Avian Influenza
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Disease Reporting Line:
(808) 586-4586
What to know
- H5N1 bird flu virus has been circulating worldwide and has been causing outbreaks in poultry and dairy cows in the U.S. A limited number of human cases have occurred in 2024 and 2025 following exposure to infected animals.
- 67 confirmed total reported human cases have been detected in the United States (66 confirmed since 2024, and 67 since 2022).
- 1 death associated with H5N1 bird flu infection in the United States in January 2025.
- The Hawaii Department of Agriculture (HDOA) received confirmation from the U.S. Department of Agriculture National Veterinary Services Laboratories (NVSL) on November 15, 2024 that highly pathogenic avian influenza (HPAI) was detected in a backyard flock of various birds in Central Oahu.
- The current risk to the general public in Hawaii remains low.
- Residents are encouraged to report sick or dead birds, especially when multiple birds are affected to Hawaii Department of Agriculture (808-483-7102 during Monday to Friday from 7:45AM to 4:30PM, or 808-837-8092 during non-business hours and holidays).
- Hawaii residents who recently visited or worked on a farm in another state with known or suspected H5N1 animal infections should contact the Hawaii Department of Health’s Disease Reporting Line (808-586-4586) for a telephone risk assessment.
About This Disease
Avian influenza (bird flu) viruses occur naturally in wild birds. Avian influenza A viruses have been isolated from more than 100 different species of wild birds around the world, including ducks, geese, terns, plovers, and sandpipers. These viruses are very contagious among birds and have the potential to cause severe illness among poultry, other animal species, and even among humans exposed to the virus. For more general information about influenza A viruses: Avian Influenza Type A Viruses | Bird Flu | CDC
Current Events
H5N1 influenza A virus in the United States
The H5N1 influenza A virus has been circulating globally since it was first identified in birds in 1996. Since 2021, the H5N1 virus has been widely detected among wild birds, poultry farms, and backyard poultry flocks in the United States. In 2024, H5N1 was detected in dairy cows for the first time in the continental United States with spread to dairy cow herds in multiple states. In addition, fatal H5N1 infections among cats have been detected on affected farms. For the latest information on avian influenza in livestock, visit the USDA website.
Pasteurized milk and dairy products remain safe. Gold-standard laboratory investigations by the U.S. Food and Drug Administration have shown pasteurization to fully inactivate the H5N1 virus in milk. Therefore, the ongoing multi-state outbreak of H5N1 in dairy cows does not pose a health risk to consumers.
The first reported human infection with the H5N1 influenza A virus in the U.S. was detected in Colorado on April 28, 2022. The individual was directly exposed to infected poultry and reported fatigue as the only symptom. They were treated and since recovered.
Since April 2024, additional human H5N1 infections have been reported in the continental U.S. predominantly among workers with exposure to dairy cows or poultry with suspected or confirmed H5N1 infection. All cases have been clinically mild with symptoms of conjunctivitis or respiratory symptoms. All cases have recovered. There has been no definitive evidence of human-to-human transmission of the H5N1 virus in the U.S. Therefore, the main risk for H5N1 exposure at this time is close contact with animals infected with the virus. For current information regarding human H5N1 influenza A infections, including CDC’s latest analysis and human health risk assessment, please click here.
As of January 06, 2025, the Louisiana Department of Health confirmed the state’s first reported death from the H5N1 bird flu virus. The individual was hospitalized with severe avian influenza A (H5N1) illness. Additionally, the individual was over the age of 65 and was reported to have underlying medical conditions and exposure to a combination of a non-commercial backyard flock and wild birds. This is the first known person in the United States who has died as a result of an H5 infection. Risk to the public and human-to-human transmission remains low. For more information, visit Louisiana Department of Health’s webpage and CDC’s Newsroom.
Surveillance in the United States
The CDC continues to:
- Partner with state and local health departments in epidemiologic investigations to evaluate the public health impact of H5 cases.
- Collaborate with state and local health departments to implement active surveillance.
- Monitor potential changes that could indicate H5 viruses are becoming better adapted to mammals, which might increase their ability to spread more easily between animals-to-humans and/or human-to-human or possibly lead to more severe illnesses.
- Monitor for any viral changes that could reduce the effectiveness of flu antiviral medications or the current candidate vaccine strains.
H5N1 influenza A virus in Hawaii 2024-2025
O’ahu
HDOA received confirmation from the U.S. Department of Agriculture National Veterinary Services Laboratories (NVSL) that HPAI was detected in a backyard flock of various birds in Central O’ahu on November 15, 2024. The property involved is located within the service area of the Wahiawā Wastewater Treatment Plant, where a recent detection was reported via the National Wastewater Surveillance System. This is the first confirmed detection of the virus in Hawai‘i. The virus detected is clade 2.3.4.4b, similar to the strain that has infected wild birds, domestic poultry, and dairy cows on the U.S. mainland. Genotype results are pending.
