Nemeth Nicole, Gould Daniel, Bowen Richard, Komar Nicholas
Centers for Disease Control and Prevention, Fort Collins, Colorado 80522, USA.
J Wildl Dis. 2006 Jan;42(1):1-13. doi: 10.7589/0090-3558-42.1.1.
We studied the effects of natural and/or experimental infections of West Nile virus (WNV) in five raptor species from July 2002 to March 2004, including American kestrels (Falco sparverius), golden eagles (Aquila chrysaetos), red-tailed hawks (Buteo jamaicensis), barn owls (Tyto alba), and great horned owls (Bubo virginianus). Birds were infected per mosquito bite, per os, or percutaneously by needle. Many experimentally infected birds developed mosquito-infectious levels of viremia (>10(5) WNV plaque forming units per ml serum) within 5 days postinoculation (DPI), and/ or shed virus per os or per cloaca. Infection of organs 15-27 days postinoculation was infrequently detected by virus isolation from spleen, kidney, skin, heart, brain, and eye in convalescent birds. Histopathologic findings varied among species and by method of infection. The most common histopathologic lesions were subacute myocarditis and encephalitis. Several birds had a more acute, severe disease condition represented by arteritis and associated with tissue degeneration and necrosis. This study demonstrates that raptor species vary in their response to WNV infection and that several modes of exposure (e.g., oral) may result in infection. Wildlife managers should recognize that, although many WNV infections are sublethal to raptors, subacute lesions could potentially reduce viability of populations. We recommend that raptor handlers consider raptors as a potential source of WNV contamination due to oral and cloacal shedding.
2002年7月至2004年3月，我们研究了西尼罗河病毒（WNV）自然感染和/或实验性感染对五种猛禽的影响，这五种猛禽包括美洲隼（Falco sparverius）、金雕（Aquila chrysaetos）、红尾鵟（Buteo jamaicensis）、仓鸮（Tyto alba）和大角鸮（Bubo virginianus）。通过蚊虫叮咬、经口或经皮注射针头使鸟类感染病毒。许多经实验感染的鸟类在接种后5天内（DPI）出现了蚊虫可感染水平的病毒血症（每毫升血清中WNV空斑形成单位>10⁵），和/或经口或经泄殖腔排出病毒。在恢复期鸟类中，接种后15 - 27天从脾脏、肾脏、皮肤、心脏、大脑和眼睛中分离病毒，很少检测到器官感染。组织病理学发现因物种和感染方法而异。最常见的组织病理学病变是亚急性心肌炎和脑炎。几只鸟出现了以动脉炎为特征的更急性、严重的疾病状况，并伴有组织变性和坏死。本研究表明，猛禽物种对WNV感染的反应各不相同，并且几种暴露方式（例如经口）可能导致感染。野生动物管理者应认识到，尽管许多WNV感染对猛禽是亚致死性的，但亚急性病变可能会降低种群的生存能力。我们建议猛禽饲养者将猛禽视为WNV污染的潜在来源，因为它们会经口和泄殖腔排出病毒。
