LAT: Bird Flu Defies Control Efforts

[DeepModem Mom]

Bird Flu Defies Control Efforts
The culling of flocks has failed to slow the rapid spread of the virus, due in North America this year. Vaccination of poultry is under study.
By Jia-Rui Chong, Times Staff Writer
March 27, 2006

The spread of avian influenza to at least 29 new countries in the last seven weeks — one of the biggest outbreaks of the virus since it emerged nine years ago — is prompting a sobering reassessment of the strategy that has guided efforts to contain the disease.

Since February, the virus has cut a wide swath across the globe, felling tens of thousands of birds in Nigeria, Israel, India, Sweden and elsewhere. Health officials in the United States say bird flu is likely to arrive in North America this year, carried by wild birds migrating thousands of miles to their summer breeding grounds.

The speed of its migration, and the vast area it has infected, has forced scientists to concede there is little that can be done to stop its spread across the globe.

"We expected it to move, but not any of us thought it would move quite like this," said Dr. David Nabarro, the United Nations' coordinator on bird flu efforts.

The hope was once that culling millions of chickens and ducks would contain or even eradicate the virus. Now, the strategy has shifted toward managing a disease that will probably be everywhere. Officials are hoping to buy a little more time to produce human vaccines and limit the potential economic damage....

http://www.latimes.com/news/science/la-sci-birdflu27mar27,0,1298190.story?coll=la-home-headlines

[Warpy]

1. Research is showing that what makes it so deadly to humans

is also what's preventing it from being an efficient pathogen. It tends to lodge far down in the lungs before it can do any damage, while efficient bugs tend to lodge in the nose and upper respiratory system where it can easily be coughed out and spread quickly via droplet to anyone in the area.

There may be a tradeoff at work here. If it modifies to become an efficiently spread bug, it'll have to change its attack site, and that means it will be far less deadly, probably on the order of the 1918 flu instead of the 50%+ killer it is now.

They need to discover how it spreads among birds, though. Culling domestic flocks is not going to work because the reservoir is in the wild bird population.

[pinto]

3. Great concise overview. I assume droppings from wild birds is the

vector to domestic poultry populations. Doubt if there's a feasible poultry vaccine, but that would be the obvious snip to make in transmission.

I'd support broad scale poultry vaccination - if it was available and doable. Culling infected flocks seems to be the only day to day approach right now, though.

Thanks for the post.

[SaveElmer]

7. No evidence I know of for the droppings theory...

In fact what I have seen is that many now think it is the other way around. Poultry began infecting wild birds.

Vietnam did a countrywide cull followed by vaccination. They have not had an outbreak since November.

[pinto]

8. Did they find the vaccination effective? or was the cull the cure,

so to speak?

Re: transmission, I meant the current, out of Asia, spread. Wild bird migration seems to be the logical vector. I assumed droppings would be the carrier to outdoor domestic flocks. (on edit) Unless they share watering holes or some other close contact scenario...?

[SaveElmer]

10. Well I'm just not sure...

So far in Western Europe only one farm has been hit - in France. They initially belived it was droppings, but now believe the virus got in by another method...possibly on the clothes of someone, or by another animal. As to the other affected farms the jury is still out, but the pattern is kind of suspicious. Nigeria has widespread infection but countries to t he north do not. ANd no dead wild birds have been found there. I think the larger danger is in poultry trade and smuggling.

My understanding is that these vaccines are effective in Birds. The reason some are hesitant to use them is they could mask the presence of infection in flocks.

[pinto]

11. Thanks.

[madeline_con]

2. Given the population of the earth, and

the big 98 people who have died, isn't the hysteria a bit over the top? :shrug:

[Media_Lies_Daily]

4. You're obviously not paying attention, are you? Let me get....

...straight to the point.

This disease has not yet produced an infectious variant that will pass easily among humans. Not yet. At this point in time, the mortality rate is roughly 50%....one half of all of the people that have become ill have died.

The 1918 Influenza Pandemic infected about 800 million people, 44%, out of a total global population of about 1.8 billion. In 1918, most of the world's population was rural, but the Pandemic was able to reach even the most remote of geographic locations. The mortality rate was about 5%...and somewhere in the range of 40 million people died worldwide. In New York City, they stopped counting the dead at 33,000, and the Pandemic was not even at the halfway point. In Philadelphia, priests took horse-drawn wagons into the neighborhoods and literally called for the dead to be brought out.

Now, let's take today's global population of 6.5 billion, 90% of whom live in urban population centers. Let's also assume that like the 1918 Pandemic, 44% of the current population becomes infected with Avian Flu. That means roughly 2,860,000,000 would become ill, and 5% of the sick, or 143,000,000, would die worldwide.