Upon further investigation, HDOH and HDOA have identified a potential exposure to attendees of the Mililani Pet Fair held on November 02, 2024. Although some birds from the infected flock were present at the event, the first signs of infection in the flock did not appear until several days afterward. Since the birds were not showing symptoms at the time of the fair, the risk of them transmitting H5N1 to humans is considered low.
Hawai’i
On December 2, 2024, HDOH’s State Laboratories Division (SLD) confirmed the detection of the H5 bird flu virus in a wastewater sample from the Hilo Wastewater Treatment Plant on Hawai’i Island. This marked the first detection of the bird flu virus on a neighbor island. However, no confirmed cases of H5 bird flu have been found in birds, dairy cows, or humans in Hilo or Hawai’i Island to date. Infected birds have only been reported on O’ahu. The wastewater testing cannot specify whether the detected virus is the H5N1 subtype, which has been spreading globally among birds and recently been found in mammals, including dairy cows.
Kaua’i
Initial testing on December 11, 2024 detected the H5 bird flu virus at very low levels in wastewater samples from Kaua’i with similar detections on December 18, 2024 and January 8, 2025. While none of these samples have been considered positive, the repeated low-level detections suggest a high likelihood that the virus is present on the island. However, no confirmed cases of H5 bird flu have been found in birds, dairy cows, or humans on Kaua’i to date. Infected birds have only been reported on O’ahu. The wastewater testing cannot specify whether the detected virus is the H5N1 subtype, which has been spreading globally among birds and recently been found in mammals, including dairy cows.
Why is this a public health concern in Hawaii?
Influenza viruses undergo genetic reassortment, or change, as they spread between different animal species and humans. There is a risk that the H5N1 or other avian influenza viruses might change to spread more easily between humans, potentially leading to a pandemic. Therefore, practicing avian influenza prevention practices, monitoring for animal and human infections, and detecting any person-to-person spread early is extremely important for public health.
Monitoring for Avian Influenza in Hawaii
HDOH, in partnership with the Department of Agriculture and the Center for Disease Control and Prevention (CDC), is reinforcing long-standing efforts to detect avian influenza disease in birds, cattle, and humans in Hawaii. This includes monitoring human influenza infections detected in the laboratory, as well as in wastewater, monitoring of ED visits for influenza as tracked on the Hawaii Respiratory Disease Activity Summary dashboard, participation in the National Poultry Improvement Plan with routine sampling of chickens at the state’s largest poultry farm, USGS (United States Geological Survey) collection and testing of wild bird specimens and testing of any lactating cows being brought into the state.
Signs and Symptoms
The risk of avian influenza in Hawaii remains low for the general public. Human avian influenza symptoms are similar to those of seasonal flu. Symptoms may vary from mild to severe, and may begin with flu-like symptoms, including fever, cough, and/or sore throat. Recent human H5N1 influenza infections reported in the U.S. have been mild and included conjunctivitis.
Main symptoms (only some may be present):
- Fever
- Cough
- Sore throat
- Conjunctivitis (“pink eye”)
Secondary symptoms:
- Runny nose
- Fatigue
- Headache
- Muscle ache
- Diarrhea
- Vomiting
- Breathing difficulties
Risk in Hawaii
Although the risk of avian influenza to the general public in Hawaii from bird flu viruses is low, the following may place individuals at increased risk for H5N1 influenza virus infection:
- Close contact with sick or dead animals, including wild birds, poultry, other domesticated birds, and other wild or domesticated animals.
- Handling the feces, bedding (litter), or materials that have been touched by, or close to, birds or other animals on a farm with suspected or confirmed H5N1 influenza virus infection.
- Consuming raw, unpasteurized, milk or dairy products
Prevention
General guidance
In addition to the Hawaii Department of Health’s respiratory guidance, the following measures can reduce the risk of being infected with avian influenza.
- Do not touch sick or dead birds. Residents are encouraged to report sick or dead birds, especially when multiple or unusual. Please contact Animal Industry Division at Hawaii Department of Agriculture at 808-483-7102 during Monday to Friday from 7:45AM to 4:30PM, or 808-837-8092 during non-business hours and holidays.
- Do not drink raw milk. Pasteurization kills H5N1 virus, and pasteurized milk is safe to drink.
- When in direct or close contact (within six feet) of sick or dead animals with suspected or confirmed avian influenza, or the feces, litter, raw milk, or contaminated materials, wear Appropriate CDC-recommended personal protective equipment (PPE). Further detail is available here.
- If you become sick due to direct contact with sick or dead animals with suspected or confirmed avian influenza, isolate from family and stay home until you are proven to not have bird flu virus infection.
- Influenza antiviral chemoprophylaxis can be prescribed by health care providers to persons exposed to avian influenza. Further information can be found here.
