Consider the facts about bird flu

After last week's column about gearing up for another winter of feeding wild birds, I learned that the nightly news has intersected with backyard birding. I've received quite a few e-mails and letters from readers who are concerned about the avian flu.
Lucy Hornor of Harrison County, W.Va., for example, wrote, "We enjoy watching birds all winter, but I wonder if there is any danger of the bird flu to our native bird population?"
Another e-mailer asked if there was any danger of contracting avian flu from birds at bird feeders.
In light of the daily barrage of news about the avian flu and the seemingly inevitable pandemic, these are prudent questions. The information that follows comes from the Centers for Disease Control and Prevention (www.cdc.gov/flu).
What it is
Avian influenza or bird flu is a contagious disease caused by viruses that naturally occur in the intestines of birds. There are many subtypes of the virus and most are relatively harmless to their carriers. Some, however, are deadly. The H5N1 virus that is currently a problem in Asia is a particularly virulent form.
H5N1 virus spreads from bird to bird via saliva, nasal secretions and feces. Because they live in close quarters and often in unsanitary conditions, domestic fowl (chickens, turkeys, ducks and geese) are particularly susceptible to this virus. It spread rapidly in late 2003 and early 2004 in Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand and Vietnam. During that time more than 100 million birds in those countries died or were killed to control the outbreak. Another outbreak, which continues today, occurred in June 2004.
The H5N1 virus doesn't normally infect people, but the first human cases were detected in 1997 in Hong Kong. These cases resulted from contact with infected birds or contaminated surfaces -- conditions vendors butchering birds in open-air markets might encounter.
The concern of health officials worldwide is that the H5N1 virus could mutate into a form capable of spreading from human to human. Because these viruses do not normally infect humans, we have little or no natural immunity to them. If H5N1 mutates to a people-to-people form, an influenza pandemic could begin. (A pandemic is a worldwide outbreak of disease.)
In today's global economy, where travelers can get halfway around the world in a day, a single infected person with no symptoms could travel from Asia to Chicago, sneeze a few times, shake a few hands, and infect a plane full of passengers. It's a scene right out of a disaster movie. If this happens, millions of people could die in days.
Watching it
The good news is that world health officials are watching the H5N1 situation in Asia closely. Though no vaccines for this flu currently exist, a race to develop them has begun. If humanity is lucky, it will take a few years for the human-to-human form of the virus to develop, and in that time an effective vaccine may be developed.
The CDC advises, "The current risk to Americans from the H5N1 bird flu outbreak in Asia is low. The strain of H5N1 virus found in Asia has not been found in the United States."
One real fear is that wild birds could pick up the H5N1 virus from domestic birds and spread it during migration. Asian species that migrate north to the Bering Sea often jump to Alaska. From there North American migrants could pick up the virus and carry it south. I suspect the health of migrating arctic waterfowl and shorebirds will be monitored carefully over the next few years.
For now, there is no risk of bird flu at backyard feeders. And even if wild birds were infected, it couldn't pass to people unless feeder birds were captured, butchered and carelessly handled. And the thought of that is, of course, ridiculous.
So fill your feeders, and enjoy the birds. If the bird flu becomes dangerous to people, it will be the news story of the century.
XSend questions and comments to Dr. Scott Shalaway, R.D. 5, Cameron, W.Va. 26033 or via e-mail to sshalaway@aol.com