Questions and Answers On Avian Influenza ("Bird Flu")
Q. What is "bird flu?"
A. "Bird flu" is the common name for avian influenza, a respiratory disease of birds that is caused by a virus.
Q. How serious is it?
A. There are several different types of avian influenza. The milder forms occur occasionally around the world. These are known as Low Pathogenic Avian Influenza or LPAI. The more serious form is known as Highly Pathogenic Avian Influenza (HPAI) because the disease is much more severe in birds, and it results in high mortality in poultry flocks. The type now occurring in Southeast Asia is specifically called H5N1 HPAI. The designation of H5N1 comes from the arrangement of the proteins on the surface of the virus that causes the disease.
Q. Can humans get H5N1 HPAI?
A. Unfortunately, yes. A small number of people in Southeast Asia, particularly in Thailand and Vietnam, have developed a human form of the disease, nearly all of them from direct contact with live, infected poultry.
Q. How do humans get H5N1 HPAI?
A. Influenza virus lives mainly in the respiratory system and is spread through droplets of moisture. So far, with only one known, unconfirmed exception, humans have acquired H5N1 HPAI only from very close contact with infected, live birds.
Q. What are humans doing in contact with infected, live birds?
A. Chickens, ducks and other poultry in Southeast Asia are often allowed to run at large in the villages in which people live. Children and other family members tend small flocks of birds to provide eggs and meat. Nearly all of the human cases in Thailand and Vietnam are associated with these types of "village chickens."
Q. Can human infection be prevented?
A. It is apparently very easy to prevent human infection from live animals because millions of chickens, ducks and other birds have been culled by soldiers and other workers with no ill effects. There are no cases in which human infection is believed to have resulted from handling poultry meat
Q. Can humans get avian influenza from other humans?
A. It is apparently possible for a human to acquire the H5N1 HPAI virus from another human if there is extremely close contact. However, scientists say that the virus has not yet developed the ability to pass easily from human to human, and human-to-human transmission is extremely rare.
Q. How can human-to-human transmission be prevented?
A. People taking care of persons who have H5N1 HPAI should practice normal hygienic precautions. On a broader level, it is important to deny the virus the opportunity to change and evolve. This is done by stamping it out when it occurs. Both Thailand and Vietnam have aggressively destroyed poultry flocks infected with H5N1 HPAI. Experts have said that these countries should discourage the type of loose poultry husbandry that has led to the outbreaks.
Q. Can you get any type of avian influenza by eating chicken, turkey or other poultry products?
A. There is no danger of acquiring avian influenza from normally and properly cooked food. Avian influenza is caused by a virus. Like all types of viruses, avian influenza is destroyed by the heat of normal cooking.
Q. What about handling meat from an infected chicken or turkey?
A. No chickens or turkeys known or suspected to be infected with the highly pathogenic avian influenza are processed for sale as raw meat in the United States. Washing the hands after handling raw poultry is always a good precaution, but consumers in the United States have virtually no chance of encountering meat from a chicken or turkey infected with avian influenza. More importantly, the USA does not have the H5N1 HPAI and does not import poultry from the affected Asian countries.
Q. Are all types of avian influenza equally dangerous?
A. Only the H5 and H7 types are known to be able to change from the low-pathogenic form to the highly pathogenic form, so these are the types of greatest concern. Only a few specific avian influenza viruses have been shown to infect humans, and even those infections have been rare. Most of the human cases worldwide have been caused by H5N1 HPAI in Asia and H7N7 in The Netherlands. Some types of avian influenza are so mild that a blood test is needed to confirm that it is present.
Q. Do we have avian influenza in the United States?
A. We have never had an outbreak of Asian-type H5N1 highly pathogenic avian influenza in the United States, and we do not have any cases now. We had low-pathogenic avian influenza as recently as 2004. The H5N2 outbreak in one flock was designated as highly pathogenic on the basis of a laboratory test, but a more definitive test failed to confirm high pathogenicity. The last confirmed outbreak of H5N2 (not H5N1) highly pathogenic avian influenza in the United States was in Pennsylvania in 1983 and 1984. No known human illness or infections resulted from the outbreak.
