Global Virus Network Reports Detections of H5N1 in Australian Mammals

TAMPA, Fla., Sept. 18, 2026 /CourierPR/ -- The Global Virus Network (GVN) has issued a statement regarding the detection of highly pathogenic avian influenza A (H5N1) in several mammal species in Australia. The virus, which has been spreading globally, was first detected in a long-nosed fur seal on August 23, marking the first confirmed detection in a mammal in Australia. Subsequent detections included a red fox in metropolitan Adelaide, a common dolphin at Goolwa, and a second fox at Normanville. On September 13, Australian authorities confirmed the first detection in an Australian sea lion, an endangered species, at Seal Bay on Kangaroo Island.

The virus has since been found in a growing range of mammals worldwide, including seals and other marine mammals, dairy cattle, cats, and wild carnivores. The detections in Australia show the virus infecting several mammal species within weeks of its first reported appearance in the country's wildlife. The Australian Centre for Disease Control continues to assess the risk to people as low, reporting no evidence that the virus circulating in Australia has changed to infect people more easily. The World Health Organization reports no sustained person-to-person transmission of H5N1.

Michelle Wille, Ph.D., an avian influenza researcher affiliated with the University of Melbourne and the WHO Collaborating Centre for Reference and Research on Influenza and the Peter Doherty Institute for Infection and Immunity, a GVN Center of Excellence in Australia, stated, "Given what we have seen with this H5N1 genotype in seal and sea lion populations overseas, a spillover into Australian marine mammals was a possibility we had been concerned about and actively monitoring for. While it is sobering to see that possibility become a reality, the priority now is detailed genomic analysis of this and any future detections. We need to closely monitor for mutations associated with better adaptation to mammals and determine whether infections represent separate spillover events from birds or evidence of transmission between seals. That distinction will be critical to understanding the risk posed by the virus as it continues to circulate in wildlife."

Australia first detected H5N1 clade 2.3.4.4b in wild seabirds in June. As of September 17, Australia had reported 576 confirmed events in wildlife, including mass mortality events in greater crested terns. There have been no detections in Australian poultry or the agricultural production system. Australian authorities report no evidence of mammal-to-mammal transmission of the virus in Australia.

In April 2025, GVN published an analysis in The Lancet Regional Health, Americas calling for stronger surveillance, biosecurity, genomic monitoring, and preparedness as H5N1 spread. In April 2026, GVN issued a statement on H5N1 vaccine developments, emphasizing the need for continued vaccine development and broader pandemic preparedness. GVN is a worldwide coalition comprising 90+ Virology Centers of Excellence and Affiliates across 40+ countries, whose mission is to facilitate pandemic preparedness against viral pathogens and diseases that threaten public health globally. The organization provides the essential expertise required to discover and diagnose viruses that threaten public health, understand how such viruses spread illnesses, and facilitate the development of diagnostics, therapies, and treatments to combat them. GVN coordinates and collaborates with local, national, and international scientific institutions and government agencies to provide real-time virus informatics, surveillance, and response resources and strategies. The GVN is a non-profit 501(c)(3) organization.