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Worldwide problem

What you should know about avian influenza

What you should know about avian influenza

April 10, 2006|by KRISTIN WILSON

In the next few months, public health officials, scientists, doctors and anyone concerned about the deadly avian influenza will have their eyes trained on Alaska.

Many officials believe North America's first case of a bird infected with the influenza A (H5N1) strain - the strain of bird flu that is causing the current outbreak - will appear this year.

Biologists and researchers in Alaska are preparing for the arrival of millions of birds fulfilling an annual migration route between Asia and Alaska.

If any one of the estimated 6 million birds arriving in Alaska by this summer carries the bird flu virus strain H5N1, it would represent the introduction of bird flu to North America.

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Since January, bird flu has spread to bird populations in African countries such as Nigeria and Cameroon. Infected wild birds have been found in Italy, Germany, Denmark and Sweden, among other western European countries.

Bird flu has dominated international headlines since 1997, when 18 human cases of bird flu were reported in Hong Kong and six people died.

Human cases of influenza A (H5N1) infection have been reported in Azerbaijan, Cambodia, China, Egypt, Indonesia, Iraq, Thailand, Turkey and Vietnam. The total number of confirmed human cases to date is 192, according to information from the World Health Organization. Of those cases, 102 have resulted in death.

Since then, more than 140 million birds have died or been killed in Asia, the Middle East and Eastern Europe in an attempt to control the virus that is spreading like wildfire among wild and domestic birds.

But those attempts have failed.

States that experience bird migration from Alaska are matter-of-fact about the progression of bird flu.

California health officials have said they expect bird flu cases to arrive in the U.S. this summer, according to a Reuters article. Information from the Oregon Department of Fish and Wildlife Web site also indicates an expectation that bird flu is coming.

It is difficult to predict if or when it would reach the Tri-State area based on this pattern.

That doesn't mean it's time to panic, health officials are quick to stress.

"People need to know that even should this virus arrive in birds in North America, the steps that our interior departments are going to take to control it will go a long way toward this having minimal impact on human health," said Thomas Skinner, a spokesman for the U.S. Centers for Disease Control and Prevention (CDC).

Scientists believe the H5N1 strain is passing from wild fowl to domestic birds. All humans who have contracted bird flu had close contact with sick or dying birds, according to information on the CDC and World Health Organization Web sites.

Avian influenza viruses are found most commonly in water birds such as ducks and geese, shorebirds and gulls. Birds such as sparrows and pigeons are not as readily infected, said Dr. Hon Ip in an October interview with National Public Radio. Dr. Ip is the director of the U.S. Geological Survey's Diagnostic Virology Laboratory at the National Wildlife Health Center in Madison, Wis.

Pet birds that are kept inside should not be at risk for catching bird flu, should the virus spread in the U.S., Ip said in the interview. There are bans against importing pet birds from regions already infected with bird flu.

There also currently is "no need" to remove chickens people keep in their backyard or on a farm because of bird flu concerns, according to the CDC Web site.

Reports of avian flu found in wild birds in the U.S. should also not pose an immediate threat to human health, Skinner said.

"There's no evidence to suggest that migratory birds are playing a large role in the transmission of this disease to humans," he explained. "By and large this continues to be a disease that is impacting birds. The people who have acquired this disease have had direct contact with sick and dying birds."

The CDC does recommend people should keep their distance from wild birds. "This protects you from possible exposure to pathogens and minimizes disturbance to the animal," according to information from the Web site.

Hunters should not handle or eat game birds that show signs of illness, according to the CDC. Rubber or disposable latex gloves should be worn when handling and cleaning game, and wild birds should be cooked thoroughly before eaten.

Unfortunately, there isn't much people can do to prepare if avian flu mutates and becomes a virus easily passed between humans.

The National Institute of Allergy and Infectious Diseases has developed a vaccine that does provide an immune response to the H5N1 strain of bird flu. However, the vaccine developed must be administered in very high doses, and even then it produced a sufficient immune response in only half of the people tested.

"They've started the process" of developing a vaccine, Skinner said. It gives some protection "but not the protection they were hoping it would offer," he added.

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