Collaborative: Effects of Migratory Stress & Breeding Hormones on the Spring Recrudescence of Latent West Nile & Eastern Equine Encephalitis Virus Infections in the Gray C

东部马脑炎（EEE）病毒和西尼罗河（WN）病毒是人类、马和鸟类的疾病病原体，并通过以鸟类为食的蚊子在鸟类之间传播。鸟类是这些病毒的宿主，当病毒通过以哺乳动物和鸟类为食的蚊子从鸟类传播给马和人类时，就会发生疫情。尽管我们对这些病毒周期了解很多，但病毒在冬季存活并在温带气候下每年春季在鸟类种群中重新启动的机制尚不清楚。这是我们对每种病毒知识的最大差距，也是我们制定早期发现和预防有效战略的能力中缺失的一环。在自由放养的鸣禽中对EEE病毒进行的实地研究提供了证据，表明该病毒可以在鸟类中存活到冬季。在前几年感染的鸟类可能保持慢性感染并复发，并为春季新出现的蚊子提供感染源。鸟类潜伏性感染的复发可能是由与繁殖或迁徙等应激事件相关的激素水平升高引起的。需要实验室研究来验证这一假设。我们将以迁徙鸣禽灰猫鸟为研究对象，进行实验室实验，验证慢性感染EEE和WN病毒的灰猫鸟在迁徙条件和与繁殖相关的激素变化下会复发的预测。这项研究将通过解决直接影响人类和动物健康的生物学问题，为整个社会做出贡献。

Eastern equine encephalitis (EEE) virus and West Nile (WN) virus are disease agents of humans, horses, and birds and are transmitted among birds by bird-feeding mosquitoes. Bird populations serve as a reservoir for these viruses, and outbreaks occur when virus is transmitted from birds to horses and humans by species of mosquitoes that feed on both mammals and birds. Although we understand much about these viral cycles, the mechanism by which the viruses survive winter and are reinitiated within the bird population each spring in temperate climates is unknown. This is the greatest gap in our knowledge about each virus and the missing link in our ability to develop effective strategies for early detection and prevention. Field studies of EEE virus in free-ranging songbirds provide evidence that the virus may survive the winter in birds. Birds infected during previous years may maintain chronic infections that relapse and provide a source of infection for newly emerged mosquitoes in the spring. Relapse of latent infections in birds is likely initiated by increased levels of hormones associated with breeding or stressful events such as migration. Laboratory studies are needed to verify this hypothesis. Using a migratory songbird, the gray catbird, we will conduct laboratory experiments to test the prediction that gray catbirds chronically infected with EEE and WN virus will undergo relapse when subjected to migratory conditions and hormonal change associated with breeding. This study will contribute to society at large by addressing a biological problem that directly affects human and animal health.