See, it's posts like this (and many of the comments that follow; hat tip to Mike) that make me worry about "bird flu." I'm more concerned about the inaccurate information and attacks on those who work in the field (and the effect this may have on public acceptance of real public health advice) than I am about the actual virus at the moment. Too many people think avian influenza is either just "media hype" or a government conspiracy (one commenter even cited the oft-refuted notion that HIV was a man-made virus. Aargh). They downplay it because it's killed relatively few people thus far, because we've known about it since 1997 and it's not become easily human-to-human transmissible yet, because of the 1976 swine flu situation, because few Asian birds make it into America, because Americans aren't in as close contact with farm animals, because predictions about other diseases have been wrong before. Thing is, we can't always rely on history to predict the future. We've learned a lot from 1976, and as described at the link above, folks who deal with influenza today are well aware of the specter of the events that happened that year. That's why we try to be careful to say that our predictions are just that--estimates based on the data available at the time. Those estimates might change as we get additional information, and we revise them accordingly. Bill Robinson seems to think this is a bad thing.
Additionally, just because it's not become HTH transmissible *yet* doesn't mean it never will. Revere over at Effect Measure has an excellent series of posts on mutations in the Turkish H5N1 strains (Part I, Part II, Part III, Part IV). As you can see, it's a complicated issue, and we don't know exactly what mutations are necessary to make one virus HTH transmissible. What we do know, however, is that several H5N1 viruses have mutations similar to ones we've seen with the 1918 strains, and others that are associated with increased virulence. It's also shown up in species which generally aren't susceptible to influenza--such as cats. It's just a strange virus, and it's killing people. Add this to the fact that it's a highly mutable RNA virus of a species that, in "normal" years kills 36,000 Americans, and I'd hope one can see that there's more to this than just Rumsfeld owning stock in Tamiflu, or Wolf Blitzer and Sanjay Gupta needing a disease crisis to talk about.
As far as the idea that we're safe because of different influenza strains in American migratory birds, or different agricultural practices--those who point to that aren't seeing the big picture. Sure, because migratory birds carrying H5N1 from Asia are less likely to make it to America than Europe, that makes us less likely for the virus to be introduced into our own poultry and cause an epidemic that way. I'll agree (provided surveillance data of those birds bears this out). The problem is, however, if a HTH transmissible strain starts to spread in Asia, or Europe, or Africa, the birds are going to be the least of our concern. While Asian birds may have a tough time getting to America, Asian travellers--or American citizens in Asia, or Europe, etc.--do not. The concern currently isn't about a de novo, highly pathogenic avian influenza virus arising in the U.S. (though theoretically, there's no reason it couldn't); it's about it being brought over here by infected humans, and spreading like wildfire through our cities. Culling birds isn't going to help us if that happens.
Anyhoo, just a bit depressing to see so much of the misinformation swallowed, and then people coming back for seconds. That just means that we have to work harder to correct it, which means more backlash due to additional stories on influenza, which means more accusations of conspiracy and "fear-based" politics...*sigh*
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According to my sources, most of the evidence so far points to Asian domestic poultry practices as being the likely source for this virus or as the source for this variant of the virus, and also as the primary route for virus movement throughout Asia (cockfighting is a particular problem for spreading the virus around). Unfortunately, domestic bird cull practices are not as effective as they could be due to non-compliance; one good cockfighting bird can sell for a large sum of money, so there is a strong motivation to hide individual chickens that are perceived to be of great value. (government reimbuirsements do not distinguish between meat chickens and cockfighting chickens).
Additionally, because governments need an easily identifable target, wild migratory birds, especially ducks, have been unfairly portrayed as the villains in the H5N1 story for years. Presumably, wild birds spread the virus as they migrate, however, this has never been documented. Current evidence suggests that, with a few very notable exceptions, wild birds are victims of this virus, rather than serving as its primary vector. In fact, until very recently, the traditional migratory routes of these wild birds, combined with the dates when they appear at any particular refueling stop, were not even similar to the dates and locations when the virus was detected in domestic poultry found in those locales.
In my opinion, culling wild migratory birds has more potential for long-term ecological damage than any other practice associated with avian influenza (witness the results from China's sparrow cull program in the late 1940s-early 1950s).
There is a possibility that wild migratory birds can reach the USA, via Siberia -- as a nearly life-long west coast birder, I can tell you that this does happen, although it is unusual. But, like you, I am far less concerned about wild Asian birds infecting wild NA birds than I am concerned about people acting as vectors for this virus.
