First detection of bird flu on Hawaiʻi Island, at Hilo Wastewater Treatment Plant

The County of Hawaiʻi’s Department of Environmental Management is working closely with the Hawaiʻi State Department of Health after the detection of H5 avian influenza (bird flu) in a sample of influent collected from the Hilo Wastewater Treatment Plant on Dec. 2.  

This marks the first detection of bird flu on Hawaiʻi Island. The sample was taken from the inflow into the treatment plant, before the treatment process. The Hilo Wastewater Treatment Plant uses a disinfection process, including chlorination, specifically designed to kill or inactivate viruses, such as bird flu. 

According to DOH, wastewater testing cannot determine if the detection is specifically the Highly Pathogenic Avian Influenza (HPAI) H5N1 subtype of bird flu virus which was recently found on Oʻahu.   

The presence of the H5N1 virus in Hawaiʻi was first confirmed in November 2024 in a backyard flock of birds in Central Oʻahu. That virus strain was a different genotype of the virus that has infected birds and dairy cows on the US mainland.

The risk to public health remains low, according to DOH. However, HPAI can cause severe impacts to certain bird populations such as poultry. Commercial poultry producers and residents with backyard flocks are strongly advised to increase biosecurity measures to reduce the likelihood of infection. HPAI can also infect dairy cows. While pasteurized milk is safe, raw milk should be avoided.

To ensure timely detection and response, DOH has increased the plant’s testing frequency from once a week to twice a week. We understand the community’s concerns and are committed to providing updates as we work alongside DOH and other partners. For any wastewater questions, please contact DEM at 808-961-8800, Monday to Friday from 7:45 a.m. to 4:30 p.m. 

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. 

Resources on avian influenza: 

• HDOA, Animal Disease Control: https://hdoa.hawaii.gov/ai/ldc/avian-influenza-information/ 
• HDOA, Avian Influenza – Biosecurity in The Context of Animal Agriculture: https://hdoa.hawaii.gov/ai/ldc/adconcerns/aiinfo/biosec/ 
• DOH avian influenza information: https://health.hawaii.gov/docd/disease_listing/avian-influenza/ 
• Centers for Disease Control and Prevention: https://www.cdc.gov/bird-flu/index.html 
• US Department of Agriculture: https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza