Avian influenza H5N1 in Heard Island southern elephant seals
Australian authorities have confirmed that highly pathogenic avian influenza (HPAI) H5N1 is responsible for the recent unexplained deaths of southern elephant seals on Heard Island in the southern Indian Ocean. The event was first noted at the end of October, when an abnormal mortality cluster among elephant seal pups was reported on the remote subantarctic island.
Samples collected on-site were transferred to Australia for diagnostic evaluation. Scientists at the CSIRO’s Australian Centre for Disease Preparedness subsequently identified HPAI H5N1 in the submitted samples. This marks a significant detection in a vulnerable marine mammal population inhabiting one of the world’s most isolated ecosystems.
The confirmation raises concerns regarding possible viral incursion into subantarctic wildlife and underscores the need for continued surveillance in marine mammal colonies across the region.
