Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany.
Zoonoses Public Health. 2012 Sep;59 Suppl 2:95-101. doi: 10.1111/zph.12015.
West Nile virus (WNV) is a flavivirus that is maintained in an enzootic cycle between ornithophilic mosquitoes, mainly of the Culex genus, and certain wild bird species. Other bird species like ravens, jays and raptors are highly susceptible to the infection and may develop deadly encephalitis, while further species of birds are only going through subclinical infection. The objective of this study was to continue in years 2009-2011 the serological and molecular surveillance in wild birds in Germany (see Vector Borne Zoonotic Dis. 10, 639) and to expand these investigations for the first time also to sera from domestic poultry and horses collected between 2005 and 2009. All three cohorts function as indicators for the endemic circulation of WNV. The presence of WNV-specific antibodies was detected in all samples by virus neutralization test (VNT), indirect immunofluorescence test (IFT) and/or enzyme-linked immunosorbent assay (ELISA). The presence of WNV genomes was monitored in relevant sera using two qRT-PCRs that amplify lineage 1 and 2 strains. A total of 364 migratory and resident wild bird serum samples (with emphasis on Passeriformes and Falconiformes) as well as 1119 serum samples from domestic poultry and 1282 sera from horses were analysed. With the exception of one hooded crow, antibody carriers were exclusively found in migratory birds, but not in resident birds/domestic poultry or in local horses. Crows are facultative, short-distance winter migrants in Germany. WNV-specific nucleic acids could not be demonstrated in any of the samples. According to these data, there is no convincing evidence for indigenous WNV infections in equines and in wild/domestic birds in Germany. However, since a few years, WNV infections are endemic in other European countries such as Austria, Hungary, Greece and Italy, a state-of-the-art surveillance system for the detection of incursions of WNV into Germany deems mandatory.
西尼罗河病毒（WNV）是一种黄病毒，在以库蚊属（Culex）等嗜鸟性蚊子与某些野生鸟类之间维持着地方性循环。其他鸟类，如乌鸦、松鸦和猛禽，极易感染该病毒，可能会发展为致命的脑炎，而其他鸟类种属仅经历亚临床感染。本研究的目的是在 2009-2011 年继续对德国野生鸟类进行血清学和分子监测（见 Vector Borne Zoonotic Dis. 10, 639），并首次将这些调查扩展到 2005-2009 年采集的家禽和马的血清。这三组样本都作为西尼罗河病毒地方性循环的指示物。通过病毒中和试验（VNT）、间接免疫荧光试验（IFT）和/或酶联免疫吸附试验（ELISA）检测所有样本中是否存在西尼罗河病毒特异性抗体。使用两种分别扩增谱系 1 和 2 株的 qRT-PCR 监测相关血清中是否存在西尼罗河病毒基因组。共分析了 364 份迁徙和留鸟的野生鸟类血清样本（重点是雀形目和隼形目）以及 1119 份家禽血清样本和 1282 份马血清样本。除了一只戴帽的乌鸦外，抗体携带者仅在迁徙鸟类中发现，而在留鸟/家禽或当地马匹中未发现。乌鸦在德国是一种兼性、短距离冬季候鸟。在任何样本中均未检测到西尼罗河病毒特异性核酸。根据这些数据，没有令人信服的证据表明德国的马和野生/家禽鸟类存在本土西尼罗河病毒感染。然而，由于近年来，西尼罗河病毒感染在奥地利、匈牙利、希腊和意大利等其他欧洲国家呈地方性流行，因此，建立先进的监测系统以检测西尼罗河病毒传入德国是强制性的。
