Detection of foot-and-mouth disease virus infection in cattle and pigs at Mannuthy, Kerala

The important reason for investigating an outbreak is to identify the source of ongoing outbreaks and prevent subsequent cases thereby controlling the disease. The present study highlighting the investigation of foot-and-mouth disease (FMD) outbreak in organized cattle and pig farm at Mannuthy, Kerala was done between January and March 2013. A total of 14 serum samples from cattle, 30 serum samples from pigs along with 7 snout epithelial samples from pigs were collected. In 3AB non-structural protein (NSP) ELISA, 92.85% cattle and 43.33% pig sera were found positive indicating high to moderate virus activity in the animals. All serum samples were also subjected to liquid phase blocking (LPB) ELISA to assess the level of protective antibody titre against FMD virus (FMDV) serotypes O, A and Asia 1, where 64.28% cattle and 23.33% pigs were found to have protective log10 antibody titre of >1.8 against all three serotypes. This indicates poor herd immunity against FMDV in pigs and moderate in case of cattle. Further, 4 snout epithelial samples from pigs were found to be positive for serotype O in serotype differentiating antigen detection ELISA and 3 were subsequently found positive in multiplex PCR. In VP1 region based phylogenetic analysis, the serotype O isolates clustered within ‘Ind2001’ lineage. Poor level of herd immunity might have been one of the contributing factors behind the outbreak in the farm.