The role of African buffalo in the epidemiology of foot-and-mouth disease in sympatric cattle and buffalo populations in Kenya

Authors: OMONDI, GEORGE - University Of Minnesota; GAKUYA, FRANCIS - Kenya Wildlife Service; Arzt, Jonathan; SANGULA, ABRAHAM - Ministry Of Agriculture, Livestock And Fisheries, State Department Of Livestock; Hartwig, Ethan; Pauszek, Steven; Smoliga, George; BRITO, BARBARA - Orise Fellow; PEREZ, ANDRES - University Of Minnesota; OBANDA, VINCENT - Kenya Wildlife Service; VANDERWAAL, KIMBERLY - University Of Minnesota

Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2020
Publication Date: 4/17/2020
Citation: Omondi, G., Gakuya, F., Arzt, J., Sangula, A., Hartwig, E.J., Pauszek, S.J., Smoliga, G.R., Brito, B.P., Perez, A., Obanda, V., Vanderwaal, K. 2020. The role of African buffalo in the epidemiology of foot-and-mouth disease in sympatric cattle and buffalo populations in Kenya. Transboundary and Emerging Diseases. https://doi.org/10.1111/tbed.13573.
DOI: https://doi.org/10.1111/tbed.13573

Interpretive Summary: Foot-and-mouth disease (FMD) is an important infectious disease that limits global trade in animal products. FMD has not occurred in the USA since 1929, but it remains a serious threat. To better understand how FMD virus (FMDV) moves between livestock and wildlife, we undertook a study of the transmission of the virus between buffalo and cattle under natural conditions in Kenya. Eighty distinct strains of FMDV were recovered from buffalo, which is more than have ever been reported; additionally, 6 buffalo were found to be simultaneously infected with 2 distinct strains. By contrast only few viruses were recovered from cattle in the same region and the strains were quite different from those recovered from the buffalo. Overall, the study concludes that transmission between cattle and buffalo is rare in Kenya. This information would be highly relevant if an outbreak ever occurred in the USA.

Technical Abstract: Transmission of pathogens at wildlife-livestock interfaces poses a substantial challenge to the control of infectious diseases, including for foot-and-mouth disease virus (FMDV) in African buffalo and cattle. The extent to which buffalo play a role in the epidemiology of this virus in livestock populations remains unresolved in East Africa. Here, we show that FMDV occurs at high seroprevalence (~77%) in Kenyan buffalo. In addition, we recovered 80 FMDV VP1 sequences from buffalo, all of which were serotype SAT1 and SAT2, and seventeen FMDV VP1 sequences from cattle, which included serotypes A, O, SAT1 and SAT2. Notably, six individual buffalo were co-infected with both SAT1 and SAT2 serotypes. Our results suggest that transmission of FMDV between sympatric cattle and buffalo is rare. However, viruses from FMDV outbreaks in cattle elsewhere in Kenya were caused by viruses closely related to SAT1 and SAT2 viruses found in buffalo. We also show that the circulation of FMDV in buffalo is influenced by fine-scale geographic features, such as rivers, and that social segregation amongst sympatric herds may limit between-herd transmission. Our results significantly advance knowledge of the ecology and molecular epidemiology of FMDV at wildlife-livestock interfaces in Eastern Africa, and will help to inform the design of control and surveillance strategies for this disease in the region.