Retrospective diagnosis of foot and mouth disease outbreaks by liquid phase blocking enzyme linked immunosorbent assay.

A total of 82 serum samples from 30 foot and mouth disease (FMD) outbreaks occurring in Haryana between January 2002 and December 2003 were analyzed retrospectively for antibody titres using liquid phase blocking enzyme linked immunosorbent assay (LPB-ELISA) against FMD virus serotypes 0, A and Asia\. These outbreaks were retrospectively diagnosed and causative agent categorized as belonging to FMD virus serotype °(13), A (10) and Asia 1 (I), while in six outbreaks no conclusive FMD virus serotype could be established. Further, of these 30 outbreaks, clinical samples of tongue epithelium were also available for FMD virus serotyping from 12 outbreaks and involved FMD virus serotypes °(10) and A (2) as analyzed by sandwich ELISA. The findings of the retrospective studies on 34 serum samples from these 12 outbreaks using LPB-ELISA corroborated well with the FMD virus serotyping results using sandwich ELISA: Thus LPB-ELISA can be used as a test for establishing the retrospective diagnosis ofFMD virus serotype involved in a particular outbreak where suitable clinical sample(s) are not available.