Q. What happens when there is an outbreak of AI in the United States?
A. The policy of the poultry industry and the government is to eradicate the disease as quickly as possible by destroying any flocks in which the H5 or H7 types of virus are found. The animals are all destroyed and disposed of through environmentally sound methods.
Q. Why is it necessary to destroy all the birds in an infected flock?
A. Like all other living things, viruses continue to change and evolve. It is possible that the viruses that cause mild avian influenza could evolve into a more pathogenic form. This is apparently what happened in Pennsylvania in 1983 and 1984, when a low-pathogenic strain turned into a highly pathogenic strain. Flocks are destroyed to prevent the virus from evolving and spreading.
Q. What is done to protect people in the event of an outbreak?
A. The people involved in destroying flocks wear gloves, masks and protective clothing. Anyone who develops respiratory symptoms reports to a doctor to be checked out. People who have no reason to be on a farm involved in the outbreak are kept away.
Q. What is done to protect healthy animals and prevent the spread of disease?
A. Poultry companies and farmers practice strict biosecurity at all times and it is heightened during any outbreak of avian influenza. The trucks carrying feed are hosed down, personnel wear protective clothing and plastic boots and go through footbaths, farmers stay away from community gatherings, and farmers generally keep their farms locked down until the problem has passed. The eradication efforts in Virginia, Delaware and Texas in recent years resembled military operations in their scope and precision.
Q. How is Asian H5N1 highly pathogenic avian influenza being kept out of the United States?
A. The United States has multiple lines of defense against Asian H5N1 HPAI:
Transmission from live animals: The importation of birds or bird products from the affected area has been banned or placed under strict control by the U.S. government.
Transmission from poultry products: None of the affected countries in Southeast Asia are permitted to export poultry products to the United States. (Virtually all of the chicken and turkey sold in the United States is produced in the United States. The U.S. is a large poultry exporter and imports very little poultry.)
Transmission via human beings: The virus has not yet developed the ability to pass easily from human to human. If it does so, that will be considered a public health emergency and appropriate steps will be taken, presumably including restrictions on travel from the affected areas. It is possible that infected humans could bring the H5N1 highly pathogenic avian influenza from Southeast Asia to the United States. However, no one who has been to the affected areas in Southeast Asia will be allowed to set foot on a poultry farm in the United States. In addition, President Bush has taken the precaution of adding this type of avian influenza to the list of diseases for which a person can be quarantined while attempting to enter the United States.
Q. Are controls in place within the United States?
Asian H5N1 highly pathogenic avian influenza is the form of the disease that is of the greatest concern. However, other forms do exist and are considered a long-term threat to the poultry industry. The U.S. Congress has appropriated $23 million to U.S. Department of Agriculture to begin to implement a long-term, domestic avian influenza control program. The Bush administration has asked Congress to maintain that funding for 2006.
Q. Is it true that the type of intensive animal production practiced in the United States contributes to the development of avian influenza?
A. The modern type of animal production used in the United States is actually more protective of birds and their health than more traditional systems. In the United States, chickens and turkeys are usually raised in enclosed buildings called growout houses. More than 20,000 chickens or 4,000 turkeys are placed in a single building. Yet the health of the poultry flocks today is probably better than it has ever been. This is because of improvements in poultry housing, selective breeding for disease resistance, protection from potential disease carriers such as wild birds and continuous health oversight by poultry veterinarians. In contrast, the "village chickens" in Southeast Asia are raised in the traditional manner that has changed little in hundreds of years. They are fully exposed to the environment and to potential disease carriers, and they have minimal or no access to veterinary medical care.
The National Turkey Federation (NTF) is the national advocate for all segments of the turkey industry, providing services and conducting activities that increase demand for its members' products by protecting and enhancing their ability to profitably provide wholesome, high-quality, nutritious products. Its award-winning web site, www.eatturkey.com, offers consumers, food professionals and the media an extensive library of information including healthy eating and restaurant trends, turkey cuts and purchasing tips, turkey nutrition and cooking techniques, and turkey facts and trivia. Additionally, the site presents a searchable database of more than 1,500 recipes, offers a recipe E-mail program and provides special seasonal and holiday ideas. The National Turkey Federation is headquartered in Washington, D.C.