A study of the biological properties of the exotic foot-and-mouth disease virus O/EA-3/Tunisia/2019 strain (lineage O/EA-3) isolated in North Africa

Introduction. Foot-and-mouth disease (FMD) outbreaks that were reported in Africa in 2013–2023 (Egypt – 2013–2017, 2021, Algeria – 2018, 2019, 2022, Senegal – 2018, Libya – 2019, 2023, Morocco – 2019, Tunisia – 2019, 2022), were caused by O/EA-3 topotype virus. Given the current epizootic situation in the region and the trade and economic ties between the Russian Federation and African countries, there is an urgent need to study foot-and-mouth disease virus (FMDV) O/EA-3 topotype strains to facilitate the development of diagnostic and specific prevention tools against this dangerous disease.

Objective. A study of the biological properties of the exotic FMDV O/EA-3/Tunisia/2019 strain (lineage O/EA-3) isolated in North Africa.

Materials and methods. FMDV O/EA-3/Tunisia/2019 strain was isolated from cattle in Tunisia in 2019. A combination of cultural, serological, and molecular genetic methods was applied during the study. 

Results. Based on comparative analysis of the nucleotide sequences, this strain was identified as belonging to the O/EA-3 genetic lineage. The antigenic relationship (r1 ) of the O/EA-3/Tunisia/2019 strain with FMDV production strains ranged from 0.01 to 0.54. The studied strain accumulated in cattle to an infectious titer of 5.00 log10 ID50 /0.1 mL, and in pigs to 4.75 log10 ID50 /0.1 mL. The FMDV O/EA-3/Tunisia/2019 antigen served as the basis for producing strain-specific rabbit sera for FMD diagnosis, as well as a culture-derived, inactivated, monovalent, adsorbed vaccine capable of providing protection against infection with this exotic FMDV strain.

Conclusion. Biological properties of the FMDV strain (O/EA-3 lineage) isolated in North Africa were studied. In light of the close antigenic relationship (r1 = 0.49) between the O/EA-3 and O/ME-SA/PanAsia2 genetic lineages, the production strain O 2356/Pakistan/2018, which belongs to the O/ME-SA/PanAsia2 lineage, may be used to protect animals against infection with FMDV of the O/EA-3 genetic lineage.

1. Arzt J., Sanderson M. W., Stenfeldt C. Foot-and-mouth disease. Veterinary Clinics of North America: Food Animal Practice. 2024; 40 (2): 191–203. https://doi.org/10.1016/j.cvfa.2024.01.001

2. Diaz-San Segundo F., Medina G. N., Stenfeldt C., Arzt J., de Los Santos T. Foot-and-mouth disease vaccines. Veterinary Microbiology. 2017; 206: 102–112. https://doi.org/10.1016/j.vetmic.2016.12.018

3. Foot and mouth disease (infection with foot and mouth disease virus). In: WOAH. Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. Chapter 3.1.8. https://www.woah.org/fileadmin/Home/fr/Health_standards/tahm/3.01.08_FMD.pdf

4. Bachanek-Bankowska K., Wadsworth J., Gray A., Abouchoaib N., King D. P., Knowles N. J. Genome sequence of foot-and-mouth disease virus serotype O isolated from Morocco in 2015. Genome Announcements. 2016; 4 (2):e01746-15. https://doi.org/10.1128/genomea.01746-15

5. Bouguedour R., Ripani A. Review of the foot and mouth disease situation in North Africa and the risk of introducing the disease into Europe. Revue Scientifique et Technique. 2016; 35 (3): 757–768. https://doi.org/10.20506/rst.35.3.2566

6. Canini L., Blaise-Boisseau S., Nardo A. D., Shaw A. E., Romey A., Relmy A., et al. Identification of diffusion routes of O/EA-3 topotype of foot-and-mouth disease virus in Africa and Western Asia between 1974 and 2019 – a phylogeographic analysis. Transboundary and Emerging Diseases. 2022; 69 (5): e2230-e2239. https://doi.org/10.1111/tbed.14562

7. Colenutt C., Brown E., Nelson N., Wadsworth J., Maud J., Adhikari B., et al. Environmental sampling as a low-technology method for surveillance of foot-and-mouth disease virus in an area of endemicity. Applied and Environmental Microbiology. 2018; 84 (16):e00686-18. https://doi.org/10.1128/aem.00686-18

8. Ellis J., Brown E., Colenutt C., Gubbins S. Assessing the effectiveness of environmental sampling for surveillance of foot-and-mouth disease virus in a cattle herd. Frontiers in Veterinary Science. 2023; 10:1074264. https://doi.org/10.3389/fvets.2023.1074264

9. González Gordon L., Porphyre T., Muhanguzi D., Muwonge A., Boden L., Bronsvoort B. M. C. A scoping review of foot-and-mouth disease risk, based on spatial and spatio-temporal analysis of outbreaks in endemic settings. Transboundary and Emerging Diseases. 2022; 69 (6): 3198–3215. https://doi.org/10.1111/tbed.14769

