Institute of Marine Research, P.O. Box 1870 Nordnes, 5817 Bergen, Norway.
National Institute of Aquatic Resources, Section for Fish and Crustacean Diseases, Technical University of Denmark, 2800 Lyngby, Denmark.
Viruses. 2023 Jan 4;15(1):152. doi: 10.3390/v15010152.
Viral hemorrhagic septicaemia virus (VHSV) has been demonstrated to cause high mortalities in a wide range of teleosts, farmed as well as wild. In Europe, VHSV of genotypes Ib, Id, II, and III have been detected in wild fish, including Atlantic herring , but disease outbreaks have not been observed in Atlantic herring and the effects on wild stocks are not well documented. Here, we have tested two VHSV isolates from herring (genotypes Ib and III, from the western coasts of Norway and Denmark, respectively) in a challenge experiment with herring (mean weight 2.59 g, SD 0.71 g) caught on the west coast of Denmark. The Norwegian genotype Ib isolate (NO-F-CH/2009) showed an accumulated mortality of 47% compared to 6% mortality with the Danish genotype III isolate 4p168 and zero in the unchallenged control group. In both groups, we found positive rt-RT-PCR and positive immunohistochemistry of VHSV from days 6 and 8 onward. With both isolates, the organs mainly affected were the heart and kidney. The results demonstrate the susceptibility of Atlantic herring to VHSV, and both genotypes gave pathological findings in several organs. Genotype III showed a low mortality rate, and the importance of this genotype for herring is therefore not determined. Genotype Ib showed both high prevalence and mortality, and this genotype is therefore likely to have a negative effect on wild Atlantic herring stocks. Further examinations to determine how VHSV can affect wild Atlantic herring stocks are needed.
病毒性出血性败血症病毒 (VHSV) 已被证明会导致广泛的硬骨鱼类（包括养殖和野生鱼类）高死亡率。在欧洲，已在野生鱼类中检测到基因型 Ib、Id、II 和 III 的 VHSV，包括大西洋鲱鱼，但在大西洋鲱鱼中未观察到疾病爆发，并且对野生种群的影响也没有得到很好的记录。在这里，我们使用来自挪威和丹麦西海岸的鲱鱼（基因型 Ib 和 III，分别来自挪威和丹麦西海岸）中的两种 VHSV 分离株进行了挑战实验，实验鲱鱼的平均体重为 2.59 克，标准差为 0.71 克。来自挪威的基因型 Ib 分离株（NO-F-CH/2009）的累积死亡率为 47%，而来自丹麦的基因型 III 分离株 4p168 的死亡率为 6%，未受挑战的对照组为 0。在这两个组中，我们都发现了阳性 rt-RT-PCR 和 VHSV 的阳性免疫组织化学，从第 6 天和第 8 天开始。两种分离株都主要影响心脏和肾脏。结果表明大西洋鲱鱼对 VHSV 的易感性，两种基因型都在几个器官中引起了病理变化。基因型 III 的死亡率较低，因此这种基因型对鲱鱼的重要性尚未确定。基因型 Ib 显示出高流行率和高死亡率，因此可能对野生大西洋鲱鱼种群产生负面影响。需要进一步研究以确定 VHSV 如何影响野生大西洋鲱鱼种群。
