Hershberger P K, Gregg J L, Grady C A, Collins R M, Winton J R
U.S. Geological Survey, Western Fisheries Research Center, Marrowstone Marine Field Station, 616 Marrowstone Point Road, Nordland, Washington 98358, USA.
J Aquat Anim Health. 2010 Mar;22(1):1-7. doi: 10.1577/H09-026.1.
Laboratory challenges using specific-pathogen-free Pacific herring Clupea pallasii from three distinct populations indicated that stock origin had no effect on susceptibility to viral hemorrhagic septicemia (VHS). All of the populations were highly susceptible to the disease upon initial exposure, with significantly greater cumulative mortalities occurring in the exposed treatment groups (56.3-64.3%) than in the unexposed control groups (0.8-9.0%). Interstock differences in cumulative mortality were not significant. The virus loads in the tissues of fish experiencing mortality were 10-10,000 times higher during the acute phase of the epizootics (day 13 postexposure) than during the recovery phase (days 30-42). Survivors of the epizootics were refractory to subsequent VHS, with reexposure of VHS survivors resulting in significantly less cumulative mortality (1.2-4.0%) than among positive controls (38.1-64.4%); interstock differences in susceptibility did not occur after reexposure. These results indicate that data from experiments designed to understand the ecology of VHS virus in a given stock of Pacific herring are broadly applicable to stocks throughout the northeastern Pacific.
利用来自三个不同种群的无特定病原体的太平洋鲱（Clupea pallasii）进行的实验室挑战表明，种群来源对病毒性出血性败血症（VHS）的易感性没有影响。所有种群在初次接触时对该病都高度易感，暴露处理组的累积死亡率（56.3 - 64.3%）显著高于未暴露对照组（0.8 - 9.0%）。累积死亡率的种群间差异不显著。在疫病流行的急性期（暴露后第13天），死亡鱼组织中的病毒载量比恢复期（第30 - 42天）高10 - 10000倍。疫病流行的幸存者对随后的VHS具有抗性，再次暴露于VHS的幸存者的累积死亡率（1.2 - 4.0%）显著低于阳性对照组（38.1 - 64.4%）；再次暴露后易感性不存在种群间差异。这些结果表明，旨在了解特定太平洋鲱种群中VHS病毒生态学的实验数据广泛适用于整个东北太平洋的种群。
