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Volume 32, Number 11—November 2026
Research Letter
Evidence of Exposure to Highly Pathogenic Avian Influenza H5 Viruses in East Greenland Polar Bears
, Charlene Ranadheera, Nathalie Bastien, Marcy Zirino, Emily Jenkins, Morten Tryland, Rune Dietz, Jens Søndergaard, and Christian Sonne
Table
Antibodies detected for influenza A viruses and H5 viruses in 12 polar bears sampled in the Ittoqqortoormiit region of East Greenland during 2024–2025 and submitted to the Canada’s National Microbiology Laboratory for screening*
| Bear ID | Sex | Year | cELISA† | HI assay‡ |
|||
|---|---|---|---|---|---|---|---|
| A/British_Columbia/PHL2032/2024 (clade 2.3.4.4b H5) | A/Texas/37/2024 (clade 2.3.4.4b H5) | A/Vietnam/1203/2004 (clade 1 H5) | A/Anhui/01/13 (H7N9) | ||||
| 63931 | M | 2024 | 3 | 20 | <20 | <20 | 20 |
| 63938 | M | 2024 | 8 | <20 | <20 | <20 | <20 |
| 63942 | M | 2024 | 32 | <20 | <20 | <20 | <20 |
| 67552 | M | 2025 | 10 | 40 | 40 | 5 | <5 |
| 67554 | F | 2025 | 24 | 20 | 10 | <5 | <5 |
| 67555 | M | 2025 | 5 | 160 | 40 | <5 | <5 |
| 67556 | M | 2025 | 40 | 20 | 10 | <5 | <5 |
| 67559 | M | 2025 | 10 | 80 | 80 | 5 | <5 |
| 67563 | M | 2025 | 31 | 160 | 160 | 20 | <5 |
| 67560 | M | 2025 | 98 | <5 | <5 | <5 | <5 |
| 67561 | M | 2025 | 71 | 10 | 5 | <5 | <5 |
| 67565 | M | 2025 | 96 | <5 | <5 | <5 | <5 |
*Bold indicates a positive result. cELISA, competitive ELISA; HI, hemagglutination inhibition. †cELISA results (ID Screen Influenza A Antibody Competition Multi-Species; Innovative Diagnostics, https://www.innovative-diagnostics.com) are represented as the signal-to-noise ratio (i.e., optical density of the sample / average optical density of the negative controls) × 100). ‡HI assay results are represented as the endpoint dilution factor (2-fold serial dilution).