Highly Pathogenic Avian Influenza
Highly Pathogenic Avian Influenza
Highly Pathogenic Avian influenza (H5N1, HPAI), or bird flu, is again spreading across the United States and has been positively identified in multiple avian species in IL. There have been multiple large mortality events (greater than 5 birds) that are also suspicious for HPAI.
Learn more: IDNR, IDPH, and IDOA monitoring avian influenza mortality events in waterfowl throughout Illinois
IDNR is currently monitoring the progression of this disease process and should be contacted with any reports of 5 or more deceased or dying birds found in 1 location within a 24-hr period. To find the wildlife biologist assigned to your county, see their website.
DuPage Wildlife Conservation Center and many other rehabilitation centers in Illinois are taking actions to limit the spread of the disease, including bulking up on biosecurity measures, increased personal protection equipment, and potentially limiting high risk species intakes (waterfowl, waterbirds, raptors, scavengers). As with the last HPAI outbreak, we will use a tiered approach if cases of HPAI become exponentially worse. One of the highest levels of mitigation for this disease is halting or drastically limiting the intake of avian species, or at least species of high risk. Our highest priority is the safety of our staff, current patients, and non-releasable ambassador animals; however we still want to be able to safely provide humane euthanasia to birds suffering from suspected HPAI and treat those that are not.
At this time, we cannot take any birds from large mortality events. Again, these should be reported to and handled by IDNR. However, we will continue to admit high risk species on a case-by-case basis for now. If you have concerns about sick or injured wildlife, please give us a call at 630-942-6200. If you suspect HPAI, we highly recommend you call us first before attempting to rescue.
When handling suspicious wildlife, please wear appropriate PPE (mask, gloves, eye protection). Please disinfect any items that have come into contact with suspicious wildlife. Bleach at a rate of 1:32, which is 1/2 cup to one gallon of water, has been shown to deactivate the virus. If you do not have appropriate PPE, please do not attempt to rescue any suspicious animals.
General Recommendations
- Limit your contact with poultry and waterfowl species. Do not feed wild waterfowl and shorebird species. This not only causes the birds to congregate, increasing the chance of disease spread between individuals, it also increases their contact with humans (again, spread to humans is unlikely but still possible). Songbirds are considered low risk, so there have been no recommendations set in regard to removing bird feeders (appropriate cleaning and hygiene is still strongly recommended).
- Those with pet birds or backyard poultry flocks should keep birds housed in a building until the risk level decreases. If this is not possible (especially for poultry), house them in enclosures with fine mesh and a full roof to limit the spread of disease from wild birds.
- Be patient with wildlife rehabilitators. It’s a busy time of year and they are working under stricter biosecurity measures. Please respect that they may need to change their species or capacity limits to provide safe care to their patients and keep staff and volunteers safe.
FAQs About the Avian Flu
Avian influenza (AI), or bird flu, is a virus that primarily affects poultry and wild birds. AI viruses are often known by the combination of two different proteins: hemagglutinin (H) and neuraminidase (N).
AI also comes in two different forms: highly pathogenic avian influenza (HPAI) and low pathogenicity avian influenza (LPAI). LPAI circulates naturally in wild waterfowl and shorebird populations such as geese, ducks and gulls. These species serve as natural reservoirs and generally do not show any significant signs of disease (there are surveillance programs for LPAI in wild birds and it is routinely found). LPAI also rarely cause issues in poultry species.
However, AI can easily mutate and when the H and N proteins exchange between two or more LPAIs, HPAI can be formed. It’s similar to the human influenza virus (flu), which changes every year and requires a different vaccine. HPAI (usually H5N1, H5N2 or H5N8) are more infectious and can infect
domestic poultry species with high morbidity (sickness) and mortality (death). In this most recent 2024 outbreak, cattle, cats, and other mammalian species seem to be particularly susceptible.
Unfortunately, native wild species can also harbor HPAI and show no/minimal to severe signs. They can spread the disease via migratory flyways to commercial poultry populations over a large geographic region.
In humans, clinical signs can include mild flu-like symptoms (fever, upper respiratory signs) to severe respiratory disease or pneumonia. Infection in humans is unlikely with the H5N1 variant, however, there has been a severe case of respiratory disease identified in a patient in Louisiana recently. Those individuals with close and prolonged exposure to infected birds are at much higher risk, including those who work in wildlife rehabilitation or farm settings.
Clinical signs in wild birds include neurological deficits (seizures, tremors, ataxia, mentation changes), respiratory disease (nasal discharge, coughing), and gastrointestinal disease (diarrhea), but often are less specific (lethargy, decreased appetite).
Sudden death, especially of multiple birds, can also occur. As mentioned above, in species like waterfowl (geese, ducks) and shorebirds (including gulls), there may be no clinical signs. Raptors with HPAI are often clinical and progress rapidly within a few days. They have found HPAI in some songbirds, but they are still considered a low-risk species.
Avian influenza is shed in large concentrations in feces, but is also spread via saliva and other bodily secretions. Direct bird-to-bird spread has the highest risk of disease spread, but it can also be spread via fomites. Fomites are items that are at high risk for spreading infectious disease particles.
Almost anything that has contact with AI can serve as a fomite, making humans one of the highest risks via hands, clothing, shoes, equipment, etc.
HPAI can live weeks to months at cooler temperatures (even longer in water and below freezing), but rarely more than a few days at room temperature or warmer. It is generally easy to remove with many disinfection agents, but requires appropriate cleaning to remove any organic/inorganic material beforehand.
HPAI poses an extreme risk to the U.S. and international animal production trade. Mass outbreaks have cost billions of dollars and millions of lives in poultry and cattle species.
In the 2014-15 outbreak — considered the most significant animal health event in U.S. history — around 50 million birds died or were euthanized. The 2022-2023 outbreak was potentially even worse.