Avian flu threat?

[Helix]

So Avian flu, H5N1, had been in the news lately and is widely heralded as a large threat to humanity, similar in genetics and potential impact to the 1918 pandemic.

 

Is Avian flu this much of a threat? Is this media hype gone overboard OR are our government leaders shunning a serious health risk?

 

Also, what type of impact would avian flu have on humanity, how much damage would really be wrought (realistically)? Do we have enough vaccines?

 

Personally, I think this is a risk but because of all the hype people are freaking out and therefore the governments are collectively saying "We should handle this before riots break out." So, in my view, avian flu isn't as much of a threat as it could be because of the panic.

 

Genetically, I think avian flu is a monster. Part benign airborne, part deadly groundborne total killer (sorry for the movie-previewesque comparison). This virus is a very real threat and would kill many people, but as I said, probably won't.

 

 

So enough rambling, what do you think? Hype? Apocolypse? Just-another-virus-because-we're-raping-the-planet-and-we-deserve-this?

[Douglas]

Also' date=' what type of impact would avian flu have on humanity, how much damage would really be wrought (realistically)? Do we have enough vaccines?

[/quote']

Apparently there *is* a vaccine for this flu. I heard or read that the American pharmaceuticals are reluctant to produce the vaccine for fear of the liability (a good reason for tort reform).

 

I heard from another source that the 1918 pandemic was a form of the avian flu and that it was expected that the world would experience 3 pandemics per century.

[Celeste22]

Originally Posted by Douglas

I heard from another source that the 1918 pandemic was a form of the avian flu and that it was expected that the world would experience 3 pandemics per century.

 

Avian influenza is an infectious disease of birds caused by type A strains of the influenza virus. The disease, which was first identified in Italy more than 100 years ago, occurs worldwide.

 

All birds are thought to be susceptible to infection with avian influenza, though some species are more resistant to infection than others. Infection causes a wide spectrum of symptoms in birds, ranging from mild illness to a highly contagious and rapidly fatal disease resulting in severe epidemics. The latter is known as “highly pathogenic avian influenza”. This form is characterized by sudden onset, severe illness, and rapid death, with a mortality that can approach 100%.

 

http://www.who.int/mediacentre/factsheets/avian_influenza/en/

 

This article from the WHO sums it up pretty well. Personally, this Avian H5N1 scares the shiznit out of me.

[Douglas]

http://www.who.int/mediacentre/factsheets/avian_influenza/en/

 

This article from the WHO sums it up pretty well. Personally' date=' this Avian H5N1 scares the shiznit out of me.[/quote']Good link Celeste.

Yeah, I'm concerned too, I'd like to see immediate action on developing a vaccine.

 

I heard that Bush was looking into the feasability of a quarantine of affected areas.

[Helix]

 

I heard that Bush was looking into the feasability of a quarantine of affected areas.

 

Yes, that would be a Bush response. Don't fix the problem, isolate it and let it die. It worked in Iraq right...right?

 

But the three pandemics a century sounds frightening but when you consider how fast modern transportation is, getting a virus around the world could feasibly take a few days. Scary thought. I wonder what the governments would collectively do if this turns out to be Number 1?

[rakuenso]

Another Bush answer would be to nuke india,

 

however, there has to be delicate balance between vaccine production.

 

We can't both stock up vaccine for the H5N1 strain without straining the production capabilities of the "normal" strain. You can see how this would pose a problem, as if we augment falsely the production of vaccines for the H5N1 strain, we won't be able to stock up on the normal strain. Where millions more might die as a result of lacking the normal vaccine. Secondly, we can't just make a new vaccine for instance the day we find that there's a pandemic, these vaccines take months to prepare.

[Helix]

That's a good point; where do we strike the balance between preparing for a potential - not certain - disaster and protecting from the yearly assult?

 

I personally feel that even if a balance is struck, there is a fundemental problem with the vaccine and its development/distribution. First, how do we know it will hold up to a pandemic? How much clinical research has been done? Secondly who will pay for it, the government and add to the enormous national and international debt? What if they don't want to spend the money, do we all just die?

 

Many questions, few answers. If we get hit, it will be sort of comical. All this "preperation" when really not a lot is being done.

[H W Copeland]

I understand that it is not contagous person to person, so how would it break out in such numbers as to be a pandemic?

[rakuenso]

then you understood wrongly, very wrongly

[Mokele]

Actually, from what I've heard, he's *currently* right, and the current form has difficulty passing to humans and between humans. The problem is that a few simple mutations could overcome that difficulty, and result in improved transmission and very, very big problems.

 

Mokele

[rakuenso]

The H5N1 strain obviously is not very effective at human-human transmissions, else it would've spread all over the world by now. I thought he meant the current not so deadly H9 strains, which can easily be transferred from person to person.

[Helix]

Right H5N1 is currently not easily transmisible person-to-person. The fear is, however, that that won't last and it will evolve into something more pathogenic.

 

What if H9 and H5N1 would cross infect in the same species (i.e. both strains infect the same pig)? That would mix the viral genes and create this problem far more quickly than anticipated.

