Bird flu: prepare but don't overreact

March 20, 2006

CORVALLIS, Ore. – Oregonians who raise chickens or other domestic fowl around their homes should think about precautionary steps they could take if a virulent strain of avian influenza, or bird flu, is detected in Oregon.

But it's too early for action, an Oregon State University Extension Service poultry science specialist believes.

"Right now I would do nothing," said Jim Hermes, who works with the state's commercial poultry industry and with backyard growers.

"Even if there is an outbreak, don't panic," Hermes said. "Simply figure out how you'd isolate your birds from wild birds that might be a source of the flu virus. You might have to add fencing or put them in a coop until we get a handle on things. This is a process the poultry industry has been using for several years, called 'biosecurity.'

"One question I'm getting a great deal is 'where can I get a vaccine for my chickens?' There aren't any in use in the United States at this time, except for experimental ones. They're vaccinating commercial flocks is Asia with some success, but the virus mutates and it's hard for vaccines to keep up."

Hermes noted that bird flu is not new to the United States.

"We've not had the avian influenza in Oregon in recent years, but we have had outbreaks of the low-path [less virulent] form in California in recent decades," he said. "They had a high-path [highly virulent] outbreak on the East Coast in the 1980s, and they found a high-path strain in British Columbia a few years ago and had to destroy millions of chickens."

The professor in OSU's College of Agricultural Sciences said he is more concerned about the threat to backyard poultry than to Oregon's relatively small commercial poultry industry.

"Commercial operators know how to protect their birds by practicing strict biosecurity programs," he said, explaining that most commercial chickens are kept in enclosed facilities where there is little chance of contact with wild birds or other possible sources of infection.

Oregon has three major egg-producing farms with a total of about 3 million laying hens, said Hermes, and there are "40 to 45" broiler farms in the Willamette Valley in an area that runs roughly from Lane County to Clackamas County.

Concerns about avian influenza go beyond the danger it poses for domestic and wild animals. In Asia, Eastern Europe and Africa a virulent form has spread to humans, raising fears of an epidemic.

According to PandemicFlu.gov, a website operated by the U.S. Department of Health and Human Services, there is confusion about the viruses that cause various types of flu. The website offers the following explanation:

"Seasonal (or common) flu is a respiratory illness that can be transmitted person to person. Most people have some immunity, and a vaccine is available.

"Avian flu is caused by influenza viruses that occur naturally among wild birds. A variant called H5N1 is deadly to domestic fowl and can be transmitted from birds to humans. There is no human immunity and no vaccine is available.

"Pandemic flu is virulent human flu that causes a global outbreak, or pandemic, of serious illness. Because there is little natural immunity, the disease can spread easily from person to person. Currently, there is no pandemic flu."

OSU's Hermes noted that "bird flu is not something humans can contract from eggs and chickens if you follow standard food safety procedures such as washing your hands, avoiding cross contamination in food preparation, and cooking food so that it reaches a temperature of 165 degrees Fahrenheit."

There are no known cases where H5N1 has been transmitted from wild birds to humans, according to the PandemicFlu.gov website. However, the federal government, in cooperation with state and local officials, plans to step up surveillance of migratory birds to determine if any of them carry the H5N1 virus.

A key focus of the increased surveillance will be the state of Alaska, which sits at the northern end of the Pacific Flyway that runs from Baja to Alaska. The Pacific Flyway is a kind of "biopolitical region" used to manage migratory game birds such as ducks, geese, swans and cranes, according to Bruce Dugger, a waterfowl ecologist in OSU's College of Agricultural Sciences. The flyway includes U.S. states and Canadian provinces west of the Rocky Mountains.

Some migratory birds breed in Asia and move from there to Alaska, Dugger said. In the fall, large numbers and various species of waterfowl will migrate south down the Pacific Flyway from Alaska to Oregon and beyond.

Author: Andy Duncan
Source: Jim Hermes, Bruce Dugger