RESUMO
BACKGROUND: The risk of infection with avian influenza A viruses currently circulating in wild and domestic birds in the Americas is considered low for the general public; however, detections in humans have been reported and warning signs of increased zoonotic potential have been identified. In December 2022, two Canada geese residing on the grounds of an urban hospital in Maine tested positive for influenza A H5N1 clade 2.3.4.4b. AIMS: Given the opportunity for exposure to staff and hospital visitors through potentially infected faeces on the property, public health authorities determined mitigation efforts were needed to prevent the spread of disease. The ensuing response relied on collaboration between the public health and animal health agencies to guide the hospital through efforts in preventing possible zoonotic transmission to humans. MATERIALS AND METHODS: Mitigation efforts included staff communication and education, environmental cleaning and disinfection, enhanced illness surveillance among staff and patients, and exposure and source reduction. RESULTS: No human H5N1 cases were identified, and no additional detections in birds on the property occurred. Hospital staff identified barriers to preparedness resulting from a lack of understanding of avian influenza A viruses and transmission prevention methods, including avian influenza risk in resident wild bird populations and proper wildlife management methods. CONCLUSION: As this virus continues to circulate at the animal-human interface, this event and resulting response highlights the need for influenza A H5N1 risk awareness and guidance for facilities and groups not traditionally involved in avian influenza responses.