State health officials said Tuesday night that they have detected H5 avian influenza, commonly known as bird flu, in wastewater test samples on Oahu for the first time.

A nationwide outbreak of avian influenza has spread among birds and mammals on the mainland, but this is the first time it has been detected in Hawaii, state Department of Health officials said in a news release.

Human cases of bird flu have been reported among those working closely with infected animals on the mainland, but there is no evidence of sustained human-to-human transmission of H5N1 in the United States, officials said.

The Oahu wastewater specimen was collected Thursday, and the department received the result Tuesday, they said.

“Wastewater sampling is routinely performed across Hawaii as part of ongoing surveillance for infectious diseases including avian influenza,” officials said in the news release. “H5N1, also called Highly Pathogenic Avian Influenza (HPAI), is one type of H5 avian influenza. Whether this detection is HPAI is unable to be determined from wastewater testing.”

They said the positive result requires further investigation “to determine whether this detection is H5N1-related, and an opportunity to reinforce prevention measures, particularly among persons at increased risk of exposure.”

“To date, Hawaii has been the only state without H5N1 avian influenza detected in birds or animals. There are no reports of human or animal H5N1 cases in Hawaii and the overall risk of H5N1 to Oahu and state residents remains low,” health officials said.

While the current risk of transmission to Hawaii residents is low, the department said residents should follow these best practices when around animals or when consuming animal products:

>> In general, do not touch birds, livestock or wild animals that are sick or dead without personal protective equipment.

>> Report sick pets to their veterinarian.

>> Contact the Animal Industry Division at the state Department of Agriculture at 808-483-7106, 7:45 a.m. to 4:30 p.m. Monday to Friday, or 808-837-8092 during nonbusiness hours and holidays to report multiple or unusual illnesses or deaths in poultry, livestock or wild birds or animals.

>> Do not touch or consume raw milk or raw milk products, especially from animals with confirmed or suspected avian influenza infection. Pasteurized milk products are safe.

>> Contact the Health Department immediately at 808-586-4586 if you develop symptoms of avian influenza and have been in close contact with sick or dead animals.

Officials said symptoms of avian influenza can include fever, cough, sore throat and conjunctivitis. Antiviral flu treatment is available and recommended as soon as possible for people with suspected or confirmed avian influenza infection, they said.