The arrival of highly pathogenic avian influenza to Hawaii poses a significant threat to poultry and wild birds but is not an immediate threat to humans, according to expert Axel Lehrer, a professor of tropical medicine and medical microbiology at the University of Hawaii at Manoa’s John A. Burns School of Medicine.
“We have to be very clear that so far the virus has only been identified in animals and poultry, so based on the genetic lineage that the virus seems to stem from, it is not directly linked to recent outbreaks on the mainland or in Canada,” Lehrer said in a video release issued by UH on Monday.
Authorities nationwide have been tracking and responding to an outbreak of the disease in the United States since 2022.
The first-ever detection of H5 avian influenza in the state was confirmed by the National Wastewater Surveillance System on Nov. 12 from a sample taken at the Wahiawa Wastewater Treatment Plant five days earlier. The testing could not determine whether the H5 virus detected was HPAI, also known as H5N1.
The U.S. Department of Agriculture’s National Veterinary Service Laboratories confirmed to the state Department of Agriculture on Nov. 15 that HPAI was detected in a backyard flock of birds in Wahiawa. All birds on the property were subsequently culled and the property itself was cleaned and disinfected.
A second case of the virus, which causes severe illness with a high mortality rate among affected birds, was confirmed in a wild duck on the North Shore on Nov. 25.
Lehrer said the virus currently has limited ability to spread to humans or mammals.
“Various studies have happened over the years and so far, the virus has not gained the fitness to really replicate in mammals,” he said.
People who do get infected are typically those who work professionally on a day-to-day basis with poultry or other birds. Symptoms in humans — including conjunctivitis and upper respiratory symptoms like sore throat and cough — tend to be mild, according to the Centers for Disease Control.
Sustained human-to-human transmission has not been reported.
It is believed that the virus arrived in Hawaii via bird migration via the Pacific flyway, a migratory path from the continental U.S.
HDOA has been working with DOH and has partnered with veterinary staff at the University of Hawaii College of Tropical Agriculture and Human Resilience to assist in education and outreach to poultry operations, backyard flock owners and other animals susceptible to the virus.
Since 2015, several agencies have been conducting routine surveillance for avian influenza statewide, including HDOA, two branches of the U.S. Department of Agriculture and the U.S. Geological Survey.
To report multiple or unusual illnesses in poultry, livestock, or other wild birds or animals, contact HDOA Animal Industry Division at 808-483-7102, Monday to Friday from 7:45 a.m. to 4:30 p.m., or 808-837-8092 during non-business hours and holidays.
Residents who believe they may have been exposed to sick birds or other wildlife should contact the Disease Outbreak Control Division Disease Reporting Line at 808-586-4586 for additional guidance.
Michael Tsai covers local and state politics for Spectrum News Hawaii. He can be reached at michael.tsai@charter.com.
