Bang Jensen Britt, Nylund Stian, Svendsen Julie Christine, Ski Paul-Martin R, Takle Harald
Section for epidemiology, Norwegian Veterinary Institute, Oslo, Norway.
Pharmaq Analytiq AS, Bergen, Norway.
J Fish Dis. 2019 Jun;42(6):825-833. doi: 10.1111/jfd.12990. Epub 2019 Mar 28.
Losses due to cardiomyopathy syndrome (CMS) keep increasing in salmon-producing countries in the North-Atlantic. Recently, Piscine myocarditis virus (PMCV) has been detected in post-smolts shortly after sea-transfer, indicating a possible carry-over from the hatcheries. In addition, there are reports of prevalences of PMCV as high as 70%-90% in certain groups of broodfish, and a recent outbreak of CMS in the Faroe Islands has been linked to the importation of eggs from a CMS-endemic area. Thus, there is a need to investigate whether PMCV can be transmitted vertically from infected broodstock to their progeny. In the present study, samples from eggs, larvae, fingerlings and presmolt originating from PMCV-positive broodstock from two commercial Atlantic salmon producers were tested for PMCV. The prevalence of PMCV in the broodstock was 98% in the hearts, 69% in the roe and 59% in the milt. Piscine myocarditis virus was detected in all stages of the progeny until and including the 40 g stage. Piscine myocarditis virus was also detected in presmolt sampled for tissue tropism. This provides farmers with several options for minimizing the risk of transfer of PMCV from broodstock to progeny, including screening of broodstock and aiming to use only those that are negative for PMCV or have low levels of virus.
在北大西洋的鲑鱼生产国，由心肌病综合征（CMS）导致的损失持续增加。最近，在海水转移后不久的后幼鱼中检测到了鱼类心肌炎病毒（PMCV），这表明病毒可能是从孵化场携带而来。此外，有报道称某些亲鱼群体中PMCV的患病率高达70%-90%，法罗群岛最近爆发的CMS疫情与从CMS流行地区进口鱼卵有关。因此，有必要调查PMCV是否能从受感染的亲鱼垂直传播给它们的后代。在本研究中，对来自两家商业大西洋鲑鱼生产商的PMCV阳性亲鱼所产的鱼卵、幼体、鱼种和后幼鱼样本进行了PMCV检测。亲鱼心脏中PMCV的患病率为98%，鱼卵中为69%，精液中为59%。在后代的所有阶段直至包括40克阶段都检测到了鱼类心肌炎病毒。在为组织嗜性采样的后幼鱼中也检测到了鱼类心肌炎病毒。这为养殖户提供了几种将PMCV从亲鱼转移到后代的风险降至最低的选择，包括对亲鱼进行筛查，目标是只使用那些PMCV呈阴性或病毒水平低的亲鱼。
