Serotype identification and VP1 coding sequence analysis of foot-and-mouth disease viruses from outbreaks in eastern and northern Uganda in 2008/9.

In April 2008, foot-and-mouth disease (FMD) outbreaks were reported in Kamuli district of the eastern region of Uganda. Soon after lifting the quarantines in this area, further FMD outbreaks were reported in northern Uganda, which spread to more than 10 districts. The aim of this study was to identify the serotype and compare the variable protein (VP)1 coding sequences of the viruses responsible for FMD outbreaks during 2008 and 2009, to trace the transmission pathways of the disease in Uganda. Probang and epithelial swab samples were collected from cattle with clinical signs of FMD in the two regions, and the presence of FMDV RNA in these samples was determined using a standard diagnostic RT-PCR assay. From the total of 27 positive samples, the VP1 coding region was amplified and sequenced. Each of these sequences showed >99% identity to each other, and just five distinct sequences were identified. BLAST searches and phylogenetic analysis of the complete variable protein (VP)1 coding sequences revealed that they belonged to serotype O, topotype EA-2. The close similarity between the virus sequences suggested introduction from a single source. We therefore conclude that FMD in the northern region of Uganda was most likely introduced from the outbreak in the eastern region across Lake Kyoga through movement of live animals. This has significant implications for the effectiveness of the current FMD control measures.