On May 22, 2024, Australia reported its first confirmed case of human infection with avian influenza A(H5N1) virus to the World Health Organization (WHO). This incident marked a significant development in the epidemiological landscape of Australia, highlighting the nation´s public health challenges and response mechanisms. This case also highlights the broader context of H5N1´s global spread, with earlier cases reported in the United States and Vietnam in 2024.

The notification came from Australia´s International Health Regulations (IHR) National Focal Point (NFP). This case involved a 2.5-year-old female child with no underlying health conditions. The child had a history of travel to Kolkata, India, from February 12 to February 29, 2024, and had returned to Australia on March 1, 2024. Upon her return, she was admitted to a hospital in Victoria on March 2, 2024, because of symptoms. On March 4, she was transferred to the intensive care unit of a referral hospital in Melbourne because of worsening symptoms. The patient was discharged after a 2.5-week hospital stay and is now clinically well. The WHO Collaborating Centre (WHO CC) for Reference and Research on Influenza in Australia initially notified the NFP of a suspected case on May 17, 2024. The H5N1 infection was confirmed by the Victorian Department of Health on May 18, 2024. Subsequently, the NFP of Australia informed the NFP of India about the confirmed case on May 21, 2024, and WHO was notified the following day.