Contact transmission of vesicular stomatitis virus New Jersey in pigs

Objective-To determine how viral shedding and development or lack of clinic al disease relate to contact transmission of vesicular stomatitis virus New jersey (VSV-NJ) in pigs and determine whether pigs infected by contact cou ld infect other pigs by contact. Animals-63 pigs Procedure-Serologically naive pigs were housed in direct contact with pigs that were experimentally inoculated with VSV-NJ via ID inoculation of the a pex of the snout, application to a scarified area of the oral mucosa, appli cation to intact oral mucosa, or ID inoculation of the ear. In a second exp eriment, pigs infected with VSV-NJ by contact were moved and housed with ad ditional naive pigs. Pigs were monitored and sampled daily for clinical dis ease and virus isolation and were serologically tested before and after inf ection or contact. Results-Contact transmission developed only when vesicular lesions were evi dent. Transmission developed rapidly; contact pigs shed virus as early as 1 day after contact. in pens in which contact transmission was detected, 2 o f 3 or 3 of 3 contact pigs were infected. Conclusions and Clinical Relevance-Transmission was lesion-dependent; howev er, vesicular lesions often were subtle with few or no clinical signs of in fection. Contact transmission was efficient, with resulting infections rang ing from subclinical (detected only by seroconversion) to clinical (develop ment of vesicular lesions). Long-term maintenance of VSV-NJ via contact tra nsmission alone appears unlikely. Pigs represent an efficient large-animal system for further study of VSV-NJ pathogenesis and transmission.