Cooperative Extension Publications

By Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

Reviewed by Beth Calder, Extension Food Science Specialist and Professor of Food Science and by Michele Walsh DVM and Carolyn Hurwitz DVM, Maine Department of Agriculture, Conservation and Forestry

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What is Avian Influenza?

Avian Influenza (AI) is a contagious type A influenza (“flu”) virus of birds that occurs worldwide and is not uncommon in wild birds of many types. Some strains of AI can mutate and are capable of affecting other animal species and occasionally people.

Is Avian Influenza (AI) a threat to Maine?

A strain of highly pathogenic Avian Influenza (HPAI) has been found in the Northeast United States and Canada during 2022 in wild birds (primarily waterfowl). Since late February 2022, there have been multiple detections of HPAI in North America in both backyard and commercial birds, including backyard birds in Maine. This situation is changing rapidly. PLEASE CHECK THE USDA WEBSITE FOR UPDATES AND MORE INFORMATION.

What kinds of Avian Influenza are there?

There are many types of AI, but in general, we refer to them as low (LPAI) or highly pathogenic (HPAI) AI. Although LPAI typically causes less severe disease than does HPAI, certain types of LPAI (H5 and H7 viruses) are likely to mutate as they infect new hosts. These changes may create a more pathogenic strain (HPAI), so even LPAI is of concern. HPAI can cause serious disease and/or rapid death in susceptible birds. Avian influenza is described by specific types of proteins: the hemagglutinin (H) type, and the neuraminidase (N) type. If a strain of AI has either the H5 or H7 type of protein, it’s considered HPAI and is watched carefully. If HPAI is found, it must be reported to the state and USDA regional veterinarians, who then respond to contain the spread of this disease.

How is Avian Influenza spread?

As a flu virus, AI replicates in the respiratory and gastrointestinal tracts, so it is spread via respiratory droplets, saliva, mucus, and manure. It may also be capable of airborne spread if conditions allow (for instance, when very high amounts of virus are being produced). Contaminated surfaces, feed, water, environments, and items such as tools or workers’ boots can also spread the disease. Influenza viruses can survive for extended periods of time in cool, moist environments like wet bedding, manure, and mud. Regular sanitation and disinfection practices can help prevent spread of AI via this route.

Can people get Avian Influenza?

Some strains of AI can be transmissible to people. The strain of H5N1 currently seen in the Northeast does not at this time seem to spread to people. However, because influenza viruses can mutate to become more pathogenic, it’s still necessary to take protective measures to prevent human exposure to this virus. Wear PPE such as disposable gloves and wash your hands after handling sick or dead birds. Public health agencies continually monitor for avian influenza viruses and you can find more information about human health risks (including guidance on poultry meat and eggs) at Information on Avian Influenza.

In general, never eat birds that appear sick, and always prepare poultry following the USDA preparation and cooking guidelines (cooking to an internal temperature of 165°F or higher).

Can other animals get Avian Influenza?

Rarely, animals such as marine mammals, farmed mink, ferrets, dogs, and cats have been reported to be susceptible to some strains of AI. Swine are susceptible to both human and avian flu, creating a possibility of mutated flu that might put people more at risk. Co-housing pigs and poultry is not encouraged due to this risk.

As a small flock owner, how would I know if my birds have Avian Influenza?

AI is something to keep in mind, should you notice respiratory disease in birds, but it’s not the only cause of respiratory symptoms or diarrhea in birds. There are several forms of influenza (AI) that can affect poultry: relatively non-pathogenic (low path AI; LPAI) and the more dangerous form (high path AI; HPAI). If you see severe illness and sudden death losses in your flock, you should call the regional USDA hotline: 866.536.7593, and also let your farm vet know. If your flock is experiencing losses, but you doubt that they are due to HPAI, then you should have a necropsy conducted; the University of Maine Veterinary Diagnostic Laboratory can assist farmers in our region. As well, now is a great time to review your poultry management to ensure the safety of your birds; we call this biosecurity.

What is biosecurity?

Good biosecurity keeps germs away from chickens, and enhances their natural immunity via good nutrition, hygiene, and environment. A balanced diet and plentiful water, good fencing, clean coops/hen houses, hand washing/boot cleaning before and after handling birds, and quarantine for new or re-entering birds to a flock are examples of biosecurity for any flock. For instance, Mexico’s poultry industry has been severely affected by AI since 2012, and some potential factors for the recurrent outbreaks of AI include:

• General lack of biosecurity: AI was detected at broiler breeder farms, which should have had the highest standards for biosecurity. It takes constant vigilance to keep a farm free of wild birds, rodents, or dirty boots from visitors.
• Selling infected poultry litter to fruit and vegetable growers: poultry producers need to be sure that they are not spreading disease. Used poultry litter must be effectively composted, disinfected or buried. In the case of some diseases, like parasites or salmonella, composting is not a reliable means of disinfection. Litter can be a source of repeated AI outbreaks.
• Selling live “spent” hens. Sometimes these birds are “recycled” by molting and then keeping them for another egg-laying cycle. This practice can perpetuate a disease problem.

If you would like to know more about biosecurity practices, please visit the USDA website.

How can I stay updated on Avian Influenza and where it is a problem?

If you would like to see an up-to-date review of AI in the US, go to the CDC site. To see where HPAI has been detected in our region, go to this USDA site.

The Maine Department of Agriculture, Conservation and Forestry (DACF) provides situation updates focused on the local response on their News page. The link to access these reports and option to sign up to receive email announcements is here. If your farm lies within a “control zone” where AI has been detected, the state response team will reach out to you with more information.

What can I do to protect my birds from Avian Influenza?

Great biosecurity is the best protection. Important steps are listed below, and you can learn more at the USDA Defend the Flock Program website.

• Be careful to house your birds where other birds — especially wild birds — don’t have easy access.
• Use a small size mesh (“hardware cloth”) to keep small wild birds from visiting your poultry. Include a “roof” that will keep wild bird feces out of the coop.
• Place feed and water containers where they don’t “tempt” wild birds. For instance, place containers inside a structure or away from the borders of the coop.
• If you free-range your flock, this would be a great time to transition them to indoors, or within a controllable space with a cover to keep wild bird feces out.
• If you still free-range, don’t let your birds gather around wild bird feeders or ponds. It is not recommended to have wild bird feeders if you have backyard poultry.
• Try to keep wild ducks, geese, and turkeys away from your poultry: use double fencing for your perimeters (birds can reach through a single fence) and create a “roof” for your coop (wild turkeys can and do fly).
• Don’t use poultry litter on your land unless it’s been well-composted.

Are there Avian Influenza vaccines for birds?

In outbreak situations, the USDA APHIS may allow AI vaccination under strict control. However, this is unlikely. Please check with the USDA site (above) for more information. Your state veterinarian will know if this option becomes available.

What about other farm animals — can they get Avian Influenza?

In general, flu viruses have a way of “jumping” between certain species: notably humans, birds, and pigs. While this is not a common event, it’s still important to be aware of this possibility. For this reason, it’s important to avoid mixing poultry and swine. It’s also very important to isolate sick pigs from poultry or people, and to avoid visiting livestock fairs or farms if you have a cold or the flu.

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Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

© 2015, 2022

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