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  • The bird flu threat: Questions and answers

    1. What's a pandemic?

    It's a global outbreak of a disease, in this case influenza. Flu pandemics have occurred when a new form of the virus appears. Unlike seasonal flu epidemics, a flu pandemic causes more illness and death because people have no natural immunity to the virus.

    2. How serious is the threat?

    Former Health and Human Services Secretary Tommy Thompson named pandemic flu and food safety the top health threats facing the U.S.

    3. How well-prepared is the government?

    Current HHS Secretary Michael Leavitt has conceded that the nation is not prepared for a pandemic--and neither is the rest of the world. Better surveillance of potential outbreaks in Asia is needed, along with more anti-viral drugs to treat the disease and faster production times for vaccines targeted to a new strain.

    4. Is there a chance of overreacting?

    No one really knows if another pandemic will hit. Even so, experts hope that precautions taken now will result in better preparedness for ordinary flu or other major disease outbreaks.

    5. What should people do to guard against it?

    They should take ordinary precautions against infection such as washing hands and covering the mouth when coughing. If a pandemic hit, officials might recommend that workers telecommute when possible in order to avoid contact with infected people. But many experts said individuals have no power to prevent a pandemic beyond demanding that governments and businesses be prepared.

    6. What is the government's plan?

    The U.S. Department of Health and Human Services is finishing an official pandemic response plan. A draft version proposed isolating infected people, closing schools in affected areas and briefly quarantining people exposed to the virus.

    7. Would quarantines work?

    A quarantine would be most useful at the original source of an outbreak, to prevent further spread. But experts say quarantines would be of limited use once a pandemic strain spread to many countries. Such measures would be intended to delay the spread of the outbreak, buying time for production of a targeted vaccine.

    8. Is there a vaccine?

    An experimental vaccine exists against the bird flu circulating in Asia, a subtype called H5N1. Although that might provide some protection against a pandemic, experts believe the disease may mutate into a form that would require a new version of the vaccine.

    9. How long would a modified vaccine take to produce?

    Once the new strain is identified, it would take about a year to produce enough doses to protect the U.S. and other countries.

    10. How many people could die if a pandemic hit?

    No one knows, in part because it's impossible to say how the virus might change. If the outbreak were as lethal as the 1918 pandemic, it could kill 180 million to 360 million people worldwide. But if the disease followed the pattern of the far less serious 1968 pandemic, the toll might be roughly equal to that of a normal flu season--about 20,000 to 40,000 deaths in the U.S.

    11. When could it hit?

    Again, no one knows for sure. Flu researchers say it's almost certain a pandemic will hit by 2025. If it struck next year, the U.S. would be poorly prepared. If it struck 10 years from now, new technologies might permit a faster response.
Jeremy: I'm going to sound like a broken record here, but the question of timing is—all together now—anyone's guess.

Anthony Fauci, director of the National Institute on Allergies and Infectious Diseases, has been quoted saying he doesn't think an outbreak will happen this year, though that may be a hunch more than anything. As CDC flu expert Martin Meltzer said in today's story, the chances that a pandemic will arise in any given year is probably low. But he thinks it's almost certain an outbreak will occur by, say, 2025.

The analogy to Hurricane Katrina is pretty good. No one knew when the Big One would hit New Orleans. But given the city's vulnerability, most experts thought it was just a matter of time. I think it's a good bet that we're in a similar predicament with pandemic flu.



Susan S., Chicago (11:49 AM): Thank you Jeremy for providing some important info.

My question is this: If the avian flu strain does mutate whereby it could pass from human to human, what type of contact would be required to infect another person?

I am a big proponent of handwashing and using antibacterial products when unable to wash my hands. Shouldn't we publicly be advocating this as well as not drinking out of other people's cups, etc.? I know it sounds like common sense but few people protect their health by doing the simple things.

Jeremy: Thanks for the reminder about handwashing, Ms. S.—it really does make sense no matter what the circumstances to reduce the risk of passing diseases.

If avian flu mutates so it can spread among people, the fear is that it would spread like normal flu - mostly via droplets transmitted in coughs and sneezes. So the precautions you mention would seem to make sense. As I said below, whether that would actually save you from getting sick during a pandemic is anyone's guess.



Mike Wean, Wilmette (11:36 AM): Is the main problem that this thing is mutating quickly, or that it spreads rapidly? Or both? Or neither?

Jeremy: Influenza mutates about as rapidly as HIV. That's why we need a new vaccine every year.

The H5N1 strain is no different. It's mutating all the time, adapting to birds and perhaps to human hosts—a perfect example of natural selection writ small. The worry is that some of those mutations will enable it to spread among people.

Once it adapts to us—if it does—then it has the potential to spread rapidly. See below, re: influenza's short incubation time.



Tom Wrona, Glen Ellyn (11:33 AM): If the virus must mutate to be passed from human to human, is it not likely that it will mutate to something that will not cause a pandemic, i.e., it will be more recognizable by our immune system than the current avian virus?

Jeremy: That's creative thinking, Mr. W. The problem is that these viruses, by their nature, contain proteins that our immune systems have never seen. They're not likely to mutate back into a more familiar form.

And remember that H5N1 isn't the only deadly avian flu strain out there. There's H7N7 and many others that could cross the species barrier, though none of the others are as widespread in birds as H5N1. All of them would be new to our immune systems, and so would pose an added danger to us.



Eric, Chicago (11:28 AM): I heard that avian flu is now in parts of Europe. Would the flu most likely continue spreading westward and first be seen in the eastern U.S.?

Jeremy: Avian flu has struck Turkey—but remember, only in birds. The risk of bird flu infecting humans in Europe and the U.S. may be less than it is in Asia. That's because, as former Jakarta resident Barack Obama said in today's story, people in Southeast Asia tend to live very close to live poultry, even in cities. That provides more chances for the virus to spread.

If the virus arrives here in birds, it may be through Alaska rather than over the Atlantic. But I don't think anyone really knows.



Dawn, Plainfield (11:25 AM): I have heard that 50 percent of the people that have gotten the bird flu have died from it. That is incredible. What is available now for people who become infected with this?

Jeremy: That 50 percent figure is right, but remember the number refers only to the percentage of known cases. No one knows how many people have been exposed to this virus and fought it off successfully without ever getting symptoms.