Ecosystemic epidemiological, epizootological, and sanitary-hygienic assessment of human and animal echinococcosis in the North Caucasus region

Introduction. Echinococcosis in animals and humans is a planetary problemю. One of those zoonoses have acquired the status of epidemiological and sanitary-hygienic risks for the health in various social groups of the population and animals of more than 80 species.

The purpose of the work is an ecosystemic epizootological, epidemiological, and sanitary-hygienic assessment of animal and human echinococcosis in Karachay-Cherkessia.

Materials and methods. The studies were carried out in 2014–2022. The objects of study were the intestines of eighteen dog corpses slaughtered in compliance with the International Rules for Humane Treatment of Animals (2012), and the liver and lungs of 150 slaughtered sheep. Monitoring of echinococcosis in dogs and sheep was carried out by the method of complete helminthological dissection of organs and tissues according to K.I. Scriabin (1928). The number of taeniid-type eggs in the faeces of dogs and in 500 water samples of the basin of the river Kuban was determined according to the guidelines of Temporary norms and rules (1986). Data on the incidence of cystic echinococcosis in the population are summarized on the base of a comparative analysis of quarterly and annual reports of the sanitary medical services in 7 subjects of the North Caucasus Federal District with the materials of the State reports of the Federal Service for Supervision in Protection of the Rights of Consumer and Man Wellbeing of Russia.

Results. The index of occurrence of invasion of the cystic form of echinococcus in the liver, lungs, and spleen in sheep in the planar zone was 18%, in the foothill zone — 24%, in the mountain zone — 28% (on average, about 25%). Transparent cysts of echinococcus extracted from the liver, lungs, and other organs of sheep contained protoscolexes in 100% of the samples, which indicates the likelihood of natural foci involving dogs and wild predators in the region, violations of the terms of deworming of priotary dogs, lack of sanitary and preventive work among the population. The region belongs to the group of subjects with low rates of zoonoses due to effective anti-epidemic measures. At the same time, the natural reservoirs of Karachay-Cherkessia are natural biotopes of taeniosis, where the contamination of water samples with taeniid eggs ranges from 11 to 37%.

Limitations. The study is limited only by the analysis of statistical data on human echinococcosis in Karachay-Cherkessia and other subjects of the North Caucasus Federal District; other densely populated regions of the Russian Federation have not been studied and not affected.

Conclusion. According to the epidemic situation in terms of echinococcosis in the population, the Karachay-Cherkess Republic can be attributed to relatively prosperous regions of Russia, but to the zone of epidemiological risk, since there is an increase in the number of dogs with tape echinococcosis and sheep infected with fertile cysts. Sanitary and hygienic pollution of the river Kuban and its tributaries with eggs of cestodes is a threat to the spread of echinococcosis among animals and humans.

Compliance with ethical standards. The study does not require the submission of the opinion of the biomedical ethics committee or other documents, as it is based on our own research and on the analysis of the State reports of Rospotrebnadzor of the Russian Federation and annual reports of medical services of the subjects of the North Caucasus Federal District (free access Garant).

Contribution:
Arkelova M.R. — concept and design of the study;
Bittirov A.M. — concept and design of the study, preparation of the manuscript;
Bolatchiev K.Kh. — data collection, literature review;
Gogushev Z.T. — analysis and interpretation of results;
Bittirov I.A. — analysis and interpretation of the results.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The study had no sponsorship.

Received: March 28, 2023 / Accepted: June 7, 2023 / Published: July 30, 2023