Bird Flu Confirmed in Hawaii as US Cases Climb

Test tube labelled 'Bird Flu' in front of U.S. flag in this illustration taken on June 10, 2024. Dado Ruvic/Illustration/Reuters

Hawaii has reported an avian influenza outbreak among domesticated birds, joining a number of other U.S. states that have seen millions of birds infected over the past weeks.

The outbreak of highly pathogenic avian influenza (HPAI)—commonly known as bird flu—was discovered among non-poultry birds in Honolulu County, the Animal and Plant Health Inspection Service (APHIS) said in a Nov. 18 statement.

The agency, which operates under the U.S. Department of Agriculture, said it was working closely with state officials for a joint incident response effort.

“This is the first case of HPAI in domestic birds in Hawaii during this outbreak, which began in February 2022,” the statement said.

Hawaii’s Department of Health (DOH) issued an alert on Nov. 17, warning about potential public exposure to avian influenza. The department said some of the infected birds were present at the Mililani Pet Fair held on Nov. 2.

At the time, the birds did not show any signs of infection. Symptoms were only detected several days after the fair was over and as such, the agency sees a low potential of avian flu spreading to humans.

“However, out of an abundance of caution, DOH recommends that individuals who attended the fair and touched a duck or goose monitor for influenza-like illness (ILI) and conjunctivitis (pink eye) symptoms,” the department said.

If anyone displays symptoms of avian flu, they should be isolated at home, it added. Symptoms typically emerge 2-5 days after getting exposed to infected animals and include sore throat, cough, and fever. Sometimes, symptoms can take longer, like 10 days, to emerge.

According to APHIS data, 49 flocks were confirmed to have had HPAI nationwide over the past 30 days, as of Nov. 21. In total, an estimated 6.2 million birds have been infected. The majority of cases have been in California, where 26 flocks, accounting for 5.21 million birds, were affected.

Other states that have reported outbreaks since last week are Alaska, Illinois, South Dakota, Washington, Minnesota, Utah, Colorado, Arizona, Oregon, and Montana.

The largest of these cases was in Utah, where an outbreak affected 37,500 birds. The second biggest was in Illinois, with 5,600 cases, followed by Montana, with 280 infected birds. In all other cases, the number of affected birds was in double digits or lower.

APHIS also said that wild birds can be infected with HPAI and show no signs of illness.

“They can carry the disease to new areas when migrating, potentially exposing domestic poultry to the virus,” the APHIS said on Nov. 19.

Snow geese are seen during their migratory movements at the Reservoir Beaudet, in Victoriaville, Que., Nov. 1, 2023. Bernard Brault/The Canadian Press

The U.S. Centers for Disease Control and Prevention (CDC) said that bird flu is widespread in wild birds, causing outbreaks in poultry and U.S. dairy cows. Recent human cases have also involved U.S. dairy and poultry workers.

Human Infections

According to the CDC, 53 people in the United States have been confirmed with avian influenza infection as of Nov. 19.

In 21 of these incidents, infected poultry was the source of the infection, while in 30 cases, it was dairy cows.

California had the most number of cases with 27 infections, followed by Washington with 11, Colorado 10, and Michigan registering two incidents. Missouri, Oregon, and Texas saw one infection each.

“All recent cases have occurred in workers on affected farms. All available data so far suggest sporadic instances of animal-to-human spread,” the CDC said in a Nov. 18 situation update.

“These farm workers all described mild symptoms, many with eye redness or discharge (conjunctivitis). Some workers who tested positive in Washington reported some mild upper respiratory symptoms. None of the workers were hospitalized,” the CDC said.

On Tuesday, the California Department of Public Health (CDPH) said they identified a potential case of bird flu in a child who displayed mild symptoms.

The minor, from Alameda County, has been treated and is currently recovering, the agency said. The child is not known to have come into contact with any infected animal. Officials are looking at wild birds as a potential source of exposure.

All family members were tested, with everyone testing negative.

“It’s natural for people to be concerned, and we want to reinforce for parents, caregivers, and families that based on the information and data we have, we don’t think the child was infectious—and no human-to-human spread of bird flu has been documented in any country for more than 15 years,” said Dr. Tomas Aragon, state public health officer and director of CDPH.