Classical swine fever: a retrospective analysis of the epizootic situation in the Russian Federation (2007–2021) and forecast for 2022

The paper presents trends in the epizootic situation on classical swine fever (CSF) in the Russian Federation, for 2007–2021. Most likely, a drop in the number of CSF outbreaks throughout the country results from two factors: a geographical shift of the disease outbreaks from the European part of Russia to the eastern regions bordering on China (into the wild boar population), as documented between 2015 and 2021, and a large-scale vaccination of domestic pigs practiced in the recent years. The introduction and spread of CSF in the Russian Federation are, most likely, associated with the internal risk factors (i.e. quality of anti-epizootic measures, mainly vaccination) and with the territories, where the virus circulates in wild boars. Expansion of vaccination coverage since 2011 is one of the factors contributing to a decrease in the number of clinical CSF cases registered in domestic pigs of the Russian Federation. The infection spread in domestic pigs is still on a downward trend. For purposes of analysis, current trends of CSF spread in domestic pigs and wild boars in the Russian Federation, as well as the volume of the vaccine used, were visualized in relative numbers (taking into account total number of pigs in the country) used to build a regression model. Currently, vaccination against classical swine fever in the Russian Federation (and its good quality) is an essential prerequisite to contain the infection spread in the country.

1. Infectious pathology of animals: 2 volumes. Vol. 1. Ed. by A. Ya. Samuylenko, B. V. Solovyov, Ye. A. Nepoklonov, Ye. S. Voronin. Moscow: Akademkniga; 2006. 911 p.

2. Coronado L., Perera C. L., Rios L., Frías M. T., Pérez L. J. A critical review about different vaccines against classical swine fever virus and their repercussions in endemic regions. Vaccines (Basel). 2021; 9 (2):154. DOI:10.3390/vaccines9020154.

3. Fan J., Liao Y., Zhang M., Liu C., Li Z., Li Y., et al. Anti-classical swine fever virus strategies. Microorganisms. 2021; 9 (4):761. DOI:10.3390/microorganisms9040761.

4. Blome S., Staubach C., Henke J., Carlson J., Beer M. Classical swine fever – An updated review. Viruses. 2017; 9 (4):86. DOI:10.3390/v9040086.

5. WOAH. World Animal Health Information System. Available at: https://wahis.woah.org.

6. Malik Y. S., Bhat S., Kumar O. R. V., Yadav A. K., Sircar S., Ansari M. I., et al. Classical swine fever virus biology, clinicopathology, diagnosis, vaccines and a meta-analysis of prevalence: A review from the Indian perspective. Pathogens. 2020; 9 (6):500. DOI:10.3390/pathogens9060500.

7. Classical swine fever (infection with classical swine fever virus). In: WOAH. Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. 2022; Chapter 3.9.3. Available at: https://www.woah.org/fileadmin/Home/eng/Health_standards/tahm/3.09.03_CSF.pdf.

8. Suradhat S., Damrongwatanapokin S., Thanawongnuwech R. Factors critical for successful vaccination against classical swine fever in endemic areas. Vet. Microbiol. 2007; 119 (1): 1–9. DOI:10.1016/j.vetmic.2006.10.003.

9. Shevtsov А. А., Oganesyan A. S., Korennoy F. I., Scherbakov A. V., Karaulov A. K. Prognoz po klassicheskoj chume svinej na 2020 god = The forecast for classical swine fever for 2020. In: Forecasts for infectious animal diseases in the Russian Federation for 2020. Vladimir: FGBI “ARRIAH”; 2019; 81–112. (in Russ.).

10. Yagodinskiy V. N. Dynamics of the epidemic process. Moscow: Meditsina; 1977. 240 р. (in Russ.)

11. Isoda N., Baba K., Ito S., Ito M., Sakoda Y., Makita K. Dynamics of classical swine fever spread in wild boar in 2018–2019, Japan. Pathogens. 2020; 9 (2):119. DOI:10.3390/pathogens9020119.

12. Postel A., Nishi T., Kameyama K. I., Meyer D., Suckstorff O., Fukai K., Becher P. Reemergence of classical swine fever, Japan, 2018. Emerg. Infect. Dis. 2019; 25 (6): 1228–1231. doi:10.3201/eid2506.181578.

13. Choe S., Cha R. M., Yu D. S., Kim K. S., Song S., Choi S. H., et al. Rapid spread of classical swine fever virus among South Korean wild boars in areas near the border with North Korea. Pathogens. 2020; 9 (4):244. DOI:10.3390/pathogens9040244.

14. Pineda P., Deluque A., Peña M., Diaz O. L., Allepuz A., Casal J. Descriptive epidemiology of classical swine fever outbreaks in the period 2013–2018 in Colombia. PLoS One. 2020; 15 (6):e0234490. DOI:10.1371/journal.pone.0234490.

