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How is the disease spread?

AI is primarily spread by direct contact between healthy birds and infected birds, and through indirect contact with contaminated equipment and materials. The virus is excreted through the feces of infected birds and through secretions from the nose, mouth and eyes.

Contact with infected fecal material is the most common of bird-to-bird transmission. Wild ducks often introduce low pathogencicity into domestic flocks raised on range or in open flight pens through fecal contamination. Within a poultry house, transfer of the HPAI virus between birds can also occur via airborne secretions. The spread of avian influenza between poultry premises almost always follows the movement of contaminated people and equipment. AI also can be found on the outer surfaces of egg shells. Transfer of eggs is a potential means of AI transmission. Airborne transmission of virus from farm to farm is highly unlikely under usual circumstances.

HPAI can be spread from birds to people as a result of extensive direct contact with infected birds. Broad concerns about public health relate to the potential for the virus to mutate, or change into a form that could spread from person to person. The U.S. Department of Health and Human Services is aggressively working to ensure public health is protected. More information about the joint efforts of the federal government is available at

What is avian influenza?

Avian influenza (AI) is a disease found among poultry. AI viruses can infect chickens, turkeys, pheasants, quail, ducks, geese and guinea fowl as well as a wide variety of other birds, including migratory waterfowl. Each year, there is a flu season for birds just as there is for humans and, as with people, some forms of the flu are worse than others.

AI viruses can be classified into low pathogenicity and highly pathogenic forms based on the severity of the illness they cause in poultry. Most AI strains are classified as low pathogenicity avian influenza (LPAI) and cause few clinical signs in infected birds. In contrast, high pathogenicity avian influenza (HPAI) causes a severe and extremely contagious illness and death among infected birds.

Is it safe to eat lightly cooked egg dishes, or use recipes that call for raw eggs?

Today some unbroken fresh shell eggs may contain certain bacteria that can cause foodborne illness. The bacteria are Salmonella enteritidis. While the number of eggs affected is quite small, there have been some scattered outbreaks in the last few years. Currently the government, the egg industry and the scientific community are working together to solve the problem.

Researchers say that if present, the Salmonella bacteria are usually in the yolk or "yellow." But they can't rule out the bacteria being in egg whites. So everyone is advised against eating raw or undercooked egg yolks, whites or products containing them.

People with health problems, the very young, the elderly and pregnant women (the risk is to the unborn child) are particularly vulnerable to Salmonella enteritidis infections. A chronic illness weakens the immune system making the person vulnerable to foodborne illnesses.

Egg and Egg Product Safety. See also Focus On Shell Eggs.)

What is a safe internal temperature for cooking meat and poultry?

Most pathogens are destroyed between 140 and 160 °F. However, for best quality, meat and poultry require various temperatures for "doneness." A chart, listing safe internal temperatures for many foods, is part of the brochure Use A Food Thermometer, featuring Thermy™. For more information, visit the Thermy™ Web pages.

The temperatures on the chart are recommended for consumer cooking. They are not intended for processing, institutional, or foodservice preparation. Food service professionals should consult their state or local food code.

What is the safest way to thaw a frozen meat?

The USDA recommends three ways to defrost turkeys: in the refrigerator, in cold water and in the microwave. Never defrost turkey on the counter or in other locations.

  • It's best to plan ahead for slow, safe thawing in the refrigerator. Allow about 1 day for every 5 pounds of turkey to thaw in the refrigerator.
  • Turkey may be defrosted in cold water in its airtight packaging or in a leak-proof bag. Submerge the bird or cut-up parts in cold water, changing the water every 30 minutes.
  • Turkey defrosted in the microwave should be cooked immediately after thawing because some areas of the food may become warm and begin to cook during microwaving. Holding partially cooked food is not recommended because any bacteria present wouldn't have been destroyed.

If you purchase previously frozen meat, poultry or fish at a retail store, you can refreeze if it has been handled properly. 
(Source: Food Safety of Turkey... from Farm to Table. For information on thawing other items, see The Big Thaw - Safe Defrosting Methods for Consumers.

Should I use a wooden cutting board or a plastic one?

​You can choose either wood or a nonporous surface cutting board. Research shows that nonporous surfaces, such as plastic, marble, tempered glass, and pyroceramic are easier to clean than wood. Wood surfaces are considered porous. Once cutting boards become excessively worn or develop hard-to-clean grooves, you should replace them. Even plastic boards wear out over time.

How do I prevent cross-contamination (the transfer of harmful bacteria to food from other foods) when using a cutting board?

Regardless of the type of cutting board you prefer, wood or a nonporous surface, consider using one for fresh produce and a separate one for raw meat, poultry, and seafood. This will prevent bacteria on a cutting board that is used for raw meat, poultry, or seafood from cross-contaminating a food that requires no further cooking.

  • Always use a clean cutting board. Wash cutting boards with hot, soapy water after preparing each food item.
  • After washing, you may choose to sanitize the cutting boards with a solution of 1 teaspoon liquid chlorine bleach per quart of water. Flood surface with the bleach solution and allow it to stand for several minutes. Rinse with clear water and air or pat dry with clean paper towels.
  • Another good and easy way to wash the cutting board is to run it through the dishwasher after use. Non-porous acrylic, plastic, glass, and solid wood boards can be washed in a dishwasher (laminated boards may crack and split).
  • If possible, use one cutting board for fresh produce and a separate one for raw meat, poultry, and seafood.
  • Once cutting boards become excessively worn or develop hard-to-clean grooves, you should replace them. Even plastic boards wear out over time.

How do bacteria spoil food?

There are different spoilage bacteria and each reproduces at specific temperatures. Some can grow at the low temperatures in the refrigerator or freezer. Others grow well at room temperature and in the "Danger Zone." Bacteria will grow anywhere they have access to nutrients and water. Under the correct conditions, spoilage bacteria reproduce rapidly and the populations can grow very large. In some cases, they can double their numbers in as little as 30 minutes. The large number of microorganisms and their waste products cause the objectionable changes in odor, taste, and texture.

Do spoilage bacteria make people sick?

Most people would not choose to eat spoiled food. However, if they did, they probably would not get sick.

Pathogenic bacteria cause illness. They grow rapidly in the "Danger Zone" – the temperatures between 40 and 140 °F – and do not generally affect the taste, smell, or appearance of food. Food that is left too long at unsafe temperatures could be dangerous to eat, but smell and look just fine. E. coli O157:H7, Campylobacter, and Salmonella are examples of pathogenic bacteria.

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