Three state agencies are on alert after a second case of highly pathogenic avian influenza (HPAI) was confirmed in a migratory duck – this time on the island of Maui. This is the first confirmed detection of H5N1 on Maui.

The Northern pintail (koloa māpu) was found along the Wailea shoreline and submitted to the U.S. Geological Survey’s National Wildlife Health Center – Honolulu Field Station. Samples were sent to the National Wildlife Health Center in Madison, Wisconsin, where it tested positive for influenza H5. The National Veterinary Services Laboratories in Iowa later confirmed the bird was infected with the H5N1 virus.

H5N1 is a highly infectious and often lethal subtype of influenza A that primarily affects birds but can sometimes be transmitted to humans. H5N1 was first detected in Hawai?i in November 2024 in a backyard flock in Central O?ahu and subsequently in a hybrid duck from the north shore of O?ahu. This Maui case follows the October 2025 confirmation of H5N1 in another koloa māpu found on O?ahu at the University of Hawai?i Mānoa campus.

This year to date, the USGS has tested 77 birds for influenza all of which have been negative except for the Maui koloa māpu. Given these data, the risk of infection to humans and poultry remains low.

The Hawai´i Department of Health (DOH), Department of Agriculture & Biosecurity (DAB) and Department of Land and Natural Resources (DLNR) continue coordinated monitoring of public health reports, poultry operations and wild bird populations for any signs of virus spread.

During the Hawai?i migratory bird season, migratory birds may carry diseases to the islands, so the public should remain vigilant.