In this investigation, we used a combination of field- and laboratory-based approaches to assess if influenza A viruses (IAVs) shed by ducks could remain viable for extended periods in surface water within three wetland complexes of North America. In a field experiment, replicate filtered surface water samples inoculated with duck swabs were tested for IAVs upon collection and again after an overwintering period of approximately 6–7 months. Numerous IAVs were molecularly detected and isolated from these samples, including replicates maintained at wetland field sites in Alaska and Minnesota for 181–229 days. In a parallel laboratory experiment, we attempted to culture IAVs from filtered surface water samples inoculated with duck swabs from Minnesota each month during September 2018–April 2019 and found monthly declines in viral viability. In an experimental challenge study, we found that IAVs maintained in filtered surface water within wetlands of Alaska and Minnesota for 214 and 226 days, respectively, were infectious in a mallard model. Collectively, our results support surface waters of northern wetlands as a biologically important medium in which IAVs may be both transmitted and maintained, potentially serving as an environmental reservoir for infectious IAVs during the overwintering period of migratory birds.

中文翻译：

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甲型流感病毒在北美北部湿地的传染性持续了七个多月

在这项调查中，我们结合了基于实地和实验室的方法来评估鸭子散发的甲型流感病毒 (IAV) 是否可以在北美三个湿地复合体的地表水中长时间保持活力。在田间试验中，在收集时和在大约 6-7 个月的越冬期后再次对接种鸭拭子的过滤地表水样本进行 IAV 测试。从这些样本中分子检测并分离出许多 IAV，包括在阿拉斯加和明尼苏达州的湿地现场保存 181-229 天的复制品。在平行实验室实验中，我们尝试在 2018 年 9 月至 2019 年 4 月期间每个月从用来自明尼苏达州的鸭拭子接种的过滤地表水样本中培养 IAV，发现病毒活力每月下降。在一项实验性挑战研究中，我们发现 IAV 在阿拉斯加和明尼苏达湿地的过滤地表水中分别保持 214 天和 226 天，在野鸭模型中具有传染性。总的来说，我们的研究结果支持北部湿地的地表水是一种重要的生物学介质，IAV 可以在其中传播和维持，可能成为候鸟越冬期间传染性 IAV 的环境储存库。