A note on outbreaks caused by mixed foot-and-mouth disease virus infections.

Two outbreaks of foot-and-mouth disease (FMD) in vaccinated cattle were investigated wherein a mixed infection due to FMD virus (FMDV) types O and Asia 1 was detected by sandwich enzyme-linked immunosorbent assay (ELISA) and confirmed by antigen capture polymerase chain reaction (PCR). The clinical picture and the epidemiological data on these outbreaks are presented. The isolated virus strains were compared to the respective vaccine strains by means of monoclonal antibody (MAb) profiling and nucleotide sequence analysis. The probable cause of the mixed FMDV infection and its significance in disease control are discussed.