10. Howson E. L. A., Armson B., Lyons N. A., Chepkwony E., Kasanga C. J., Kandusi S., et al. Direct detection and characterization of foot-and-mouth disease virus in East Africa using a field-ready real-time PCR platform. Transboundary and Emerging Diseases. 2018; 65 (1): 221–231. https://doi.org/10.1111/tbed.12684

11. Kabelo T. I., Fana E. M., Hyera J. M., Lebani K. A review of foot-andmouth disease status and control measures in Botswana. Tropical Animal Health and Production. 2023; 55 (4):278. https://doi.org/10.1007/s11250-023-03674-5

12. Kardjadj M. History of foot-and-mouth disease in North African countries. Veterinaria Italiana. 2018; 54 (1): 1–12. https://doi.org/10.12834/vetit.928.4711.2

13. Paton D. J., Füssel A.-E., Vosloo W., Dekker A., De Clercq K. The use of serosurveys following emergency vaccination, to recover the status of “foot-and-mouth disease free where vaccination is not practised”. Vaccine. 2014; 32 (52):7050–7056. https://doi.org/10.1016/j.vaccine.2014.10.064

14. Zewdie G., Akalu M., Tolossa W., Belay H., Deresse G., Zekarias M., Tesfaye Y. A review of foot-and-mouth disease in Ethiopia: epidemiological aspects, economic implications, and control strategies. Virology Journal. 2023; 20 (1):299. https://doi.org/10.1186/s12985-023-02263-0

15. Shaw A. E., Lebani K., González Gordon L., Ihearahu U. E., Wadsworth J., Hicks H. M., et al. Universal amplification and sequencing of foot-and-mouth disease virus complete genomes using nanopore technology. BMC Genomics. 2025; 26 (1):770. https://doi.org/10.1186/s12864-025-11938-7

16. Singh I., Deb R., Kumar S., Singh R., Andonissamy J., Smita S., et al. Deciphering foot-and-mouth disease (FMD) virus-host tropism. Journal of Biomolecular Structure and Dynamics. 2019; 37 (18): 4779–4789. https://doi.org/10.1080/07391102.2019.1567386

17. Sobhy N. M., Bayoumi Y. H., Mor S. K., El-Zahar H. I., Goyal S. M. Outbreaks of foot and mouth disease in Egypt: molecular epidemiology, evolution and cardiac biomarkers prognostic significance. International Journal of Veterinary Science and Medicine. 2018; 6 (1): 22–30. https://doi.org/10.1016/j.ijvsm.2018.02.001

18. Squarzoni-Diaw C., Arsevska E., Kalthoum S., Hammami P., Cherni J., Daoudi A., et al. Using a participatory qualitative risk assessment to estimate the risk of introduction and spread of transboundary animal diseases in scarce-data environments: a spatial qualitative risk analysis applied to foot-and-mouth disease in Tunisia 2014–2019. Transboundary and Emerging Diseases. 2021; 68 (4): 1966–1978. https://doi.org/10.1111/tbed.13920

19. Ularamu H. G., Lefebvre D. J., Haegeman A., Wungak Y. S., Ehizibolo D. O., Lazarus D. D., et al. Complex circulation of foot-and-mouth disease virus in cattle in Nigeria. Frontiers in Veterinary Science. 2020; 7:466. https://doi.org/10.3389/fvets.2020.00466

20. Lozovoj D. A., Guseva M. N., Mikhalishin D. V., Doronin M. I., Manin B. L., Shishkova A. A., et al. BHK-21/SUSP/ARRIAH – continuous suspension subline of newborn syrian hamster kidney cells, intended for reproduction of foot-and-mouth disease viruses, rabies, parainfluenza-3, Aujeszky’s disease in producing antiviral vaccines, as well as for making diagnostic and preventive veterinary biopreparations. Patent No. 2722671 C1 Russian Federation, Int. C12N 5/10. Federal Centre for Animal Health. No. 2019131190. Date of filing: 01.10.2019. Date of publication: 02.06.2020. Bull. No. 16. (in Russ.)

21. Lugovskaya N. N., Kalinina Ye. N., Malkova K. S., Vorobyova O. V., Goryacheva G. M., Mayorova T. K. Validation of the technique aimed at the determination of FMD antibodies in liquid phase blocking sandwich ELISA. Veterinary Science Today. 2015; (3): 22–29. https://veterinary.arriah.ru/jour/article/view/203 (in Russ.)

22. OIE Quality Standard and Guidelines for Veterinary Laboratories: Infectious Diseases, 2nd ed. Paris, 2008. 70 p.

23. Stumpf M. P. H. Biology challenging statistics. Statistical Applications in Genetics and Molecular Biology. 2018; 17 (4):20180048. https://doi.org/10.1515/sagmb-2018-0048

24. Viari A. Big data in biology. Médecine Sciences. 2012; 28 (12): 1027-1028. https://doi.org/10.1051/medsci/20122812001 (in French)