Birds and death

Q: Every day, there seems to be something in the news about bird flu. What exactly is it, and why all the fuss?

A: Bird flu, or “Avian flu,” is caused by a type of influenza virus that usually causes the flu in birds. (Yes, even birds get the flu). The reason that bird flu is getting a lot of press lately is that the virus has begun to pop up in humans, where it often causes death. Since January 2004, about 120 human cases have been reported, all in neighboring Asia. About half of them have resulted in death.

Viruses are always changing or “mutating” in order to survive. They are looking for new places to live. Sometimes a virus that usually lives in one species can mutate enough to “jump species.” This has happened with the bird flu virus. The virus can now live not only in birds, but also in humans. The good news for now is that you have to come into contact with an infected bird to catch the bird flu. You can’t catch it from another person, even if they have the virus. But, if the virus mutates further so that it can spread from one person to another person, the effects are expected to be devastating. There is no known effective treatment for bird flu, and the strain that emerged in 1997—the “H5N1” strain—is deadly for humans. If the bird flu begins to spread from person to person, estimates are that even with our best efforts, between 50 million to 150 million people will die worldwide.

The other big problem is that at first the bird flu seems like any other flu. In fact you might not even know you have bird flu. The tests to detect the bird flu virus in people just aren’t reliable. In March 2005, WHO announced that seven people in Vietnam who tested negative for bird flu at first were later found to carry the virus.

So, why don’t we just make a vaccine for the flu? Well, we can make a vaccine, but because of the way the vaccines are made, it requires at least four months to produce the vaccine, and a different vaccine must be made for any different subtype of the virus. So, while the world is gearing up and stockpiling vaccines, those vaccines may not be useful if the strain mutates further.

So far, in the current outbreak, most human cases of bird flu have been the result of eating infected poultry. In May 2005, the same virus was found in pigs in Indonesia, and is sometimes called “swine flu.” This is a really bad sign, because pigs can also carry the human flu virus. If the bird flu virus and the human flu virus get together and combine in the pigs, there is a high potential to get that form of bird flu that can spread from person to person. The pig becomes a “mixing vessel” where the bird flu virus and the human flu virus can exchange genetic material to form a new strain that can spread the deadly bird flu directly from one person to another.

This week, the virus appeared in Europe. It spread to Europe as a result of migrating wild birds, who infected poultry in Turkey (the country) and Romania. When the virus shows up in a population of poultry, it is taken very seriously, and the “cure” is to kill all the poultry to prevent further spread. You might remember that a few years ago Hong Kong killed every chicken in the territory—over 1 million birds in three days—because the virus had appeared in the poultry population there.

The transformation of the bird flu virus into a deadly virus that can be transmitted from one person to another will happen for sure. And the Angel of Death will come knocking sent by a chicken. Next week, we’ll see what can be done to minimize the effects of bird flu and the emergence of similar diseases.

(David Khorram, M.D. is a board certified ophthalmologist, and director of Marianas Eye Institute. Questions and comments are welcome. Call 235-9090 or email eye@vzpacifica.net. Copyright © 2005 David Khorram.)