15. De Oliveira L. G., Gatto I. R. H., Mechler-Dreibi M. L., Almeida H. M. S., Sonálio K., Storino G. Y. Achievements and challenges of classical swine fever eradication in Brazil. Viruses. 2020; 12 (11):1327. DOI:10.3390/v12111327.

16. Meuwissen M. P., Horst S. H., Huirne R. B., Dijkhuizen A. A. A model to estimate the financial consequences of classical swine fever outbreaks: principles and outcomes. Prev. Vet. Med. 1999; 42 (3–4): 249–270. DOI:10.1016/s0167-5877(99)00079-3.

17. Luo Y., Li S., Sun Y., Qiu H. J. Classical swine fever in China: a mini­­review. Vet. Microbiol. 2014; 172 (1–2): 1–6. DOI:10.1016/j.vetmic.2014.04.004.

18. Luo T. R., Liao S. H., Wu X. S., Feng L., Yuan Z. X., Li H., et al. Phylogenetic analysis of the E2 gene of classical swine fever virus from the Guangxi Province of southern China. Virus Genes. 2011; 42 (3): 347–354. DOI:10.1007/s11262-011-0578-8.

19. Terebova S. V., Coltun G. G., Podvalova V. V., Korotkova I. P. Retrospective analysis of classical swine fever in wild boars in the Primorye. Dal’nevostochnyj agrarnyj vestnik = Far Eastern Agrarian Herald. 2019; 4 (52): 93–101. DOI:10.24411/1999-6837-2019-14059. (in Russ.)

20. Terebova S. V., Koltun G. G., Podvalova V. V., Zhivotovskiy V. A. Epizootic situation of classical swine fever in the primorskiy territory. Dal’nevostochnyj agrarnyj vestnik = Far Eastern Agrarian Herald. 2016; 3 (39): 77–82. eLIBRARY ID: 27216023. (in Russ.)

21. Terebova S. V., Koltun G. G., Podvalova V. V., Korotkova I. P. The efficiency of animal disease control for classical swine fever detection among wild boar on the territory of Ussuriisk urban district. Agrarian bulletin of Primorye. 2019; 2 (14): 20–23. eLIBRARY ID: 41297039. (in Russ.)

22. Wei Q., Liu Y., Zhang G. Research progress and challenges in vaccine development against classical swine fever virus. Viruses. 2021; 13 (3):445. DOI:10.3390/v13030445.

23. Ji W., Niu D. D., Si H. L., Ding N. Z., He C. Q. Vaccination influences the evolution of classical swine fever virus. Infect. Genet. Evol. 2014; 25: 69–77. DOI:10.1016/j.meegid.2014.04.008.

24. Shevtsov А. А., Dudnikov S. A., Karaulov A. K., Petrova O. N., Korennoy F. I., Vystavkina E. S. Some aspects of epizootic manifestations of classical and African swine fevers, Aujeski disease: an informational and analytical review. Vladimir: FGI “ARRIAH”; 2008. 38 p. (in Russ.)

25. Instruktsiya o meropriyatiyakh po preduprezhdeniyu i likvidatsii klassicheskoi chumy svinei = Instructions on measures taken to prevent and eliminate classical swine fever: approved. by GUV of the Ministry of Agriculture 30.03.1990. Available at: https://центр-ветеринарии.рф/images/docs/vetpravila/КЧС.pdf. (in Russ.)

26. Ganges L., Crooke H. R., Bohórquez J. A., Postel A., Sakoda Y., Becher P., Ruggli N. Classical swine fever virus: the past, present and future. Virus Res. 2020; 289:198151. DOI:10.1016/j.virusres.2020.198151.

27. Dahle J., Liess B. A review on classical swine fever infections in pigs: epizootiology, clinical disease and pathology. Comp. Immunol. Microbiol. Infect. Disease. 1992; 15 (3): 203–211. DOI:10.1016/0147-9571(92)90093-7.

28. Moennig V., Floegel-Niesmann G., Greiser-Wilke I. Clinical signs and epidemiology of classical swine fever: a review of new knowledge. Vet. J. 2003; 165 (1): 11–20. DOI:10.1016/s1090-0233(02)00112-0.

29. Elbers A. R., Vos J. H., Bouma A., Stegeman J. A. Ability of veterinary pathologiststo diagnose classicalswine fever from clinicalsigns and gross pathological findings. Prev. Vet. Med. 2004; 66 (1–4): 239–246. DOI:10.1016/j.prevetmed.2004.09.003.

30. Mittelholzer C., Moser C., Tratschin J. D., Hofmann M. A. Analysis of classical swine fever virus replication kinetics allows differentiation of highly virulent from avirulent strains. Vet. Microbiol. 2000; 74 (4): 293–308. DOI:10.1016/s0378-1135(00)00195-4.