Role of virus carrying animals in the spread of foot-and-mouth disease disease

УДК 619:616.988.45
DOI 10.33861/2071-8020-2023-3-20-23

Mishchenko A.V., Mishchenko V.A., Krivonos R.A., Chernykh O.Yu., Chernov A.N.

Summary. Foot-and-mouth disease is a typical epizootic infection characterized by polypathogenicity. Foot-and-mouth disease is more contagious than all known infectious diseases, which causes high transmissibility and enormous scale of economic damage. The most important epizootological features of foot-and-mouth disease, as a nosological unit, are due to the pathogenesis of the disease, ecology and biological properties of the pathogen. A feature of foot-and-mouth disease is the formation of a reservation or persistent strain of the pathogen in the convalescence stage from a virulent virus population. At the stage of convalescence, the transition from an acute infectious process to latent viral transmission is recorded against the background of an increase in the level of post-infectious immunity. In vaccinated animals with high levels of post-vaccination antibodies, but who have been in contact with animals with foot-and-mouth disease, viral transmission may be registered. The phase of pathogen reservation takes the end of the epizootic process (period) in time. During this phase, the foot-and-mouth disease virus persists in the body of immunocompromised animals. The facts of the formation of a redundant (persistent) FMD virus population during the infectious process against the background of an increase in the level of post-infectious antibodies were found. In the body of ruminants, the pathogen of foot-and-mouth disease in the interepizootic period remains in a persistent state. The features of persistent infection are: localization of the foot-and-mouth disease virus only in the pharynx, low level of the pathogen in the pharynx, viral transmission after recovery, a sharp decrease in reproductive capacity, transmissible ability of the persistent virus, a decrease in the number of virus carriers in the herd and a progressive decrease in pathogenicity of the pathogen with an increase in the period of convalescence. The causative agent of infection isolated from viruscarrying animals differs significantly from the epizootic virus in terms of infectivity, pathogenicity, transmissible ability, plaque size, ability to reproduce at 42°C, sensitivity to pH 6.5 and temperature 50°C.

Keywords: virus, foot-and-mouth disease, cross-border diseases, virus-carrying animals, cattle, sheep, antibodies, post-vaccination, post-infectious, convalescence stage, reservation virus, persistent, esophageal-pharyngeal fluid.

Author affiliation:

Mishchenko Vladimir A., D. Sc. in Veterinary Medicine, professor, chief scientific researcher of the laboratory for prevention of diseases of pigs and horned cattle of the Federal Centre of Animal Health; mcrd. Yurjevets, Vladimir, 600901; phone: 8-4922-261551; e-mail: mishenko@arriah.ru.

Mishchenko Alexey V., D. Sc. in Veterinary Medicine, professor, senior scientific researcher at the Information and Analytical Center of the Veterinary Supervision Department of the Federal Centre of Animal Health; mcrd. Yurjevets, Vladimir, 600901; phone: 8-4922-261551; e-mail: mischenko@arriah.ru.

Krivonos Roman A., Ph. D. in Veterinary Medicine, docent of the department of parasitology, veterinary-sanitary expertise and zoohygiene of the Kuban State Agrarian University named after I.T. Trubilin; 13, Kalinina st., Krasnodar, 350044; e-mail: uv@krasnodar.ru.

Chernykh Oleg Yu., D.Sc. in Veterinary Medicine, docent, professor of the department of microbiology, epizootology and virology of the Kuban State Agrarian University named after I.T. Trubilin; 13, Kalinina st., Krasnodar, 350044; phone: 8-918-4956659; e-mail: gukkvl50@kubanvet.ru.

Responsible for correspondence with the editorial office: Chernov Albert N., D. Sc. in Biology, Deputy Director for Scientific Work of the Krasnodar Scientific Research Veterinery Institute - a separate structural subdivision of the Krasnodar Scientific Center for Animal Husbandry and Veterinary Medicine; 1, 1 Liniya st., Krasnodar, 350004; phone: 8-927-4036300; e-mail: rt-kazan@mail.ru.