ANALYSIS OF SITES OF FOOT-AND-MOUTH-DISEASE VIRUS PERSISTENCE IN CARRIER CATTLE VIA THE POLYMERASE CHAIN-REACTION

This study was undertaken in order to explore possible sites of foot-a nd-mouth disease virus (FMDV) persistence during the carrier state. Ti ssue samples taken from experimentally infected animals at different t imes post-infection (p.i) were examined by conventional viral isolatio n and the polymerase chain reaction (PCR) technique. The analysis of s amples from several organs taken from 17 bovines between 3 and 270 day s p.i. allowed the following conclusions: 1) Virus present in oesophag eal-pharyngeal fluids (OFF) during the carrier state originates in the pharynx as shown by the detection of antisense FMDV RNA by PCR, 2) PC R is more sensitive than standard virus isolation techniques and may b e used for the rapid detection of FMDV in specimens obtained during th e acute stage of FMD and for identification of persistently infected c attle.