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Mayo Clinic - Bird flu fears: Why prepare now for bird flu?
Bird flu fears: Why prepare now for bird flu?
A Mayo Clinic specialist discusses timely questions about bird flu and its potential to cause a human pandemic.
No one knows if bird flu (avian influenza) will be the next crisis. But experts are worried that it could turn into a worldwide outbreak among humans ? a pandemic. Since 1997, the H5N1 bird flu strain has killed millions of birds. Hundreds of humans have become infected from birds, and more than half have died. So preparing for a pandemic is simply smart.
Here, James Steckelberg, M.D., chair of the Division of Infectious Diseases at Mayo Clinic, Rochester, Minn., answers questions about bird flu.
Is the current bird flu threat really serious?
Influenza pandemics have occurred at approximately 25- to 30-year intervals. A flu pandemic occurs when a virus mutates so drastically from previous strains that people have little natural immunity, and so large numbers of people get sick or die. Because the last pandemic took place in 1968, the thinking is that we're due for another one. And because there would be little natural immunity to H5N1, the effects could conceivably be devastating.
How long might it take for the bird flu to mutate into a serious human threat?
That's the question of the hour, and the truth is, no one knows. We do know a few important things about H5N1. First, it's particularly virulent. Second, the virus appears to be spreading among birds. Third, it seems to be affecting more species, including cats, which usually aren't susceptible to bird flu. But whether this virus will ever make the genetic changes needed to infect humans on a mass scale, or how long that might take ? there's just no way of knowing.
If bird flu were to become transmissible from human to human, how likely is it to spread rapidly worldwide?
Right now, there's no evidence of sustained, efficient, human-to-human transmission. However, if the virus mutates so that it spreads quickly among people, the great worry is modern transportation. Theoretically, infected people could board a plane and unwittingly carry the virus to the other side of the world in a matter of hours.
Who is most at risk of bird flu?
The 1918 strain was most lethal in adults in the prime of life, which means that pandemic strains may behave differently from the strains of flu that normally circulate. On the other hand, children seem very susceptible to bird flu, but that may be because they are more likely to have contact with infected birds or to play on ground contaminated with droppings. So far, people of all ages have contracted and died of bird flu.
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By Mayo Clinic Staff
Oct 2, 2006
Here, James Steckelberg, M.D., chair of the Division of Infectious Diseases at Mayo Clinic, Rochester, Minn., answers questions about bird flu.
Is the current bird flu threat really serious?
Influenza pandemics have occurred at approximately 25- to 30-year intervals. A flu pandemic occurs when a virus mutates so drastically from previous strains that people have little natural immunity, and so large numbers of people get sick or die. Because the last pandemic took place in 1968, the thinking is that we're due for another one. And because there would be little natural immunity to H5N1, the effects could conceivably be devastating.
How long might it take for the bird flu to mutate into a serious human threat?
That's the question of the hour, and the truth is, no one knows. We do know a few important things about H5N1. First, it's particularly virulent. Second, the virus appears to be spreading among birds. Third, it seems to be affecting more species, including cats, which usually aren't susceptible to bird flu. But whether this virus will ever make the genetic changes needed to infect humans on a mass scale, or how long that might take ? there's just no way of knowing.
If bird flu were to become transmissible from human to human, how likely is it to spread rapidly worldwide?
Right now, there's no evidence of sustained, efficient, human-to-human transmission. However, if the virus mutates so that it spreads quickly among people, the great worry is modern transportation. Theoretically, infected people could board a plane and unwittingly carry the virus to the other side of the world in a matter of hours.
Who is most at risk of bird flu?
The 1918 strain was most lethal in adults in the prime of life, which means that pandemic strains may behave differently from the strains of flu that normally circulate. On the other hand, children seem very susceptible to bird flu, but that may be because they are more likely to have contact with infected birds or to play on ground contaminated with droppings. So far, people of all ages have contracted and died of bird flu.
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Ask a Specialist
Centers
Web Resources
- PandemicFlu.gov, an official U.S. government Web site
- Ready America, from the U.S. Department of Homeland Security
- Centers for Disease Control and Prevention (CDC)
- Federal Emergency Management Agency (FEMA)
- World Health Organization (WHO)
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By Mayo Clinic Staff
Oct 2, 2006
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