Healthy backyard poultry practices
Keeping backyard poultry has become more popular in Hawaii as communities work to produce food locally. Adopting healthy, sustainable flock ownership practices is important to prevent illness among people and birds. The Hawaii Department of Health encourages backyard poultry owners, or those contemplating poultry ownership, to fully review CDC guidance on healthy backyard poultry practices.
Backyard poultry owners, and community members regularly surrounded by feral chickens, are encouraged to become familiar with these signs of sick poultry:
- Eat or drink less than normal
- Have ruffled feathers
- Have runny diarrhea
- Have discharge from the eyes or nose or difficulty breathing
- Produce fewer eggs than normal
- Produce discolored, irregular, or misshapen eggs
- Die unexpectedly of no apparent cause
Contact your veterinarian or the Hawaii Department of Agriculture at 808-483-7102 during Monday to Friday from 7:45AM to 4:30PM, or 808-837-8092 during non-business hours and holidays if you notice these signs.
Poultry and livestock farmers and workers
Commercial poultry and livestock farms can implement USDA and Hawaii Department of Agriculture biosecurity guidance and regulations to reduce the risk of avian influenza importation. In the event of a suspected or confirmed animal avian influenza infection on a farm, the Hawaii Department of Health recommends rapid implementation of CDC guidance to reduce the risk of human infections.
Hunters
- Do not harvest or handle wild birds that are obviously sick or found dead.
- Always wear disposable gloves when handling or cleaning game. Wash your hands with soap and water immediately afterward. If soap and water are not available, use an alcohol-based hand sanitizer.
- Dress game birds while in the field whenever possible. If you can’t dress birds in the field, clean them in a location away from poultry and other birds.
- Keep a separate pair of shoes to wear only in your game cleaning area. If this is not possible, wear rubber footwear and clean and disinfect your shoes before entering or leaving the area.
- Use dedicated tools for cleaning game, whether in the field or at home. Do not use these tools around poultry or pet birds.
- Double bag the offal and feathers. Tie the inner bag, take off your gloves, and leave them in the outer bag before tying it closed. Then wash your hands or use hand sanitizer.
- Place the bag in a trash can that poultry and pet birds cannot access. Make sure the trash can is covered, and children, pets, or other animals can’t get into it.
- Wash all tools and work surfaces with soap and water. Then, disinfect them using a freshly mixed chlorine solution consisting of 1/3 cup of household bleach per 1 gallon of water.
Handout: Hunters-Protect Your Poultry and Pet Birds from Avian Influenza (usda.gov)
Recent News
DOH Closely Monitoring Detection of H5 Avian Flu in Kaua’i Wastewater
H5 Avian Flu Detected at Wastewater Sampling Site in Hilo
DOH Notifies Public of Potential Exposure to Avian Influenza at Mililani Pet Fair Held Nov. 2
Avian Influenza Confirmed in Backyard Flock of Birds
H5 Avian Flu Detected at Wastewater Sampling Site on Oʻahu, DOH Closely Monitoring Situation
Additional Resources
Centers for Disease Control and Prevention (CDC)
Confirmed Human Case Summary Since 2024 by State and Exposure Source (cdc.gov)
Information on Bird Flu | Avian Influenza (Flu) (cdc.gov)
Prevention and Antiviral Treatment of Bird Flu Viruses in People | Avian Influenza (Flu) (cdc.gov)
Hawaii State Department of Health
Symptom Monitoring and Isolation Guidance: Exposure to Avian Influenza A – H5N1 (health.hawaii.gov)
Avian Influenza FAQs (health.hawaii.gov)
Cleaning and Disinfecting for HPAI (health.hawaii.gov)
State of Hawaii Animal Industry Division
Avian Influenza Updates (hawaii.gov)
U.S. Department of Agriculture APHIS
2022–2024 Detections of Highly Pathogenic Avian Influenza (usda.gov)
Avian Influenza | U.S. Fish & Wildlife Service (fws.gov)
Information for Clinicians
An overview of CDC’s recommendations for patient evaluation, treatment and testing can be found here. On July 19, 2024, CDC issued an Emergency Use Instructions for oseltamivir usage towards pandemic influenza A viruses and novel influenza A viruses with pandemic potential.
Disease Reporting
Highly pathogenic avian influenza (HPAI) is an URGENT CATEGORY NOTIFIABLE CONDITION. Those who were in direct contact to sick or dead animals infected with avian influenza or healthcare providers with patient(s) suspected of HPAI infection must report to the Hawaii State Department of Health by telephone as soon as a provisional diagnosis is established. Do not wait for laboratory confirmation.
Disease Reporting Lines | |
---|---|
Oahu (Disease Reporting Line) | 808-586-4586 |
Maui District Health Office | 808-984-8213 |
Kauai District Health Office | 808-241-3563 |
Big Island District Health Office (Hilo) | 808-933-0912 |
Big Island District Health Office (Kona) | 808-322-4877 |
After hours on Oahu | 808-600-3625 |
After hours on neighbor islands | 808-360-2575 (toll free) |
Last reviewed February 2025