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Understanding avian influenza

Understanding avian influenza

Avian flu and humans

Avian influenza is circulating in the United States and has led to infections in domestic poultry operations. At least one two people have gotten ill, though to date, human to human transmission has not been identified. For the most current information, visit WA State Department of Health’s Avian Influenza website.

Avian flu in birds and animals

Wild birds and avian flu

Avian flu viruses have been found in many bird species, but are most common in shorebirds such as sandpipers and plovers and waterfowl such as ducks, swans, and geese. Influenza virus has been found in wild birds throughout the year, but waterfowl is the only group where it occurs year round. Birds that become infected with avian influenza viruses often show no symptoms or have only mild illnesses, but certain highly pathogenic strains can cause serious disease and death.

Migratory birds' role in spreading avian flu virus is not clear. It is known that the highly pathogenic strain of H5N1 (the form capable of causing serious illness and death) has been found in wild birds. The pattern and timing of outbreaks in domestic poultry have not necessarily coincided with periods of major migratory movements or migratory routes.

If an avian flu does come to our area it would be very unlikely, but not impossible, to catch avian flu from a wild bird. People most at risk would be those who handle sick or dead birds or hunters who process bird carcasses.

Even in the absence of avian flu, birds have other diseases that humans can catch so if you need to handle a wild bird, follow the advice for hunters.

The risk of catching avian flu to wild bird hunters is low, but the risk is higher than to a person who does not hunt. The following prevention tips apply whether or not avian flu is found in the area because other diseases can be transmitted by handling wild game birds. These tips come from the Washington State Department of Fish and Wildlife.

  • Do not harvest or handle wild birds that are obviously sick or found dead.
  • Wear rubber gloves while cleaning game or cleaning bird feeders.
  • Do not eat, drink or smoke while cleaning game.
  • Wash hands with soap and water or alcohol wipes immediately after handling game or cleaning bird feeders.
  • Wash tools and work surfaces used to clean game birds with soap and water, then disinfect with a 10 percent solution of chlorine bleach.
  • Separate raw meat, and anything it touches, from cooked or ready-to-eat foods to avoid contamination.
  • Cook game birds thoroughly. The meat should reach an internal temperature of 165º F.

Public Health does not recommend feeding wild birds in urban or suburban settings in general because bird feeders frequently attract rats or other rodents. If you do choose to feed the birds, be aware that you must regularly clean up bird droppings and spilled food, and clean bird feeders to prevent birds from spreading diseases to each other.

To protect your own health from diseases such as salmonella carried by birds, always wear rubber gloves when you touch bird droppings or clean feeders. At least once a month, submerse bird feeders in solution of 1 part bleach with 10 parts cool water for 3 minutes, rinse, and allow to air dry.

Never handle obviously sick birds and always wear rubber gloves or pick up dead birds using a shovel. With the shovel, double bag the bird in plastic and dispose in the garbage. Die-offs of multiple wild water fowl should be reported to the Washington State Department of Fish and Wildlife (WDFW) by calling 1-800-606-8768. If the bird deaths appear unusual, samples are sent to veterinary laboratories to test for diseases, including avian flu.

Bird feeding is not a risk for avian flu spread at this time and there are no regulations that would stop someone from feeding birds based on a concern about avian flu or other bird diseases. We do educate people to feed birds selectively using feeders that do not spill seeds because bird feeders often attract rats and other rodents. If rats are a problem on a property, we advise that bird feeders be removed. Visit Public Health's rodent pages to learn more.

Domestic poultry and avian flu

Symptoms of a low pathogenic form of avian flu virus in poultry can include ruffled feathers, lower feed consumption, and a drop in egg production, or there may be no symptoms at all. By contrast, the highly pathogenic H5N1 virus causes severe illness and often kills the bird within 48 hours and the first sign may be dead birds. More than 90% of birds in a flock may die from infection with highly pathogenic avian flu viruses.

To assist with surveillance for avian flu, Public Health and the Washington State Department of Agriculture (WSDA) ask that you report deaths of domestic poultry when the cause of death is unknown, and especially if several birds die at about the same time. It is not necessary to report bird deaths if the cause is trauma, such as a coyote or dog attack.

When you call, you will be asked about the circumstances of the deaths, when the birds died, and how many died. In some cases, you may be asked to hold the poultry carcasses for laboratory testing for avian flu virus. Report dead poultry to the WA State Department of Agriculture Avian Health Hotline at 1-800-606-3056.

You should wear rubber gloves or pick up dead birds using a shovel. If you are advised that the dead birds are not needed for laboratory testing, double bag in plastic bags and dispose of in the garbage. Sick birds or ones found dead should never be used for human consumption or fed to pets or other animals.

