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Evidence for interannual persistence of infectious influenza A viruses in Alaska wetlands

September 7, 2021

Influenza A viruses (IAVs) deposited by wild birds into the environment may lead to sporadic mortality events and economically costly outbreaks among domestic birds. There is a paucity of information, however, regarding the persistence of infectious IAVs within the environment following deposition. In this investigation, we assessed the persistence of 12 IAVs that were present in the cloaca and/or oropharynx of naturally infected ducks. Infectivity of these IAVs were monitored over approximately one year when held in five water types: (1) distilled water held in the lab at 4 ºC and (2–5) filtered surface water from each of four Alaska sites and maintained in the field at ambient temperature. By evaluating infectivity of IAVs in ovo following sample retrieval at four successive time points, we observed successive declines in IAV infectivity through time. Many viruses persisted for extended periods, as evidenced by ≥ 25% of IAVs remaining infectious in replicate samples for each treatment type through three sampling time points (144–155 days post-sample collection) and two viruses remaining viable in a single replicate sample each when tested upon collection at a fourth time point (361–377 days post-sample collection). The estimated probability of persistence of infectious IAVs in all five water types was estimated to be between 0.25–0.75 during days 50–200 post-sample collection as inferred through Kaplan-Meier survival analysis. Our results provide evidence that IAVs may remain infectious for extended periods, up to or even exceeding one year, when maintained in surface waters under ambient temperatures. Therefore, wetlands may represent an important medium in which infectious IAVs may reside outside of a biotic reservoir.

Citation Information

Publication Year 2022
Title Evidence for interannual persistence of infectious influenza A viruses in Alaska wetlands
DOI 10.1016/j.scitotenv.2021.150078
Authors Andrew M. Ramey, Andrew B. Reeves, Benjamin Joel Lagassé, Vijay P. Patil, Laura E. Hubbard, Dana W. Kolpin, R. Blaine McCleskey, Deborah A. Repert, David E. Stallknecht, Rebecca L. Poulson
Publication Type Article
Publication Subtype Journal Article
Series Title Science of the Total Environment
Index ID 70223773
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Biology WTEB; Central Midwest Water Science Center; Upper Midwest Water Science Center