Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr. NW, Calgary, Alberta T2N 4Z6, Canada.
Polar Knowledge Canada, Canadian High Arctic Research Station, 1 Uvajuq Rd., P.O. Box 2150, Cambridge Bay, Nunavut X0B 0C0, Canada.
J Wildl Dis. 2024 Apr 1;60(2):461-473. doi: 10.7589/JWD-D-22-00170.
Orf virus (genus Parapoxvirus) has been associated with gross skin lesions on muskoxen (Ovibos moschatus) from Victoria Island, Nunavut, Canada, where muskox populations are experiencing population declines. Orf virus causes painful proliferative and necrotizing dermatitis upon viral replication and shedding, which may lead to animal morbidity or mortality through secondary infections and starvation. Herpesvirus, known to cause gross lesions on skin and mucosa during active viral replication, has also been documented in muskoxen but to date has not been associated with clinical disease. Our objective was to characterize the variation of orf virus and herpesvirus in wild muskoxen of the Canadian Arctic. Tissue samples including gross skin lesions from the nose, lips, and/or legs were opportunistically collected from muskoxen on Victoria Island, Nunavut and Northwest Territories, and mainland Nunavut, Canada, from 2015 to 2017. Sampled muskoxen varied in age, sex, location, hunt type, and body condition. Tissues from 60 muskoxen were tested for genetic evidence of orf virus and herpesvirus infection using PCR targeting key viral genes. Tissues from 38 muskoxen, including 15 with gross lesions, were also examined for histological evidence of orf virus and herpesvirus infection. Eleven muskoxen (10 from Victoria Island and one from mainland Nunavut) with gross lesions had microscopic lesions consistent with orf virus infection. Muskox rhadinovirus 1, a gammaherpesvirus endemic to muskoxen, was detected in 33 (55%) muskoxen including 17 with gross lesions. In all tissues examined, there was no histological evidence of herpesvirus-specific disease. Sequencing and characterization of amplified PCR products using phylogenetic analysis indicated that a strain of orf virus, which appears to be unique, is likely to be endemic in muskoxen from Victoria Island and mainland Nunavut. Many of the muskoxen are also subclinically infected with a known muskox-endemic strain of herpesvirus.
口疮病毒（正痘病毒属）与加拿大努纳武特地区维多利亚岛的麝香牛（麝香牛属）的严重皮肤病变有关，那里的麝香牛种群正在减少。口疮病毒在病毒复制和脱落时会引起疼痛的增生性和坏死性皮炎，这可能会导致动物发病率或死亡率通过继发感染和饥饿。疱疹病毒，已知在病毒复制期间导致皮肤和粘膜出现严重病变，也在麝香牛中得到证实，但迄今为止与临床疾病无关。我们的目的是描述加拿大北极野生麝香牛中的口疮病毒和疱疹病毒的变异情况。2015 年至 2017 年，在加拿大努纳武特地区的维多利亚岛和西北地区以及努纳武特大陆上，从麝香牛身上偶然采集了包括鼻子、嘴唇和/或腿部的严重皮肤病变在内的组织样本。采样的麝香牛在年龄、性别、地点、狩猎类型和身体状况方面存在差异。用针对关键病毒基因的 PCR 检测 60 头麝香牛的组织中是否存在口疮病毒和疱疹病毒感染的遗传证据。从 38 头麝香牛的组织中检查了是否有口疮病毒和疱疹病毒感染的组织学证据，其中包括 15 头有严重病变的麝香牛。11 头（10 头来自维多利亚岛，1 头来自努纳武特大陆）有严重病变的麝香牛具有与口疮病毒感染一致的显微镜下病变。麝香牛疱疹病毒 1 是一种局限于麝香牛的γ疱疹病毒，在 33 头（55%）麝香牛中检测到，其中 17 头有严重病变。在所检查的所有组织中，均没有疱疹病毒特异性疾病的组织学证据。使用系统发育分析对扩增的 PCR 产物进行测序和特征描述表明，一种可能是特有的口疮病毒株在维多利亚岛和努纳武特大陆的麝香牛中可能是地方性的。许多麝香牛也感染了一种已知的麝香牛地方性疱疹病毒株。
