Giacinti Jolene A, Jarvis-Cross Madeline, Lewis Hannah, Provencher Jennifer F, Berhane Yohannes, Kuchinski Kevin, Jardine Claire M, Signore Anthony, Mansour Sarah C, Sadler Denby E, Stevens Brian, Prystajecky Natalie A, Sarma Sailendra N, Ojkic Davor, Cortez Gabrielle Angelo P, Kalhor Marzieh, Kenmuir Ethan, Sharp Christopher M
Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment and Climate Change Canada, Government of Canada, Ottawa, Ontario, Canada.
Department of Ecology and Evolutionary Biology, University of Toronto, Canada.
One Health. 2024 Nov 12;19:100932. doi: 10.1016/j.onehlt.2024.100932. eCollection 2024 Dec.
Avian influenza viruses (AIVs) regularly circulate between wild and domestic bird populations. Following several high-profile outbreaks, highly pathogenic AIVs (HPAIV) with zoonotic potential have been the subject of increasing attention. While we know that HPAIV is transmitted between domestic birds, wildlife, and the environment, little is known about persistence and spillover/back at these interfaces. We integrated the test results of samples collected on and around an infected domestic poultry premise (IP) where H5N1 HPAIV was confirmed in a flock of poultry in 2022 in Southern Ontario, Canada to explore the transmission cycle of AIVs in wildlife and the environment. We sampled a captive flock of Mallards () that resided on site, sediment samples collected from water bodies on site, and examined samples collected through surveillance within a 100 km radius of the IP from live wild ducks and sick and dead wildlife. We found serologic evidence of H5 exposure in the captive mallards that resided on site despite no evidence of morbidity or mortality in these birds and no PCR positive detections from samples collected at two different timepoints. Genetic material from the same H5N1 HPAIV subtype circulating in the domestic birds and from low pathogenicity avian influenza viruses were detected in wetlands on site. The results of live and sick and dead surveillance conducted within a 100 km radius confirmed that the virus was circulating in wildlife before and after IP confirmation. These results suggest that biosecurity remains the most critical aspect of minimising spillover/back risk in a virus that has been shown to circulate in asymptomatic wild birds and persist in the surrounding environment.
禽流感病毒（AIVs）经常在野生鸟类和家禽种群之间传播。在几次引人注目的疫情爆发之后，具有人畜共患病潜力的高致病性禽流感病毒（HPAIV）受到了越来越多的关注。虽然我们知道高致病性禽流感病毒在家禽、野生动物和环境之间传播，但对于这些界面处的病毒持久性以及溢出/回传情况却知之甚少。我们整合了在加拿大安大略省南部一个受感染的家禽养殖场（IP）及其周边采集的样本的检测结果，该养殖场在2022年一群家禽中确诊感染了H5N1高致病性禽流感病毒，以探索禽流感病毒在野生动物和环境中的传播周期。我们对栖息在该场地的一群圈养野鸭（）进行了采样，采集了场地水体的沉积物样本，并检查了通过对距离该家禽养殖场半径100公里范围内的野生活鸭以及患病和死亡野生动物进行监测而收集的样本。我们发现，尽管这些圈养野鸭没有发病或死亡迹象，且在两个不同时间点采集的样本中没有PCR阳性检测结果，但栖息在该场地的圈养野鸭有H5暴露的血清学证据。在场地的湿地中检测到了在家禽中传播的同一H5N1高致病性禽流感病毒亚型的遗传物质以及低致病性禽流感病毒的遗传物质。在半径100公里范围内进行的活禽以及患病和死亡野生动物监测结果证实，在家禽养殖场确诊之前和之后，该病毒都在野生动物中传播。这些结果表明，生物安全仍然是将已证明可在无症状野生鸟类中传播并在周围环境中持续存在的病毒的溢出/回传风险降至最低的最关键方面。
