Human Health Surveillance During Animal Disease Emergencies: Minnesota Department of Health Response to Highly Pathogenic Avian Influenza Outbreaks, 2015 and 2022-2023

Objectives: Highly pathogenic avian influenza (HPAI) poses an occupational risk for poultry workers, responders, and others in contact with infected birds. The objective of this analysis was to describe HPAI surveillance methods and outcomes, and highlight the challenges, successes, and lessons learned during the Minnesota Department of Health's (MDH's) public health response to HPAI outbreaks in Minnesota poultry flocks in the years 2015 and 2022-2023.

Methods: During both outbreaks, MDH staff attempted to contact all potentially exposed people and conduct a standardized interview. People were considered exposed and at risk if they had entered a barn with poultry on any HPAI test-positive premises. With their consent, exposed persons were entered into illness monitoring until 10 days from their last exposure. In 2015, MDH monitored the health of poultry workers only. In the 2022-2023 response, MDH monitored the health of poultry workers, backyard flock owners, responders, and private contract workers. In 2022-2023, interview responses were entered into a REDCap (Research Electronic Data Capture) database in real time, which automatically entered the person into monitoring if they consented. Through REDCap, they received an automated email with a unique link to a short survey asking about any symptom development. Where appropriate, interview responses from poultry workers collected in 2015 were compared to interview responses from poultry workers collected in 2022-2023.

Results: From March 3 to June 5, 2015, MDH epidemiologists interviewed and evaluated 375 (86%) of 435 poultry workers from 110 HPAI-infected flocks. From March 25, 2022 through December 31, 2023, MDH epidemiologists interviewed and evaluated 649 (65%) of 992 poultry workers, responders, contractors, and backyard flock owners associated with 151 HPAI-infected flocks. Among poultry workers, self-reported personal protective equipment (PPE) usage declined significantly from 2015 to 2022-2023 (full PPE usage 51.8% vs. 23.9%, p < .01).

Conclusion: MDH's long standing relationships with animal health officials and the poultry industry resulted in strong poultry worker participation rates in surveillance efforts during HPAI outbreaks in 2015 and 2022-2023. Self-reported PPE usage was low, particularly in 2022-2023. Improvements in PPE accessibility and technology are needed to protect workers and responders in the on-going HPAI outbreak.