In addition to the sickness and death, think of the effects such a Pandemic would have on the global economy. Key employees would get sick, and some would die. Places of business like shopping malls would be closed indefinitely. Air and sea travel would stop completely. Travel between cities and countries by automobile, bus, and train would slow to a crawl.

I believe the numbers I noted above to be VERY conservative in the event of a modern Pandemic. This is due to the fact that the globe has become highly urbanized, and the mortality rate may very well exceed that of the 1918 version. Hospitals would be overwhelmed by the sheer magnitude of the sick, and the number of existing respirators would fall far short of the numbers needed. Hospitals and the surrounding grounds would become gigantic triage centers...with one-third of those patients set aside to live or die on their own.

If, and that is a MAJOR if, a vaccine is created in the early stages of the Pandemic, how soon will that vaccine be available to the world's population? Who will be selected to receive the vaccine, and how will that selection be carried out?

[SaveElmer]

5. Several thing sneed to be pointed out...

"This disease has not yet produced an infectious variant that will pass easily among humans. Not yet.

Nor is there any way of knowing if it will mutate. Historically the vast majority of viruses do not mutate to become easily transmissable. There is no indication that this one is more likely than any other to do so.

"At this point in time, the mortality rate is roughly 50%....one half of all of the people that have become ill have died."

At this time the mortality rate is 50% of all who we know have become infected. There are indications of asymptomatic infection in the 1997 Hong Kong outbreak where 10% ofthe 1500 tested showed H5N1 antibodies but no symptom. No comprehensive serological survey has been done so no overall conclusion can be drawn

"The 1918 Influenza Pandemic infected about 800 million people, 44%, out of a total global population of about 1.8 billion. In 1918, most of the world's population was rural, but the Pandemic was able to reach even the most remote of geographic locations. The mortality rate was about 5%...and somewhere in the range of 40 million people died worldwide. In New York City, they stopped counting the dead at 33,000, and the Pandemic was not even at the halfway point. In Philadelphia, priests took horse-drawn wagons into the neighborhoods and literally called for the dead to be brought out.

Now, let's take today's global population of 6.5 billion, 90% of whom live in urban population centers. Let's also assume that like the 1918 Pandemic, 44% of the current population becomes infected with Avian Flu. That means roughly 2,860,000,000 would become ill, and 5% of the sick, or 143,000,000, would die worldwide"

This is simply a statistical analysis. There is no way of knowing how virulent the virus would if it did mutate. And there are reasons to believe the unique conditions of WWI were responsible for a strain that was both highly virulent and highly transmissable. These conditions do not exist today. It is more likely the virus will significantly weaken if it does mutate.

"I believe the numbers I noted above to be VERY conservative in the event of a modern Pandemic. This is due to the fact that the globe has become highly urbanized, and the mortality rate may very well exceed that of the 1918 version. Hospitals would be overwhelmed by the sheer magnitude of the sick, and the number of existing respirators would fall far short of the numbers needed. Hospitals and the surrounding grounds would become gigantic triage centers...with one-third of those patients set aside to live or die on their own. "

There are also many factors mitigating against this analysis in the unlikely event of a variant as virulent as the virus is now, including improved medical care and rapid communication which will allow isolation in the event of an outbreak, antibiotics to combat secondary infection, and anti-virals.

[ConcernedCanuk]

6. Umm, I hate to be picky, but using your own analysis . .

.
.
.

"At this point in time, the mortality rate is roughly 50%....one half of all of the people that have become ill have died."

But THEN you conclude

"Let's also assume that like the 1918 Pandemic, 44% of the current population becomes infected with Avian Flu. That means roughly 2,860,000,000 would become ill, and 5% of the sick, or 143,000,000, would die worldwide."

Mortality rate is 50%, not 5

so wouldn't that mean 1.43 BILLION would die worldwide??

Correct me if I missed sumthing here . .

[laundry_queen]

13. He's comparing the 1918...

mortality rate with the rate one might imagine H5N1 may have if it makes the change to become more easily transmissable. The chances of the mortality staying at 50% if a change in the virus makes it easily transmissable is slim. The 1918 death rate was 5% so he was using that as an example. :)

[NIGHT TRIPPER]

9. just a conspiracy theory right?-move along-just a GOP scare tactic-

If Avian flu becoming a pandemic is even a REMOTE possibility,
doesn't that merit:
----1) concern?
-->2)full on researching the virus itself
-->3) full on information gathering?

so many posters are just ready to dismiss it cold...
?
funny

[SaveElmer]

12. Not surprising...

After all the other false alarms we have been treated to, SARS, West Nile, Ebola, Legionnaires, Killer Bees etc etc If the media would provide balanced coverage instead of fear mongering, the reaction would be more reasoned.