of Astrakhan State Medical University of the Ministry of Healthcare of the Russian Federation, the Sanitary Department of the Center for Hygiene and Epidemiology in Astrakhan Region as well as the Department of Rospotrebnadzor in Astrakhan Region. Results. In total, during the analyzed period, 4243 soil samples were selected and examined from various places in the territory of Astrakhan Region, 8486 studies were performed. The number of samples, which do not meet sanitary and parasitological standards, was 5.6 % (237 samples). The samples of soil were taken in places, regulated by normative documents, according to instructions of the Department of Rospotrebnadzor in Astrakhan Region including places of crop production (collective farms, state farms, agricultural lands) 1.7 % (71 samples), the zone of industrial enterprises, transport highways, places of application of pesticides and mineral fertilizers 4.7 % (198 samples), the territories of livestock complexes and farms 3.7 % (157 samples), the residential zone (the territory intended for residential, public (public-business) and recreational zones as well as separate parts of engineering and transport infrastructure, other objects, the placement and activity of which does not have an impact requiring special sanitary protection zones) 86.8 % (3682 samples), including the territory of children's institutions and playgrounds (kindergartens, orphanages) 83.5 % (3076 samples) of the number of all the examined selected and investigated samples from the residential zone, places of locations of water sources 0.8 % (36 samples) as well as the territories of other objects of supervision (medical and preventive institutions, beaches, places for development etc.) 2.3 % (99 samples). Conclusions. Contamination of the soil with eggs and larvae of geohelminths (toxocara eggs and strongylid larvae) indicates contamination of these objects with feces of invaded animals (the role of stray animals (dogs) in soil contamination is not excluded). The contamination of the soil with eggs of ascaris, opisthorchis, oncospheres of teniids and cysts of amoebas suggests that these objects are contaminated with sewage water resulting from accidents.

The aim of the study is to analyze the clinical and epidemiological aspects of enterobiosis in preschool children. Materials and methods. The material for the study was the data of outpatient records of 164 patients with laboratory-confirmed enterobiosis aged 9 months to 17 years. Results. Of the 164 children who sought medical help, more than half — 54.9 % — were children of preschool age. The majority of children — 86.7 % were from organized collectives (nurseries, kindergartens). The reasons for the examination of children were diverse. More than half of cases of enetrobiosis (55.4 %) were detected in children according to the results of preventive examinations in children's institutions. Another part of the children — 43.4 % — sought medical help due to the presence of clinical symptoms and complaints. And only in a single case — 1.2 % — the child was examined as a contact with a sick family member. When collecting an epidemiological history, it was found that 58 % had geophagia (eating the earth), 30.1 % had onychophagia (the habit of biting nails). 7.2 % of the surveyed children and their parents indicated non-compliance with the rules of personal hygiene (the habit of not washing their hands before eating). 12 % of children had contact with pets (cats and dogs), including 4.8 % with dogs and 1.2 % with cats. Clinical manifestations of the disease, as a rule, occurred in children who sought medical help (50.1 %), and were not detected as a result of a preventive examination. All patients with enetrobiosis received therapy with albendazole and pyrantel in accordance with the instructions for these drugs. Conclusion. According to the results of the study, a wide prevalence of enetrobiosis was revealed among preschool children attending organized collectives. The main risk factors are bad habits, such as geo- and onychophagy, as well as lack of hand washing skills before eating. The most effective measures for the prevention of this parasitosis are timely periodic preventive examinations and hygienic training of preschool children.

