Molecular Epidemiology of Serotype O Foot-and-Mouth Disease Virus with Emphasis on West and South Africa

Abstract

Genetic relationships of serotype O foot-and-mouth disease (FMD) viruses recovered from outbreaks of the disease in the West African countries of Niger, Burkina Faso and, Ghana (1988–1993) and those from South Africa (2000) were determined by partial VP1 gene characterization. A 581-bp fragment, corresponding to the C-terminus half of the 1D (VP1 gene) region was amplified and sequenced. An homologous region of 495 nucleotides was ultimately used to determine genetic relationships of serotype O viruses from the Middle East, Europe, South America, North Africa, East Africa, southern Africa and Asia. Seven distinct type O genotypes were identified by phylogenetic reconstruction, consisting of viruses from the following geographical regions: Genotype A: Asia, the Middle East, and South Africa, Genotype B: East Africa, Genotype C: West and North Africa, Genotype D: Taiwan and Russia, Genotype E: Angola and Venezuela, Genotype F: Western Europe, and Genotype G: Europe and South America. The genotypes constitute three different evolutionary lineages (I–III), which correspond to three discrete continental regions, some of which display inter-continental distributions due to introductions. Results further indicate that the outbreaks in Burkina Faso (1992) and Ghana (1993) are part of the same epizootic and that the strain involved in a recent outbreak of the disease in South Africa is most closely related (97% sequence identity) to a 1997 Bangladesh strain.