Parasitic contamination of environmental objects (based on materials of Center for Hygiene and Epidemiology in Astrakhan region)

Objective. To study the sanitary and parasitological state of environmental objects in Astrakhan region.

Materials and methods. A total of 45,475 samples taken from various environmental objects in Astrakhan region were analyzed. The number of unsatisfactory samples was 1.1 % (484 samples).

Results. For the period from 2015 to 2019, there were studied the following samples: soil – 12.5 % (5518 samples), water – 6.9 % (3026 samples) and flushes from solid household surfaces – 80.6 % (35501 samples).

The percentage of washout samples from hard surfaces was 80.6 % (35,501 samples). The number of unsatisfactory samples was 0.003 % (1 sample). In this sample, teniid oncospheres were detected in 2019. The share of water samples was 6.9 % (3026 samples). Positive findings in the form of helminth eggs and larvae, as well as cysts of pathogenic intestinal protozoa were 3.1 % (93 samples). In addition to samples taken from environmental objects, samples of food raw materials and food products were studied – 3.1 % (1430 samples). The number of unsatisfactory samples was 4.6 % (66 samples). In these samples there were found: larvae of Strongyloides stercoralis – 84.8 % (56 samples), eggs and metacercariae of Opisthorchis felineus – 4.5 % (3 samples), cysts of Entamoeba histolytica, larvae of Strongyloides stercoralis + Ascaris lumbricoides – 3.0 % for each (2 samples for each), eggs of Ascaris lumbricoides and Enterobius vermicularis – 1.5 % (1 sample) and larvae of Strongyloides stercoralis + Toxocara Canis – 1.5 % (1 sample).

Conclusions. The presence of mobile strongylid larvae and toxocar eggs in the soil indicates contamination of this object with the feces of invaded animals, and the presence of ascariid eggs, opisthorchis, dwarf tapeworm, teniid oncospheres and dysentery amoeba cysts in the soil indicates contamination with the feces of invaded people. The presence of eggs and larvae of helminths characteristic of animals and humans in samples taken from open reservoirs indicates, first of all, the contamination of these objects with the feces of infected people and/or animals, as well as the presumed version of water contamination with sewage. The presence of Toxocara eggs and strongylid larvae on the samples of fruit and vegetable products indicates soil contamination with the feces of invasive animals. The presence of ascarid eggs on the food indicates contamination of the soil with the feces of infested people.