Bird Flu and You 5/5/06

MANHATTAN, Kan. – Scientists worldwide are studying a new and still emerging avian – or bird – flu. To date, news reports number into the hundreds of thousands, but speculation about the new flu and when, where and whom it may strike is simply that – speculation.

Poultry Specialist Answers Questions About Bird Flu

MANHATTAN, Kan. – Flu season – December to March – is months away, yet bird flu is in the news. While the interest might seem unseasonable, predictions of a possible flu epidemic are reason for concern. Separating fact from fiction isn’t always easy. Kansas State University poultry specialist Scott Beyer answered frequently-asked questions about the new bird flu:

Q: What is avian – or bird – influenza?

A: Avian influenza, also called bird flu, is a viral respiratory disease that typically afflicts birds.

Q: Why is avian influenza in the news?

A: A current outbreak of avian influenza in Southeast Asia and in Europe is a more severe form of the virus than scientists usually see. It can spread rapidly through poultry flocks.

Like other viruses, avian influenza viruses have proteins on their surface that an infected animal may recognize as foreign and respond to by synthesizing antibodies to neutralize the virus. The current virus, the H5N1 strain, is worrisome because it has rearranged these proteins in a manner that is new to the bird’s immune system, which is less able to fight a viral infection it doesn’t recognize.

Q: How is avian influenza transmitted?

A: The virus is typically passed from one bird to another. Open-air markets in Southeast Asia in which live birds from many small flocks may be sold, create an environment in which the disease can spread from one bird to another and from one flock to another easily.

Q: If this flu is for the birds, why should I worry?

A: While most forms of avian influenza affect poultry and not humans, the H5N1 strain has infected humans. Scientists fear that the virus could change (mutate) in such a way that it would become more infective to humans and transferable from human to human.

Q: Isn’t there a flu shot that can provide immunity to avian influenza?

A: Flu vaccines typically contain combinations of Influenza A forms H1N1, H1N2 and H3N2 and Influenza B. The Influenza A viruses originated from birds decades ago and have adapted so that they are easily transmitted from human to human. To create a flu shot vaccine that will provide immunity to these viruses each year, public health officials try to anticipate how these viruses will make small changes in order to sidestep the human immune system and formulate the annual vaccine accordingly.

The new form of avian influenza -- H5N1 -- is a major recombination of the Influenza A viruses that the human immune system is not primed to recognize or defend against. Such viruses mutate spontaneously and, while the virus is currently infecting poultry, scientists are concerned that the virus could mutate, become more infectious to humans and spread more rapidly.

Q: Can bird flu spread from Southeast Asia to the United States?

A: At present, the virus appears to be isolated in Southeast Asia and Europe. A small outbreak in Romania and Turkey indicates that it could be spreading and scientists fear transmission through wild birds or people who are transporting poultry to other parts of the world.

The fact that the United States exports, rather than imports poultry, lessens the current risk. In the U.S., larger commercial poultry producers house commercial flocks, so contact with wild birds that could pass along the virus is unlikely. In the U.S., commercial poultry also is processed before it is marketed, and not sold live.

As an additional safeguard, anyone who has visited contaminated areas of the world is not allowed to return to a poultry farm in the U.S.

Q: Does this mean that avian influenza is not a serious threat in the United States?

A: Scientists are concerned and continue to monitor avian influenza. No one can say for sure if – or when – the disease will strike in the United States.

Such viruses mutate spontaneously and that is why the U.S. poultry industry does not allow any form of the virus. U.S. poultry producers work to eradicate any disease as quickly as possible and their disease prevention strategy reduces opportunities for the virus to evolve into a more pathogenic form.

Scientists report that the virus has not yet acquired the ability to move easily from human to human, but around the world, about 116 people who have directly handled infected flocks have been diagnosed with avian influenza (H5N1).

