IMPROVED DETECTION OF PERSISTENT FOOT-AND-MOUTH-DISEASE INFECTION IN CATTLE BY THE POLYMERASE CHAIN-REACTION

Persistent foot-and-mouth disease (FMD) infection of cattle was establ ished by exposure to infected pigs. Oesophageal-pharyngeal fluid sampl es collected ante-mortem and tissue samples obtained post-mortem were tested for virus by conventional means and for viral RNA by the polyme rase chain reaction (PCR). The results showed that the PCR was superio r for detecting the carrier state in tissue samples. A high neutralisi ng activity in tissues probably influenced the yields of virus obtaine d by infectivity assay.