Spatial Trend of Foot and Mouth Disease Virus （FMDV） Serotypes in Cattle and Buffaloes, Pakistan

The present study describes the frequency of Foot and Mouth Disease （FMD） virus serotypes （O, A and Asia-l） in major regions （all provinces） of Pakistan using Indirect Sandwich ELISA. Also, spatial distribution of various FMD serotypes and their comparison is discussed. A total of 590 samples （Epithelial tissue） have been analyzed during a period of five years （2005-2009）. Out of 590 samples, 180 were found positive, giving an overall confirmation of FMDV about 33.2 %. Of the prevalent serotypes, FMDV ＇O＇ serotype caused most outbreaks （20.7 %）, followed by serotype A （6.6 %） and serotype Asia-1 （4.6 %） while there was no positive case of type ＇C＇. The study clearly showed that the disease was more frequent in the agro-climatic zones than in hilly areas. Based on the data of 590 samples （〉50 outbreaks）, the overall prevalence of FMDV in cattle and buffaloes in Pakistan was 33.2 %, while in cattle alone, it was 37.1%, higher than in buffalo （28.7 %）. There were eight cases of mixed serotypes infection, indicating the presence of endemic state of disease. Another significant feature was the change over time. In phase-I （2005-2007）, there was an overall prevalence of 29.4 %, while the occurrence of the serotype O, A and Asia-1 was 20.4 %, 2.9 % and 4.7 %, respectively. During phase-II （2008-2009）, the overall prevalence was 59.21%, while those of serotype O, A and Asia-1 were 22.4 %, 31.6 % and 4.0 %, respectively. This clearly indicated a shift from serotype O to A, which may help to explain the occurrence of more severe outbreaks, despite vaccination.