Wednesday, October 26, 2005
Bird Flu - A Sobering Look At Non-Asian Events
The press coverage of bird flu lately has been sensationalist and not particularly informative.
Basically the risks split into two categories. The first is that wild birds are carrying a very pathogenic strain of H5N1 into Europe and now down into the ME and Africa. There this strain too will become endemic and will tend to affect poultry. Eventually this strain will arrive in the Americas, either from migrating birds or from an imported bird. The new outbreaks in places like China, Thailand and perhaps Indonesia show that the Qinghai strain is crossing back down through Asia. H5N1 will do great damage to poultry producers and inflict large economic losses. Russia has done everything it can to stamp out outbreaks but is losing the battle and new outbreaks are being reported in China almost every day.
The second is this spreading of H5N1 offers new possibilities for the virus to recombine with other strains and pick up bits of genetic information that make it very good at infecting humans, thus producing a human to human strain. The strain of bird flu designated H9N2 in Israel and the surrounding countries have matches that could produce precisely this result. See Dr. Niman's commentary:
So, the summary is basically this. First, in less than a month Europe's belief that it was not facing a significant threat from this virus has been rudely disrupted. Second, the vector of the virus is headed into large swaths of territory involving poorer countries and far more vulnerable people. Third, the virus will go human to human sooner or later. It is too virulent and infects too many mammals for that not to happen. Fourth, for that to happen would not require a grand leap of mutation - it could easily happen as a very normal and expected consequence of cross-infection in birds.
As for where the virus has been reported or bird-dieoffs have been reported, see Dr. Niman's map. The squares are unconfirmed suspect dead birds; the circles are confirmed cases. Both Iran and Yemen have denied bird die-offs as a result of the virus. I don't think most people find that credible:
Basically the risks split into two categories. The first is that wild birds are carrying a very pathogenic strain of H5N1 into Europe and now down into the ME and Africa. There this strain too will become endemic and will tend to affect poultry. Eventually this strain will arrive in the Americas, either from migrating birds or from an imported bird. The new outbreaks in places like China, Thailand and perhaps Indonesia show that the Qinghai strain is crossing back down through Asia. H5N1 will do great damage to poultry producers and inflict large economic losses. Russia has done everything it can to stamp out outbreaks but is losing the battle and new outbreaks are being reported in China almost every day.
The second is this spreading of H5N1 offers new possibilities for the virus to recombine with other strains and pick up bits of genetic information that make it very good at infecting humans, thus producing a human to human strain. The strain of bird flu designated H9N2 in Israel and the surrounding countries have matches that could produce precisely this result. See Dr. Niman's commentary:
A search of the Los Alamos flu database using a 10 nucleotide probe representing the S227N polymorphism identified 42 exact matches. All were in HA and all isolated after 1998 were in the Middle East in chickens, turkeys, geese, and an ostrich.Birds that might carry this strain would travel further south into Africa. The Gulf States are aware of the danger and have instituted measures, some draconian, to try to stop H5N1 from moving into their poultry. But they can't stop the virus from infecting wild birds, so.... For a more detailed explanation of the potential for recombination and acquisition of the S227N polymorphism, see this CurEvents.com thread.
H9N2 has become endemic in Israel and millions of migratory birds will be passing through the area in the upcoming days. Thus, the potential for dual infections by H9N2 and H5N1 is high. The 10 nucleotides of identity offers an opportunity for homologous recombination that would create the S227N polymorphism and increase the efficiency of H5N1 human transmission.
Efforts to limit the exposure of H9N2 infected birds to H5N1 infected wild birds should be aggressively pursued.
So, the summary is basically this. First, in less than a month Europe's belief that it was not facing a significant threat from this virus has been rudely disrupted. Second, the vector of the virus is headed into large swaths of territory involving poorer countries and far more vulnerable people. Third, the virus will go human to human sooner or later. It is too virulent and infects too many mammals for that not to happen. Fourth, for that to happen would not require a grand leap of mutation - it could easily happen as a very normal and expected consequence of cross-infection in birds.
As for where the virus has been reported or bird-dieoffs have been reported, see Dr. Niman's map. The squares are unconfirmed suspect dead birds; the circles are confirmed cases. Both Iran and Yemen have denied bird die-offs as a result of the virus. I don't think most people find that credible:
Comments:
<< Home
No one denies that we are facing a real problem.
That said, there is no upside for these second and third world countries to manipulate the data, re the Bird Flu. If anything, their credibility would improve with honest reporting.
In addition, there needs to be a uniform protocol in diagnosing and reporting of health threats. Right now, it's a free for all.
That said, there is no upside for these second and third world countries to manipulate the data, re the Bird Flu. If anything, their credibility would improve with honest reporting.
In addition, there needs to be a uniform protocol in diagnosing and reporting of health threats. Right now, it's a free for all.
It is a free for all.
China seems to be getting better.
However, I think half the problem is that this is a new disease and it's always hard to get geared up for new diseases.
For all we know there could already be a couple new variant strains out there. Given what is happening in Thailand and Indonesia, there well may be.
As for noone denying that there is a real problem, the rumor flying through the ME is that this is "Bush's virus". One version says that the US is deliberately spreading the disease, and the other that the entire threat is not real at all. There have been Russian complaints that this is all a US ploy to destroy their poultry industry for our own benefit.
Post a Comment
China seems to be getting better.
However, I think half the problem is that this is a new disease and it's always hard to get geared up for new diseases.
For all we know there could already be a couple new variant strains out there. Given what is happening in Thailand and Indonesia, there well may be.
As for noone denying that there is a real problem, the rumor flying through the ME is that this is "Bush's virus". One version says that the US is deliberately spreading the disease, and the other that the entire threat is not real at all. There have been Russian complaints that this is all a US ploy to destroy their poultry industry for our own benefit.
<< Home