Joyner Priscilla H, Kelly Sean, Shreve Allison A, Snead Sarah E, Sleeman Jonathan M, Pettit Denise A
The Wildlife Center of Virginia, PO Box 1557, Waynesboro, Virginia 22980, USA.
J Wildl Dis. 2006 Apr;42(2):335-44. doi: 10.7589/0090-3558-42.2.335.
Sixty-one birds of prey admitted to The Wildlife Center of Virginia (WCV; Waynesboro, Virginia, USA) from June to November 2003 were tested for West Nile virus (WNV) infection. Choanal and/or cloacal swabs were obtained and submitted to Virginia's Division of Consolidated Laboratory Services (Richmond, Virginia, USA) for analysis with real-time reverse transcriptase polymerase chain reaction (RT-PCR). Forty birds of prey were positive for WNV by RT-PCR. Five avian families and nine species of raptors were represented, with great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) most frequently affected. Presenting clinical signs were consistent with previous reports of WNV infection in raptors; however, these differed between species. Of WNV positive birds, nonspecific signs of illness were the most common clinical findings, particularly in red-tailed hawks; signs included dehydration (n = 20), emaciation (n = 18), and depression (n = 15). Neurologic abnormalities were frequently identified, especially in great horned owls, and included head tremors (n = 17), ataxia (n = 13), head incoordination (n = 7), torticollis (n = 3), nystagmus (n = 3), and head tilt (n = 3). Great horned owls exhibited anemia and leukocytosis with heterophilia, eosinophilia, and monocytosis consistent with chronic inflammation. Red-tailed hawks were anemic with a heterophilic leukocytosis and regenerative left shift. The majority of WNV cases occurred during August and September; there was a marked increase in the number of raptors admitted to WCV during these months followed by a marked decrease during October, November, and December. This pattern differed from mean monthly admissions during the previous 10 years and suggests a negative impact on local raptor populations. The effects of WNV on avian populations are largely unknown; however, because of their ecological importance, further investigation of the effects of WNV on raptor populations is warranted.
2003年6月至11月间，弗吉尼亚野生动物中心（美国弗吉尼亚州韦恩斯伯勒市的WCV）接收的61只猛禽接受了西尼罗河病毒（WNV）感染检测。采集了后鼻孔和/或泄殖腔拭子，并提交给弗吉尼亚综合实验室服务部（美国弗吉尼亚州里士满），用实时逆转录聚合酶链反应（RT-PCR）进行分析。40只猛禽经RT-PCR检测WNV呈阳性。涉及5个鸟类科和9种猛禽，其中大角鸮（Bubo virginianus）和赤尾鹰（Buteo jamaicensis）受影响最为频繁。呈现的临床症状与先前关于猛禽WNV感染的报道一致；然而，这些症状在不同物种之间有所不同。在WNV呈阳性的鸟类中，非特异性疾病症状是最常见的临床发现，尤其是在赤尾鹰中；症状包括脱水（n = 20）、消瘦（n = 18）和抑郁（n = 15）。神经系统异常经常被发现，特别是在大角鸮中，包括头部震颤（n = 17）、共济失调（n = 13）、头部不协调（n = 7）、斜颈（n = 3）、眼球震颤（n = 3）和头部倾斜（n = 3）。大角鸮表现出贫血和白细胞增多，伴有嗜异性粒细胞增多、嗜酸性粒细胞增多和单核细胞增多，与慢性炎症一致。赤尾鹰贫血，伴有嗜异性粒细胞性白细胞增多和再生性左移。大多数WNV病例发生在8月和9月；这几个月WCV接收的猛禽数量显著增加，随后在10月、11月和12月显著减少。这种模式与前10年的月平均接收量不同，表明对当地猛禽种群有负面影响。WNV对鸟类种群的影响在很大程度上尚不清楚；然而，由于它们的生态重要性，有必要进一步研究WNV对猛禽种群的影响。
