Arch Virol (2006) 151: 285–298
Retrospective genetic analysis of SAT-1 type foot-and-mouth
disease outbreaks in southern Africa
, A. D. S. Bastos
, and C. I. Boshoff
Exotic Diseases Division, Onderstepoort Veterinary Institute,
Onderstepoort, South Africa
Department of Tropical Veterinary Diseases, University of Pretoria,
Pretoria, South Africa
Mammal Research Institute, Department of Zoology and Entomology,
University of Pretoria, Pretoria, South Africa
Avimmune, Lyttelton, South Africa
Received March 15, 2005; accepted July 22, 2005
Published online September 9, 2005
Summary. In areas where foot-and-mouth disease (FMD) is endemic in wildlife
hosts, such as the Kruger National Park (KNP) in South Africa, control measures
are in place that ensure that potentially infected antelope and buffalo do not come
into close contact with domestic animals. In South Africa several SAT-1 out-
breaks occurred nearly simultaneously in cattle and impala between 1971–1981.
Phylogenetic analysis based on partial 1D gene nucleotide sequencing indicated
that several of these outbreaks were linked and it is probable that disease spread
from the intermediary impala antelope host to cattle in close proximity.
Evidence was found for the involvement of viruses from a single KNP genotype
in precipitating outbreaks in impala over a 10-year period. In addition, several
unrelated outbreaks affecting cattle and impala occurred within a single year.
Characterisation of outbreak strains from Botswana similarly revealed that a single
genotype affected different species over a 10-year period and that transboundary
spread of SAT-1 virus occurred on at least one occasion. This retrospective analysis
of outbreak strains has clearly demonstrated that FMD control policies that address
the role of antelope as intermediaries in disease transmission are crucial as these
wildlife species play an important role in disease dissemination.
Foot-and-mouth disease (FMD) is a vesicular disease that affects over 70 cloven-
hoofed species . Although it depresses productivity in high producing farming
systems and has a high morbidity, the mortality in adult animals is normally low.