Yes. Chickens and other poultry can get avian flu from wild birds, and infection with highly pathogenic strains in domestic poultry will cause a high death rate. Waterfowl or other wild birds carrying avian flu virus may contaminate the water sources of domestic poultry, enter pens to feed on poultry food, or drop their feces into poultry houses and pens when flying over. People with backyard poultry should practice good disease prevention measures ("biosecurity").

Infected birds shed large amounts of influenza virus in their saliva, nasal secretions, and feces (droppings). In commercial egg and broiler poultry farms in the U.S., birds are generally housed in close proximity and, once introduced, avian flu viruses can spread rapidly between birds through direct contact between birds or through birds coming into contact with contaminated feed, bedding or equipment. The first sign of highly pathogenic avian influenza in a commercial chicken farm may be sudden death of a large percentage of the birds. Most poultry producers use strict infection control and biosecurity measures to reduce the risk of an avian flu virus being introduced into their flocks.

Infected birds shed large amounts of influenza virus in their saliva, nasal secretions, and feces (droppings). In commercial egg and broiler poultry farms in the U.S., birds are generally housed in close proximity and, once introduced, avian flu viruses can spread rapidly between birds through direct contact between birds or through birds coming into contact with contaminated feed, bedding or equipment. The first sign of highly pathogenic avian influenza in a commercial chicken farm may be sudden death of a large percentage of the birds. Most poultry producers use strict infection control and biosecurity measures to reduce the risk of an avian flu virus being introduced into their flocks.

Washington State Department of Agriculture officials have a response plan for controlling the spread of avian flu if it is found in domestic poultry, whether found in a large commercial flock or a few backyard birds kept as pets or for egg production. The first step would be laboratory confirmation that the virus is present. Flocks with birds infected by a highly pathogenic strain of avian influenza are to be quickly depopulated, meaning that the birds are euthanized, and the premises thoroughly disinfected. Poultry flocks within a certain distance from an infected flock may be quarantined and closely monitored for avian flu cases. Movement of people and equipment to and from affected premises may be restricted. For more information, contact the Washington State Department of Agriculture at 360-902-1800. Avian diseases (WA State Dept. Agriculture)

The owners of an infected poultry flock or any other people who had direct contact with the birds would be assessed by Public Health experts for their risk of catching avian flu virus and monitored for development of any symptoms of the disease. They and their health care provider would be given advice about the risk and any preventative measures that should be taken, such as taking antiviral medicine.

Poultry meat and eggs and avian flu

It would be extremely unlikely for chicken or other poultry you buy from the store to have avian flu. In our area, it is extremely unlikely because most birds would not get avian flu even if it were present in this region since the poultry industry generally raises its chickens and turkeys in very controlled environments. These environments, which include controlling and limiting who goes into the barns as well as special air circulation methods, minimize the chance the flock could get avian flu from a wild bird. Biosecurity measures are taken to ensure that visitors to the farm do not accidentally bring in viruses or other germs that can make birds sick. In addition, poultry is monitored closely for disease and inspected prior to being sold for human consumption.

Regardless of these biosecurity measures, poultry meat and eggs often contain salmonella, campylobacter, and other bacteria that can make people very sick so it is important to handle and cook poultry carefully now and in the future if avian flu arrives in our region. See the next question and answer for tips on how to safely prepare poultry products.

The U.S. Department of Agriculture (USDA) advises that cooking poultry to the proper temperature and preventing cross-contamination between raw and cooked food is the key to food safety. Consumers are reminded to:

  • Wash hands with warm water and soap for at least 20 seconds before and after handling food;
  • Prevent cross-contamination by keeping raw poultry, meat, and fish and their juices away from other foods;
  • After cutting raw meat, wash cutting board, knife, and countertops with hot, soapy water;
  • Sanitize cutting boards by using a solution of 1 teaspoon chlorine bleach in 1 quart of water; and
  • Use a food thermometer to ensure poultry has reached the safe internal temperature of at least 165° F to kill food borne germs that might be present, including the avian influenza virus.

For more information about avian influenza and food safety, call the USDA Meat and Poultry Hotline - 1-888-MPHotline (1-888-674-6854), TTY: 1-800 256-7072 (available in English and Spanish).

Eggs should always be properly cooked before eating. People who eat undercooked eggs run the same disease risks as eating undercooked chicken. Cooking eggs to 165º F so that the yolks are no longer runny kills disease-causing organisms, including salmonella and flu viruses.

Yes. There are confirmed human cases in Southeast Asia and other countries with outbreaks believed to have become infected during the slaughtering or subsequent handling of diseased or dead birds prior to cooking. In these countries, poultry is often raised in backyard settings and either eaten by the family or sold in live bird markets. The practices of home slaughtering, defeathering, butchering, and preparation of the meat for consumption expose people to potentially contaminated parts of poultry. A few people may also have gotten infected from consuming uncooked duck blood pudding, which is a delicacy in parts of Asia.

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