People who have live poultry – a flock or smaller, hobby flock – should consider biosecurity. The virus can be transmitted in manure, on clothing or shoes and during traffic from one farm to another. Exposure to other birds at swaps, trades or shows could be a threat.

If visiting a poultry show, shower and change clothing and shoes before contact with your birds. Keep potentially contaminated clothing and shoes separate and wash clothing and disinfect shoes promptly. If buying new birds, have the birds tested for avian influenza first.

Q: Can wild or migratory birds, such as waterfowl, carry the disease?

A: Yes, migratory birds can carry the virus. Such birds are being tested and routinely screened. While the virus has not yet been detected in wild birds in North America, I recommend eliminating the opportunity for small flocks to interact with wild or migratory birds by placing netting over poultry pens or yards and eliminating feed waste that may attract them.

We also recommend moving poultry away from open ponds, which are attractive to migratory birds that may, at some time, carry the virus. Eliminating the pond also may be an option, as it does increase risks.

Q: Is it possible to contract avian influenza from eating chicken?

A: No. If the virus were present, heat from normal cooking would kill it.

Source: Scott Beyer, Kansas State University Research and Extension poultry specialist

An upcoming, made-for-television movie, “Fatal Contact: Bird Flu in America,” set to air on ABC May 9 is, however, expected to spark still more interest in the new flu virus. To help separate fact from fiction, Scott Beyer, Kansas State University Research and Extension poultry specialist answered frequently asked questions about the new flu:

A: The new strain of bird flu is transmitted primarily between bird species. There are some cases in Asia and Europe in which the virus has passed from an infected bird to a person who has been in close contact with that bird, but researchers believe that the virus will have to mutate (a process in which genes rearrange themselves) several times and perhaps in a series or in a cascade of mutations before it becomes a health risk for the human population.

Q: Does that mean that the general population can ignore the prospect of new bird flu?

A: No. When a virus is new, the general population will not yet have had an opportunity to develop a natural immunity to it and scientists also will not have had the time to formulate a vaccine effective in fighting the virus. That means that normally healthy people may face increased risks from the virus. People who are immuno-compromised such as the elderly, people who are suffering from a chronic illness or children, whose immune systems are not yet fully developed, may face even greater risks.

A: Be aware. Keep up on the news and when – and if – the virus should mutate in such a way that it becomes a health threat to the general human population, use common sense: Practice good hygiene; wash your hands frequently; get plenty of rest; eat a variety of foods; stay hydrated and away from crowds.

Q: If the flu is spread by poultry, what is the poultry industry doing to protect its flocks to keep the flu from spreading?

A: In the United States, the poultry industry has dealt with poultry viruses for years, but not this particular strain. The industry has been vigilant in testing since the 1970s. If pathological reports, blood tests, swabbing facilities and even testing farm cats and dogs near a poultry facility indicate the presence of any poultry virus, the flock is destroyed, the farm emptied and sanitized.

Poultry production techniques do, however, vary worldwide. In many places, including the Far East where the new bird flu was first identified, poultry often is raised in small, independent flocks and sold at open-air markets allowing an opportunity for infected birds to infect other flocks.

A. In the United States, a vigilant monitoring system keeps infected birds from entering the consumer food supply. Cooking poultry to the recommended internal temperature – 160 F – will kill the virus. Eggs also are safe. If a laying hen is infected with the virus, the hen will stop laying (eggs). Also, if for some reason, an egg is infected with the virus, cooking the egg to 160 F will kill the virus.

A: That’s a worry, and the reason scientists are studying the birds in their current habitat and expected migratory flyways with the hope of reducing the spread of the virus. That also is why farmers are being encouraged to discourage migratory bird contact with their flocks and with their farms in general. For example, a farmer may want to allow corn stalks to stand to discourage migratory geese that need a clear field for landing.

The study of migratory birds, including ducks and geese, is ongoing, and keeping up on the news is advisable, as Kansas is a flyway for migratory birds.

K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.