Bouma A, De Jong M C, Kimman T G
DLO-Institute for Animal Science and Health, Lelystad, Netherlands.
Am J Vet Res. 1996 Jan;57(1):43-7.
To determine whether 2 pseudorabies virus (PRV) strains that differ in virulence differ in transmission among vaccine strain 783-inoculated pigs.
Three experiments were conducted, each with 2 groups of 10 pigs inoculated with the glycoprotein E-negative vaccine 783. In the first 2 experiments, half of one group was inoculated with the mildly virulent strain Sterksel, and half of the other group was inoculated with the virulent strain NIA-3. The remaining pigs were contact-exposed to the inoculated pigs. In the third experiment, 2 pigs in each group were inoculated with strain NIA-3, and the other 8 pigs in each group were contact-exposed to these 2 pigs.
Specific-pathogen-free pigs that were sero-negative for antibodies to PRV.
Estimation of the transmission of virus in each group was based on a stochastic model, in which the observable variable was the number of contact infections. The sole parameter of the model was the reproduction ratio theta. A glycoprotein E ELISA was used to determine whether infection occurred. Virus excretion in the oropharyngeal fluid was determined by plaque assay to measure infectivity.
Vaccinated pigs had a significant difference in virus excretion between the mildly virulent and virulent strains. Sterksel strain-inoculated pigs shed significantly more virus than did NIA-3 strain-inoculated pigs. Despite this difference in virus excretion, the 2 strains did not differ in transmission.
Both PRV strains would be eliminated from a population of vaccine strain 783-inoculated pigs.
确定两种毒力不同的伪狂犬病病毒（PRV）毒株在接种疫苗株783的猪之间的传播情况是否存在差异。
进行了三项实验，每项实验有两组，每组10头猪接种糖蛋白E阴性疫苗783。在前两项实验中，一组的一半接种弱毒株斯特克塞尔，另一组的一半接种强毒株NIA-3。其余的猪与接种的猪进行接触暴露。在第三项实验中，每组2头猪接种NIA-3毒株，每组的其他8头猪与这2头猪进行接触暴露。
对PRV抗体呈血清阴性的无特定病原体猪。
基于一个随机模型估计每组中病毒的传播情况，其中可观察变量是接触感染的数量。该模型的唯一参数是繁殖率θ。使用糖蛋白E ELISA来确定是否发生感染。通过蚀斑测定法测定口咽液中的病毒排泄量以测量感染性。
接种疫苗的猪在弱毒株和强毒株之间的病毒排泄量存在显著差异。接种斯特克塞尔毒株的猪排出的病毒明显多于接种NIA-3毒株的猪。尽管病毒排泄量存在这种差异，但这两种毒株在传播方面没有差异。
两种PRV毒株都将从接种疫苗株783的猪群中消除。
