Argentina has lost its official status as free of Highly Pathogenic Avian Influenza in commercial poultry following a confirmed outbreak in Buenos Aires province, according to an official notification submitted to the World Organisation for Animal Health on February 23. The infection struck a commercial breeding farm housing approximately 30,000 birds, marking a major setback for the country’s disease-free status.
Commercial Farm Outbreak Details
According to Argentina’s National Service of Agri-Food Health and Quality, the outbreak began on a heavy breeding stock premises in Buenos Aires province. Farm operators alerted veterinary authorities after recording 694 bird deaths alongside clinical signs typical of avian influenza. Laboratory testing subsequently confirmed the presence of an H5 variant of Highly Pathogenic Avian Influenza within the 30,000-bird flock. SENASA listed the source of the infection as unknown or inconclusive. Under emergency biosecurity protocols reported by the World Organisation for Animal Health, authorities are depopulating all birds on the premises to contain the spread.
Wild Bird Detections Across Reserves
In a separate wild bird incident tracked by the World Organisation for Animal Health, authorities confirmed H5 infections within wild populations at the Laguna Salada Grande Reserve. Surveillance intensified after a fulvous whistling duck showed neurological signs on February 9 before being preyed upon. Subsequent monitoring revealed 25 additional wild birds testing positive for the virus. Affected species at the reserve included:

- Coscoroba swans
- Black-necked swans
- Brown-hooded gulls
This cluster represents the first confirmed wild bird detection of Highly Pathogenic Avian Influenza in Argentina since October 2025, effectively ending the country’s national disease-free status that had been active since September 2025.
Broader Regional Context and Precedent
For comparison, the National Veterinary Services Laboratories confirmed H5N1 detections in alpacas on a premises in May 2024 where affected poultry were depopulated, sharing the B3.13 viral genome sequence circulating in dairy cattle.
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