Shedding patterns in swine of virulent and attenuated pseudorabies virus
Maes, R.K.; Kanitz, C.L.; Gustafson, D.P.
American Journal of Veterinary Research 44(11): 2083-2086
1983
ISSN/ISBN: 0002-9645 PMID: 6316822 Document Number: 209575
Shedding patterns of 2 virulent (P-2208 and KC-152-D) and 1 attenuated (BUK) strains of pseudorabies virus (PRV) were determined in groups of intranasally inoculated feeder pigs. Clinical signs observed following inoculation with the P-2208 and KC-152-D stains included increase in rectal temperatures up to 42.2.degree. C, anorexia, severe respiratory disturbance and fatal CNS signs in 2 cases. Clinical signs in pigs inoculated with 7.2 .times. 107 median tissue culture infective dose (TCID50) of the BUK strain were limited to depression and a rise in rectal temperatures to 40.5 C for 3-4 days. Evaluation of the efficacy of the virus isolation method used showed that the presence on swabs of only 12.5 TCID50 of the P-2208 strain or 8.4 TCID50 fo the BUK strain resulted in a 50% chance of virus recovery. Intranasal inoculations with 500 TCID50 of the P-2208 or KC-152-D strain did not result in synchronous infection of the whole group. Intranasal inoculations with 5000 TCID50 of the KC-152-D strain or 50,000 TCID50 of the P-2208 strain resulted in continuous virus shedding in all pigs between postinoculation days (PID) 4 and 13 (KC-152-D strain) or 14 (P-2208 strain). Some of the pigs in these 2 groups further shed the P-2208 or KC-152-D strain in a continuous or discontinuous pattern up to PID 19 (P-2208 strain) or 20 (KC-152-D strain). The time of onset or the level of virus neutralizing antibody production in individual pigs was not found to have an influence on their shedding patterns. Three of 4 pigs inoculated intranasally with 106 TCID50 of the P-2208 strain were still shedding PRV on the 22nd day after inoculation. Pigs inoculated intranasally with 500 or 5000 TCID50 of the attenuated BUK strain did not shed detectable amounts of virus. Shedding of this strain by 4 pigs inoculated intranasally with 7.2 .times. 107 TCID50 was detected between PID 3 and 7.