For Release October 30, 2005

Are My Feeder Birds A Health Threat?

AGRI-VIEWS
by Chuck Otte, Geary County Extension Agent

I know it's only a matter of time before someone starts asking me if the birds they are feeding at their bird feeders are a threat to give them Avian Flu. So let's have a basic class in bird flu and what threat those birds at your feeder may pose to you.

Avian influenza (Bird Flu) is an infection carried by birds around the world. The virus is carried in the intestine of the bird, often doesn't even make the bird sick, and there are many different strains of it. Bird flu can be very contagious among birds and can make some domestic birds, notably chickens, ducks and turkeys very sick and kill them. We have bird flu in the US, in fact they had an outbreak in Texas a few years ago that killed a lot of chickens. BUT, it was not the nasty strain, H5N1, that has been causing problems in other parts of the world.

The virus is usually transmitted when an infected bird sheds the virus in their saliva, nasal secretions and feces. A susceptible bird contacts these shed virus and becomes infected. The severity of the infection will depend on the particular subtype of virus (dependent on the types of proteins on the surface of the influenza virus), the health of the bird and the environment the bird is in.

The H5N1 virus is being transmitted by migrating waterfowl. In many parts of the world, these migrating waterfowl will mingle with domestic fowl thus possibly exposing the domestic fowl to the virus. Most times, an avian influenza virus is not going to infect a human. But these viruses are always changing slightly, partially because there are so many of them in any one infected individual. A basic law of genetics is that genetic changes, mutations if you will, are going to occur all the time and the more of anything you have, the more mutations will occur.

Many of these mutations are insignificant, but on occasions, this avian flu virus has mutated in a form that has allowed it to pass from a bird to a human. This has usually occurred where people live in close proximity to the infected domestic fowl or work with large fowl populations. So far, though, the H5N1 virus has not been very effective at spreading from person to person. There are a few cases where it might have gone from one person to another, but then stopped. If a mutation occurs where the virus can readily go from human to human to human, then we have a real problem. This is what happens with most of the human influenza outbreaks that we experience in this country.

Let's get back to the original question of whether the birds at my bird feeder are a threat to my health. We know that migratory birds have been spreading the disease in Asia, and probably now eastern Europe. The exact role of migratory birds is not well understood however. We do know that wild waterfowl are considered the natural reservoir for influenza A viruses (which includes the H5N1). In all reality, the birds at your feeder are a very low threat to your health. Even the waterfowl that are starting to migrate into the state are going to be a very low threat. Most of our waterfowl do not breed in the same northern regions where the Asian and European birds do. And even in the region where the outbreak has occurred, a little over 100 humans is all that has been infected.

Is there a threat to you? Sure, but it is minuscule compared to all the other health concerns we have around us, including the annual influenza onslaught that we face. So don't worry and keep feeding the birds. There is a wealth of information on Avian Influenza available at the web sites for the Center for Disease Control, http://www.cdc.gov and the World Health Organization, http://www.who.int

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