Objective. To study and analyze the contamination of environmental objects in the Astrakhan Region (by the example of soil, water, and washout samples from solid household surfaces) based on the results of laboratory studies of the Center for Hygiene and Epidemiology in the Astrakhan Region for 20112020. Materials and methods. The work was carried out on the basis of the Laboratory of Bacteriological and Parasitological Research of the Center for Hygiene and Epidemiology in the Astrakhan Region and in the laboratories of the Branches of the Center for Hygiene and Epidemiology in the Astrakhan Region in 20112020. As a whole, during the analyzed period, the laboratory and its branches conducted laboratory studies of 79 742 samples taken from various environmental objects, and 94 495 studies were performed. The number of samples that do not meet the hygiene standards was 1.01 % (806 samples). Results. The objects of sampling for the study of their parasitic purity were water, soil and wash-out from solid household surfaces. The share of water samples in the structure of all the studied samples taken from environmental objects was 7.3 % (5858 samples), of which 172 samples were contaminated with pathogens of parasitic diseases, the extent of invasion was 2.9 %. The structure of positive findings in the water samples was represented by 6 nosological forms of helminths 88.0 % (154 samples) and 3 nosoforms of protozoa 12.0 %. The share of the studied soil samples in the overall structure of sanitary and parasitological studies of the environment was 11.2 % (8895 samples). The number of unsatisfactory samples in the structure of all positive findings revealed during the study of soil, water and washouts during the analyzed period was 70.4 % (625 samples). The total soil contamination for the period of 20112020 was 7.0 % (625 samples). In most cases, helminth eggs and larvae were detected 99.8 % (624 samples). The proportion of pathogenic protozoan cysts detected in the soil was 0.2 % (1 sample). In addition to water and soil samples, the washout samples, taken from solid household surfaces were studied 81.5 % (64989 samples), of which 0.01 % (9 samples) were unsatisfactory. All positive findings in the washout samples were represented by two nosological forms of helminthiasis: Enterobius vermicularis eggs 0.012 % (8 samples) and teniid oncospheres 0.002 (1 sample). Conclusions. The presence of helminth eggs and cysts of pathogenic intestinal protozoa in the studied soil and water samples indicates contamination of these objects with the feces of infected persons and/or contamination by sewage runoff resulting from various accidents. The presence of toxocara eggs and strongylid larvae in the soil and water indicates contamination of these objects with the feces of infected animals (dogs, cats). The presence of positive findings in wastewater samples indicates poor-quality disinfection of these objects. The presence of contact helminth eggs in the studied samples of washout samples taken from hard surfaces indicates direct contact of infected persons with these samples.

The purpose of the study. To analyze the parasitic contamination of the Astrakhan soil with eggs and larvae of helminths. Materials and methods. A total of 438 soil samples were selected and examined during the analyzed period, of which 21.2 % (n=93) did not meet the indicators of parasitic safety. The following helminth eggs and larvae were found in these samples: dead Strongyloides stercoralis larvae — 77.4 % (n=72), Toxocara canis eggs — 10.8 % (n=10) and Askaris lumbricoides — 11.8 % (n=11). The results of the study. The largest number of soil samples selected for the study for the presence of eggs and larvae of helminths and cysts of pathogenic intestinal protozoa was investigated among the playgrounds of the city of Astrakhan and amounted to 71.9 % (n=315) of all studied soil samples for the analyzed period. The number of positive findings in these soil samples was 14.9 % (n=47). In this case, dead Strongyloides stercoralis larvae were found in 97.9 % (n=46) of samples and unfertilized Askaris lumbricoides eggs — in 2.1 % (n=1). In addition to the soil from playgrounds, we selected and examined the soil from the territories of parks and squares. Thus, during the analyzed period, 13.2 % of samples were examined (n=58), of which 36.2 % (n=21) did not meet hygienic standards as dead larvae of Strongyloides stercoralis — 53.4 % (n=11) and Toxocara canis eggs — 46.6 % (n=10) were found in these samples. Also, we examined the soil from the territories of urban beaches — 8.0 % (n=35), of which 28.6 % (n=10) did not correspond to the norm. In all cases, dead Strongyloides stercoralis larvae were found in the samples. In addition to playgrounds, beaches, and recreation areas for citizens and guests of the city, we conducted a study of soil taken from the territories of higher educational institutions, of which half of the samples — 50.0 % (n=15) did not meet the norm for parasitological indicators. Unfertilized Askaris lumbricoides eggs (66.7 %) and dead Strongyloides stercoralis larvae (33.3 %) were found in these soil samples (n=5). Conclusions: the largest number of unsatisfactory soil samples was noted in 2018, when dead Strongyloides stercoralis larvae, Toxocara canis eggs and unfertilized Askaris lumbricoides eggs were found; the presence of Toxocara canis eggs and dead Strongyloides stercoralis larvae in the soil indicates contamination of this object with the feces of infected animals; the presence of unfertilized Askaris lumbricoides eggs in soil samples taken from playgrounds and beaches of the Astrakhan city shows the contamination of these objects with the feces of infected people; the presence of unfertilized eggs of Askaris lumbricoides in soil samples taken from the territory of higher educational institutions and parks in Astrakhan indicates accidents on the sewer network.