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，我们结合了现场和实验室的方法来评估鸭子排出的甲型流感病毒（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。在一项现场实验中，用鸭拭子接种的重复过滤地表水样本在收集时和在大约 6-7 个月的越冬期后进行了 IAV 测试。从这些样本中对许多 IAV 进行了分子检测和分离，其中包括在阿拉斯加和明尼苏达州湿地现场保存了 181-229 天的重复样本。在一项平行实验室实验中，我们尝试从 2018 年 9 月至 2019 年 4 月期间每月用明尼苏达州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，我们发现在阿拉斯加和明尼苏达州湿地过滤后的地表水中分别保存 214 和 226 天的 IAV 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作为一种重要的生物学媒介，IAV可以在其中传播和维持，并有可能在候鸟越冬期间充当传染性IAV的环境储存库。