Bird Flu

 

(This 793rd Buffalo Sunday News column was first published on June 11, 2006.)

 

A number of readers have asked for information about bird flu and I respond in this column, which is based largely on an essay prepared for Audubon New York by Richard Haley.

 

First, some technical information. There are three types of flu virus categorized as A, B and C. Because the B and C types cause relatively mild symptoms in humans, it is only Influenza A that is of serious concern to us. But Influenza A itself comes in 144 sub-types designated by the various forms of two protein molecules, hemagglutinin (H) and neuraminidase (N), located on their surfaces. The type we worry about now is H5N1.

 

I find another technical term about the various virus strains confusing. They are referred to as highly pathogenic or low pathogenic, that is highly lethal or less lethal. But these terms refer to how lethal they are in their normal hosts: in the case of bird flu among birds. The terms do not apply to humans in whom the effect may be very different.

 

These various virus strains develop as the result of mutations. When a life form replicates, as when humans have children, the genetic code of the parents is copied and passed on to the offspring. But sometimes the copies are not quite what would be expected. What we might consider an "error" occurs in the process, like one or more wrong keys being struck on a typewriter. Some mutations are beneficial and their long-term result is evolution. Others are bad. Human diseases like Down syndrome, Huntington's disease and cystic fibrosis are the result of such mutations.

 

Flu viruses multiply much faster than we do and there are many more of them, thus more mutations occur. What we mainly worry about today are: (1) the bird flu virus H5N1 will mutate into a form that will prove highly lethal to humans, (2) it will come to where we live, and (3) it will communicate from human to human.

 

The first problem is partially addressed by destroying flocks of domestic fowl within which the virus is detected. As to the second, no bird flu has been identified in the Western Hemisphere and scientists are monitoring wild as well as domestic waterfowl, especially in Alaska where migrating ducks and shorebirds may bring the disease from Asia. Hopefully the third problem will be addressed by the timely administration of a human H5N1 vaccine already being produced but not yet in sufficient volume. A recently developed vaccine for chickens is not yet widely used.

 

Pandemics are world-wide outbreaks of illness. There were three flu pandemics in the last century: the 1919 H1N1 "Spanish flu" strain: 50 million deaths worldwide; the 1957 H2N2 "Asian flu": 1 million; and the 1968 H3N2 "Hong Kong flu": 700,000. Although there is no current cure for any flu, many of those deaths were due to complications like pneumonia that improved health care should address. However, even our usual "mild" flu seasons lead to an average of over 30,000 annual deaths in this country alone.

 

Between January 2004 and this May, 217 cases of bird flu among humans were detected with 123 associated deaths, most in southeast Asia and almost all identified with handling of infected poultry or contaminated surfaces.

 

Some important points:

 

 

 

 

 

 

Bird flu is now a serious but distant threat. Stay tuned.

Sadly, a message from Dave Junkin informs me that Richard Haley, on whose writing for Audubon New York much of the foregoing is based, was killed in a late May automobile accident.

Among the responses to this column I received was an e-mail message from Tim Borger of Phoenix, Arizona. I take his criticisms seriously and am looking into them now. I have also responded to his communication. Meanwhile, I believe that his points are important enough to communicate them to you. Here is his message:

In your article on the bird flu you said, Hopefully, the third problem will be addressed by the timely administration of a human H5N1 vaccine already being produced but not yet in sufficient volume. This isn't correct. They can't start producing a vaccine for a pandemic strain of influenza until that particular strain has been identified. Since the virus hasn't mutated into a pandamic yet there is no way to know what the pandemic strain will look like. It's possible there might be a vaccine being produced for one of the current strains circulating in Indonesia but there is no guarantee that this vaccine will work against the new pandemic strain. They might be producing a vaccine from a currently circulating strain in the hopes that it will supply enough protection to keep people from dying. However, like I said earlier, there is no guarantee this vaccine would supply any protection against a pandemic strain of the virus.

In the Some Important Points section of the article it would have been helpful if you would have included the importance of preparing for a possible pandemic. In the event of a pandemic there is a high probablity that supply chains will be disrupted for food, medicine, etc. In fact anything you don't grow in your backyard will likely have shortages during a pandemic. Most water purification plants only keep a week's supply of chlorine in stock so storing some drinking water is also important. There are numerous websites your readers could go to for information on pandemic prepardness. One that stands out is flu wiki but there are many very good sites that give helpful information. There are also books out on the subject for people who don't have a computer.

Indonesia appears to have a human to human strain currently circulating as reported in this news story. This strain doesn't appear to be very efficient at transmitting from human to human yet but it does appear the virus is adapting to humans at an alarming rate. It looks as if it is no longer a question of Will bird flu become a human panademic? but When? Getting people to start preparing is of utmost importance."

A further message from Tim is even more threatening:

Here's some other information I found on vaccines developement for a pandemic flu.

The Congressional Budget Office provided on May 22 an excellent summary and update of the situation around vaccine production. Bottom line: With current egg-based technology, a pandemic vaccine would require at least six months to produce. Current domestic production capacity might provide enough pandemic vaccine for only about 3 percent of the population. (page 6)

The development of a quicker alternative to egg-based production is scheduled to take '60 months,' i.e. 5 years; that is, until the year 2011. (page 7)

What does "3 percent of the population" look like? The current population of the U.S. is about 300 million, of which 3 percent is 9 million. What would that much vaccine do for us?

According to the Health and Human Services Pandemic Plan (Table D-1), it would take care of: people in the military (1.5 million), people working to make more vaccine (about 40,000), and some health-care workers (8-9 million). That's it. There will be nothing for the rest of us.

Like I said previously, the pandemic will be here and gone before a vaccine is available for the general population. -- Tim