H5N1

27 Sep 2026

Government data North America

The U.S. mammal H5N1 detection table is still changing—and still incomplete

Evidence: Government data
Geography: United States
System: Wildlife, captive mammals and avian-influenza surveillance

WHAT THE EVIDENCE SAYS

USDA APHIS updated its mammal HPAI detections page on September 25. The table includes recent 2026 detections in mammals and explicitly warns that data may be incomplete and that additional detections will be added.

WHY IT MATTERS / OUR READ

The useful signal is surveillance breadth, not a claim of sustained mammal transmission. A dynamic cross-species detection ledger helps identify where wildlife, domestic animals and disease-monitoring systems intersect.

CAVEATS / UNCERTAINTY

Detection does not establish onward mammal-to-mammal transmission, population-level impact or a complete incidence picture. The federal table is explicitly incomplete and is updated as reports arrive.

SOURCE

USDA APHIS
View original evidence ↗

EvidenceGovernment dataGeographyUnited StatesSystemWildlife, captive mammals and avian-influenza surveillance WHAT THE EVIDENCE SAYS USDA APHIS updated its mammal HPAI detections page on September 25. The table includes recent 2026 detections

Read the Wild Lands assessment →

20 Sep 2026

Government data

Australia’s H5N1 response is entering a multi-species wildlife phase

Evidence: Government data
Geography: Australia
System: Wild birds, marine mammals and terrestrial wildlife disease surveillance

WHAT THE EVIDENCE SAYS

Australia's national bird-flu surveillance dashboard reported 583 confirmed H5 wildlife events as of September 18, with detections spread across multiple states and territories. Separate expert reporting on the Australian response has documented spillover detections in mammalian wildlife, including seals and other species, while authorities have not reported sustained mammal-to-mammal transmission.

WHY IT MATTERS / OUR READ

Worth keeping in the back of your mind because the management problem is shifting from an avian outbreak to a broader wildlife-interface surveillance challenge. The useful next evidence will be whether mammalian infections remain independent spillovers, which species and places become recurrent, and how carcass, rehabilitation and biosecurity systems adapt.

CAVEATS / UNCERTAINTY

A reported 'event' is not the same as an individual infected animal, and testing intensity changes after an outbreak becomes established. Mammalian detection does not imply mammal-to-mammal transmission, and current surveillance counts should not be read as a population-impact estimate.

SOURCE

Australian Department of Agriculture, Fisheries and Forestry
View original evidence ↗

Global Virus Network · Expert statement
View supporting source ↗

National surveillance had recorded 583 confirmed wildlife H5 events by September 18, while detections in several mammal species are widening the ecological questions even without evidence of sustained mammal-to-mammal transmission.

Read the Wild Lands assessment →

The U.S. mammal H5N1 detection table is still changing—and still incomplete

WHAT THE EVIDENCE SAYS

WHY IT MATTERS / OUR READ

CAVEATS / UNCERTAINTY

SOURCE

Australia’s H5N1 response is entering a multi-species wildlife phase

WHAT THE EVIDENCE SAYS

WHY IT MATTERS / OUR READ

CAVEATS / UNCERTAINTY

SOURCE

Follow the systems. Find the connections.