It seems crystal clear to me that the largest danger is in the witches brew of large numbers of domestic birds in South-East Asia in close proximity to humans. Each contact is another experiment by nature, each one increasing the likelihood of the development of efficient HTH contact. Once that happens, things can spread very quickly. It only took one woman to return to Toronto from China with the SARS virus to cripple the city for months and kill about 30. Could have just as easily been Los Angeles or Chicago.
Very good points, and I think some of that goes back to what I harp on all the time anyway--better surveillance. The recent outbreaks have indeed tracked fairly well with waterfowl migration. Is this because we're watching more closely and learning about outbreaks quicker, since several previous studies haven't seen this connection? Are the older studies flawed by not learning about potential outbreaks?
Cockfighting is another issue. A world cockfighting championship was mentioned somewhere (Daily Show?) and they joked about bird flu, but it's a valid concern.
Occam's razor is probably the best way to think about most issues where human behavior is concerned. While being alert to the possibility that migration could be the primary impetus for virus distribution, there are quite a few biological reasons that underlie and support this lack of reasonable scientific evidence to suggest that wild birds have been the main vector.
Cockfighting is now thought to be the primary agent for spreading the Exotic Newcastle Disease virus around California a few years ago, even though exotic birds were incorrectly fingered as such by the poultry industry. Why can't it also play this same role throughout Asia, where it is so much more prevalent?
oops, I meant to say "there are quite a few biological reasons that underlie and support this lack of reasonable scientific evidence to suggest that wild birds have NOT been the main vector."
Hello! Long time reader, first time poster...
As I see it, your concerns are valid. This COULD be a very deadly virus. This COULD kill lots of people. This COULD spread like wildfire. However, if it doesn't, then all of the attention is just like crying "Wolf!" The next big virus that comes along will receive that much less attention. The one that ACTUALLY kills lots of people will only get a gloss over until it happens. Then you get to say "I told you so!"
Having everyone talk about it, having lots of media attention, and making everyone aware of a possible danger, are all doing you a disservice if NOTHING becomes of it. That is the real problem that we all face. How do you inform people that this could be a very deadly outbreak without making it a media storm? This is one of the problems of a global community...
Grrl,
Sure, it could play a role. I'm not as familiar, though, with the prevalence of the sport in other countries that have been affected, such as Turkey (and bird flocks in other European countries). Any idea?
Hi Douglas,
That's the question I've asked myself and others over and over, and no one can seem to find a good answer for it. I've tried to present what we know currently without "hyping" it; indeed, I've pointed out several times why H5N1 probably isn't as deadly as it's commonly reported (as a 50% mortality rate). Thing is, we're kind of in a lose-lose situation. We don't discuss the virus and it hits us, we look bad for not disseminating information. We do discuss it and it fades away, we look bad for "crying wolf." Since neither position is a great one to be in, I'd prefer to err on the side of more information, personally.
Additionally, the public has a short attention span, and often doesn't know the behind-the-scenes work that goes into fighting emerging pathogens. For example, many people think that SARS was just "crying wolf," but don't realize the work that public health officials did to contain that virus. It's the problem with public health--when it's working correctly, no one notices it.
I was about to say the same thing, Tara - if a disaster is prevented or contained it's hard to be sure if there was a real potential for the disaster in the first place, so there is a tendency to see it as having been a case of 'crying wolf' and the containment measures as overkill. And often there can be truth to that... but of course, whenever a disaster does take place everyone's happy enough to point the finger and say it should have been prevented! (The press love this, too - they get two big, juicy stories for the price of one.)
Importantly, though, the strong opitions and reactions in the press and among the public are not the critical factor. It's the public health professionals and the scientists who most need to understand the real issues: no matter how much the media bay about 'crying wolf' in the matter of SARS, for instance, I'm (almost!) sure no scientists or doctors have lost their jobs for the work they've done in containing the disease.
The principle of excellent risk communication means that you lay out the complete scenario. Risk mitigation isn't possible unless you know all the possibilities. This isn't fear-mongering. It is good risk communication.
Tara..(one commenter even cited the oft-refuted notion that HIV was a man-made virus. Aargh)...
I seem to remember a scientists who was part of a team that screwed up on the hiv virus near the congo border, apoligising for doing so.
I read it in a news paper several years back when they interviewed one of the people concerned. His comments were such that it had been released accidently...