Centro de Investigación en Sanidad Animal (CISA)-INIA, Ctra. Algete-El Casar s/n, 28130 Valdeolmos, Spain.
Estación Biológica de Doñana-CSIC, Seville, Spain.
Vet Microbiol. 2014 Aug 27;172(3-4):542-7. doi: 10.1016/j.vetmic.2014.06.005. Epub 2014 Jun 10.
West Nile virus (WNV) is a zoonotic pathogen which is maintained in an enzootic cycle between mosquitoes and birds; humans, equines, other mammals and some bird species are dead-end hosts. Lineage 1 WNV strains have predominated in Europe since the 1960s. However, in 2004 lineage 2 strains emerged in Hungary and Russia, respectively, spreading since then to a number of neighbouring countries (e.g., Austria, Greece, Italy, Serbia and Romania). Wild bird mortality is a hallmark of North American WNV outbreaks, a feature uncommon in Europe. This study aimed to compare the course of infection of lineage 1 (NY99) and lineage 2 (Austria/2008) WNV strains in the house sparrow, a bird species common in Europe and North America. House sparrows were inoculated with either NY99 or Austria/2008 WNV strains, or sham-inoculated, and clinical and analytic parameters (viraemia, viral load, antibodies) were examined until 14 days after inoculation. Although all inoculated sparrows became infected, no mortality or clinical signs were observed due to the infection. However, the magnitude and duration of viraemia were higher for NY99 - than for Austria/2008 - infected birds. The house sparrow proved to be a competent host for both strains, although the competence index calculated for NY99 was higher than for Austria/2008. Viral load in tissues and swabs was also higher in NY99-inoculated sparrows. In conclusion, the house sparrow is a convenient avian model for studying host competence of WNV strains. The observed differences between NY99 and Austria/2008 strains might have important epidemiological consequences for disease incidence and dispersal capacity.
西尼罗河病毒（WNV）是一种人畜共患病病原体，在蚊子和鸟类之间维持着地方性循环；人类、马、其他哺乳动物和一些鸟类是终末宿主。自 20 世纪 60 年代以来，1 型WNV 株系在欧洲占主导地位。然而，2004 年，2 型株系分别在匈牙利和俄罗斯出现，此后传播到许多邻国（如奥地利、希腊、意大利、塞尔维亚和罗马尼亚）。野生鸟类死亡是北美 WNV 暴发的一个标志，这在欧洲并不常见。本研究旨在比较 1 型（NY99）和 2 型（奥地利/2008）WNV 株系在麻雀（一种在欧洲和北美常见的鸟类）中的感染过程。用 NY99 或奥地利/2008 WNV 株系或假接种麻雀，检查临床和分析参数（病毒血症、病毒载量、抗体），直到接种后 14 天。尽管所有接种的麻雀都感染了，但由于感染，没有观察到死亡率或临床症状。然而，NY99 感染的鸟类的病毒血症程度和持续时间高于奥地利/2008 感染的鸟类。麻雀被证明是两种株系的有效宿主，尽管 NY99 的效价指数高于奥地利/2008。NY99 接种麻雀的组织和拭子中的病毒载量也更高。总之，麻雀是研究 WNV 株系宿主易感性的一种方便的禽类模型。观察到的 NY99 和奥地利/2008 株系之间的差异可能对疾病发病率和传播能力产生重要的流行病学后果。
