On January 7th the USDA-APHIS presented a webinar on avian influenza with specific reference to the late December 2021 limited outbreak of HPAI on the Avalon Peninsula of the Province of Newfoundland and Labrador. Concern was raised following molecular assay of the H5N1 virus, that disclosed that the pathogen comprised a genome of Eurasian origin. This virus, responsible for extensive outbreaks in Europe, Africa and Asia has now been introduced into North America. Trans-Atlantic spread was attributed to migration of wild waterfowl possibly through sequential contact among diverse species extending from Northern Europe through Iceland and Greenland to Northeast Canada. The presence of this H5N1 strain in the Atlantic flyway has implications for the Maritime Provinces of Canada, the New England states and ultimately the entire Atlantic Seaboard of the U.S.
Dr. Jack Shere Associate Administrator of the USDA-APHIS noted in his introduction to the Webinar that the infection is "creeping closer to home and on our doorstep". On a reassuring note he confirmed that the U.S. is in a far better position with regard to preparation for an outbreak of highly pathogenic avian influenza (HPAI) than in 2015. It is noted that this epornitic cost more than $3 billion to control. Economists suggest that an equivalent amount was borne by consumers paying higher prices for eggs and poultry meat during the outbreak.
Following the epornitic of HPAI in 2015, Canada and the U.S. established bilateral agreements involving common language on export-import certificates and will establish procedures in the event of outbreaks of catastrophic diseases. According to a 2018 protocol regionalization and zonation are permitted to allow trade with appropriate precautions to prevent transmission of HPAI and other diseases.
Surveillance of wild birds for the presence of avian influenza is considered an essential component of a preventive program. From July 2021 through March 2022, USDA-APHIS in collaboration with the Department of Interior and state agencies planned to examine 9,000 samples from free-living birds among sixteen eastern seaboard states. From July to September 2021, 2,280 samples were examined in nine states ranging from Maine southwards to North Carolina. Of these specimens, 44 percent yielded low-pathogenicity H5 strains of avian influenza but with no evidence of H7 strains. The fall survey will encompass sixteen states following the southward migration of waterfowl. Of 2,140 samples examined to date, 10 percent yielded H5 avian influenza strains all characterized as low-pathogenic and 0.7 percent of the samples were H7 strains. During the upcoming period January through March 2022, two thousand samples will be examined from migratory birds in fourteen states.
Early detection of avian influenza is critical to planning and implementing an effective eradication campaign. APHIS will continue the live-bird market surveillance program. The National Poultry Improvement Program will require designated samples from breeding flocks. Surveillance will be maintained by state laboratories based on postmortem examination of birds submitted for diagnosis. Many states require routine sampling of flocks before either slaughter or interstate movement State poultry associations are promoting the imperative to report unusual mortality or deviation from acceptable performance standards to appropriate veterinary authorities followed by diagnostic intervention to exclude avian influenza.
While it is our collective and earnest hope that the commercial industry and the U.S. will be spared exposure to avian influenza, the probability of transmission from migratory birds is increasing, confirming the need to implement effective structural and operational biosecurity on all poultry facilities.