Avian flu virus detected in Kauai wastewater, state says

A wastewater sample from Kauai County tested positive for the H5N1 avian influenza last month.

It is the first detection of the virus associated with this year’s migratory bird season, which typically runs from August to May, as well as the first detection of genotype D1.1 in Hawaii, according to the Hawaii Department of Health.

DOH said the wastewater detection does not necessarily mean that live, infectious virus is present, nor does it necessarily confirm there is a clinical case or community transmission in Hawaii.

It serves, however, as an early indicator that the risks are present, prompting increased awareness and monitoring.

“While the risk to the public remains low, avian influenza can cause severe illness and high mortality among certain bird populations, including poultry,” said DOH Deputy State Epidemiologist Nathan Tan in a news release. “Commercial poultry producers and residents with backyard flocks are strongly advised to increase biosecurity measures to reduce the risk of infection.”

He added, “Avian influenza can also infect dairy cows and while pasteurized milk is safe to consume, raw milk should be avoided.”

The sample was collected from East Kauai on Oct. 14, and DOH was notified of the result on Monday.

Since the East Kauai wastewater treatment is an open system, health officials said, the detection could be associated with various sources — including contaminated products, waste from infected animals, or waste from infected people.

Wastewater testing itself cannot determine whether the source of the genetic material was animal, human or environmental contamination.

In the U.S., genotype D1.1 has emerged as the predominant strain of Highly Pathogenic Avian Influenza in domestic poultry and infected wildlife. In addition, there have been isolated events of D1.1 infecting dairy cattle on the U.S. continent.

DOH said it continues to test milk from the local dairy, and has not detected H5N1.

Hawaii detected its first outbreak of avian influenza in November 2024 at Susie’s Duck Sanctuary, a rescue organization previously located in Wahiawa.

The virus, which was then confirmed as the genotype A3 strain, wiped out a backyard flock of rescued ducks and geese, and was detected in a wild zebra bird, as well.

It has been detected as well, in a wild duck tested at James Campbell National Wildlife Refuge on Oahu’s North Shore, along the Wailea shoreline on Maui, and in a Hawaiian duck found sick at Hanalei Wildlife Refuge on Kauai.

DOH has reported no cases of avian influenza among wildlife or domestic poultry so far this year.

Health officials said genomic sequencing conducted by the University of Missouri identified genotype D1.1 in the wastewater sample collected Oct. 14. A subsequent sample was collected on Oct. 21, with results still pending.

State officials say multiple sick or dead birds, or unusual illness or deaths among poultry should be reported to the Hawaii Department of Agriculture and Biosecurity Animal Industry Division at 808-483-7100 or [email protected]. On holidays, call 808-837-8092.

Residents who develop symptoms such as fever, cough, or conjunctivitis after exposure to sick birds should contact the DOH Disease Reporting Line at 808-586-4586 for guidance.