Avian influenza

Early detection of HPAI in birds is important to stopping its spread. Infected poultry, and possibly pet birds, may show one or more of the following signs:

• Sudden death with no prior signs
• Low energy or appetite
• Purple discoloration or swelling of various body parts
• Reduced egg production, or soft-shelled/misshapen eggs
• Nasal discharge, coughing, or sneezing
• Lack of coordination
• Diarrhea

Avian influenza is most often spread by direct contact between infected birds and healthy birds. It may also be spread indirectly through contact with contaminated equipment and biological secretions and/or excretions. The avian influenza virus is found in secretions from the nares (nostrils), mouth, and eyes of infected birds and is also excreted in their droppings (excreta). Contact with contaminated droppings is the most common means of bird-to-bird transmission, although airborne secretions are another important means of transmission, especially within poultry houses. Droppings from wild ducks can introduce avian influenza into domestic flocks raised on range or in open flight pens.

Transmission between poultry facilities

The spread of avian influenza between poultry facilities almost always results from the movement of infected birds or contaminated people and equipment (including clothing, boots, and vehicles). Although more pathogenic strains of avian influenza virus can completely suppress egg production, the less pathogenic strains of the virus can be found on the inner and outer surfaces of egg shells; however, this has never resulted in hatchery transmission. Airborne transmission of avian influenza virus from farm to farm is highly unlikely because the virus cannot travel long distances through the air, and it is susceptible to the effects of sunlight and drying.

Transmission to other non-human animals

Certain mammalian species—including domestic cats and dogs—may become infected if they eat sick or dead infected birds, as might occur when outdoors in an area experiencing an outbreak. The possibility of other routes of transmission has not been ruled out. Still, the likelihood of cats and dogs catching HPAI seems low given the low number of reported cases in non-bird species, despite large outbreaks of HPAI in birds across the world.

Transmission to people

Influenza viruses that are considered to be highly pathogenic avian influenza can be spread from birds to people as a result of extensive direct contact with infected birds, such as during home slaughter or defeathering of infected poultry. Public health concerns center around the potential for the virus to mutate or combine with other influenza viruses to a form a new strain that could easily spread from person to person.

Although people may become infected through exposure to an HPAI-infected bird, this happens rarely, and typically involves infected poultry. The risk of people catching HPAI from infected cats or dogs is considered extremely low.

Animal and human health authorities worldwide monitor avian influenza viruses for their potential to infect humans. The USDA, the CDC, and the World Health Organization provide information on avian influenza affecting humans.

Numerous cases of HPAI have been reported in backyard flocks in the U.S. Although pet (possibly caged) birds are unlikely to be exposed to wild birds, the rare possibility remains that pet birds could catch HPAI, too. Biosecurity is the first line of defense against transmission of avian influenza to birds, including companion birds and commercial and backyard poultry.

Precautions for veterinarians

Owners may bring backyard birds with suspected HPAI to companion animal or mixed animal clinics. When this happens, certain precautions can help protect people and other animals:

• Take the bird to an examination or isolation room, or examine it outside the clinic.
• Perform all treatments and diagnostics there.
• Limit staff access to the bird.
• Use personal protective equipment (gown, gloves, face shield or safety goggles, and N95 respirator—or, if unavailable, surgical mask—and disposable head/hair cover).
• Practice hand hygiene after glove removal.
• Clean and disinfect contaminated surfaces.
• Disinfect items that cannot be disposed of.
• Report the case to the USDA and state authorities, who may direct you to collect samples for testing.
• Consult with state or local health officials on how to dispose of contaminated waste. Ensure that wild animals can’t access the waste.
• Recommend to the owner that the bird, and any other animals that might have had contact with it, be quarantined when returned home.

Precautions for bird owners

Owners of pet birds or backyard flocks are encouraged to stay informed about where HPAI is occurring. In regions experiencing outbreaks, certain precautions can help stop the viruses from spreading:

• Bring pet birds indoors or ensure areas where backyard birds are kept are fully enclosed, away from wild birds and their droppings.
• Wash or sanitize your hands before and after handling birds, and when moving birds between coops.
• Keep feed, drinking water, equipment, and other supplies secure, out of reach of wild birds or rodents.
• Prevent visitors from contacting your flock, and avoid visits to places where other birds are kept.
• Know the signs of HPAI, and immediately report any suspected infections to your veterinarian or state animal health official.
• Call your veterinarian first, before bringing your bird(s) in to be seen.

Additional measures

Surveillance for the influenza virus in multiple animal species, including wild birds, poultry and swine, helps detect the virus early so actions can be taken quickly to protect poultry and prevent the disease from spreading. Additionally, the U.S. Department of Agriculture (USDA), U.S. Centers for Disease Control and Prevention (CDC), and the World Health Organization work closely together to monitor both animal and human influenza viruses.