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. KansasStateUniversity 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