[Celeste22]

The H5N1 strain has killed more than 60 people in South East Asia since 2003.

However, of those only one is suspected to have died after catching the virus from another human.

 

It appears that H5N1 has made it's way to Europe now.

European countries are stepping up measures to prevent the spread of bird flu, following the discovery in Turkey of the H5N1 strain dangerous to humans.

 

13 October 2005

 

Tests conducted by the World Organisation(UK) for Animal Health (OIE) have today confirmed the presence of highly pathogenic H5N1 avian influenza in samples taken from domestic birds in Turkey.

http://www.who.int/csr/don/2005_10_13/en/index.html

 

Are there drugs available for prevention and treatment?

 

Yes. Two classes of drugs are available. These are the M2 inhibitors (amantadine and rimantadine) and the neuraminidase inhibitors (oseltamivir and zanimivir). These drugs have been licensed for the prevention and treatment of human influenza in some countries, and are thought to be effective regardless of the causative strain.

 

However, initial analysis of viruses isolated from the recently fatal cases in Viet Nam indicates that the viruses are invariably resistant to the M2 inhibitors. Further testing is under way to confirm the resistance of amantadine. Network laboratories are also conducting studies to confirm the effectiveness of neuraminidase inhibitors against the current H5N1 strains.

 

Are presently available vaccines useful in averting an influenza pandemic?

 

Yes, but in a precisely targeted way. Current vaccines, when administered to high-risk groups, such as poultry cullers, protect against circulating human strains and thus reduce the risk that humans at high risk of exposure to the bird virus might become infected with human and avian viruses at the same time. Such dual infections give the avian and human viruses an opportunity to exchange genes, possibly resulting in a new influenza virus subtype with pandemic potential.

 

Annual vaccines are produced for routine use in protecting humans during seasonal epidemics of influenza. They offer no protection against infection with the H5N1 avian virus.

 

For these reasons, WHO has issued guidelines for the vaccination, using the current trivalent influenza vaccine, of groups considered at high risk of exposure in countries experiencing outbreaks of highly pathogenic H5N1 avian influenza in poultry.

[H W Copeland]

The H5N1 strain obviously is not very effective at human-human transmissions, else it would've spread all over the world by now. I thought he meant the current not so deadly H9 strains, which can easily be transferred from person to person.

 

Didja now....

 

Why would you think that? The thread is about H5N1.

[rakuenso]

because you asked such a question with a rather obvious answer, so therefore i inferred you were talking about H9 strains

[H W Copeland]

because you asked such a question with a rather obvious answer, so therefore i inferred you were talking about H9 strains

Why would I do that? As I said, the thread was about H5N1.

 

We have all been following the news about this strain and one of the little tidbits of good news was that it is rarely contagous between humans.

 

So, the question remains, how is it likely to cause a pandemic when all one has to do is stay away from birds?

[Celeste22]

Originally Posted by H W Copeland

So, the question remains, how is it likely to cause a pandemic when all one has to do is stay away from birds?

 

I think the word you need to remove is "likely". No one knows yet.

 

Right now, I believe people are worried about the past history of similiar virus's.

When you look at that factor, and the obvious nastiness of H5N1, add world wide bird population & the population of people working around said, times that by probability of evolution or mutation of said virus from bird/bird transmission to bird/human (already happened) to human/human, and what you get is one giant nasty killer that would have a very high probability of becoming pandemic.

 

A BRIEF TIMELINE

 

1890

First recorded recent influenza pandemic

 

1918

The “Spanish Flu” pandemic, caused by the H1N1 influenza virus, kills more than 40 million people. The origin of H1N1 remains a mystery, but may have involved incubation in an intermediate host, such as the pig, or another as yet unidentified animal host.

 

1957

Asian flu pandemic kills 100,000 people, due to the H2N2 influenza virus.

 

1968

Hong Kong flu pandemic kills 700,000 people, due to the H3N2 virus. Both H2N2 (1957 pandemic) and H3N2 are likely to have arisen by exchange of genes between avian and human flu viruses, possibly following dual infection in humans.

 

21 May 1997

Bird flu virus H5N1 is isolated for the first time from a human patient in Hong Kong. The virus infects 18 patients after close contact with poultry, with six deaths. Fortunately the virus does not spread from person to person. Within three days, Hong Kong's entire chicken population is slaughtered to prevent further outbreak.

 

Feb 2005

A report of probable person to person transmission of bird flu (H5N1) in Vietnam is published (New Engl. J. Med, 352 333–340)

[rakuenso]

Also note that a species crossing flu doesn't have to infect humans. As an H9 variant can also mutate and infect a bird with the H5 strain as opposed to the commonly accepted H5 affecting H9 human

[H W Copeland]

Or we can resurrect a variant that has a worse track record:

 

http://www.townhall.com/opinion/columns/charleskrauthammer/2005/10/14/171278.html

[Celeste22]

Originally Posted by H W Copeland

Or we can resurrect a variant that has a worse track record:

 

http://www.townhall.com/opinion/colu...14/171278.html

 

Very scary indeed. But....in light of the Avian H5N1 emergence, and it coming from an intermediate host, possibly part Avian, we had good reason to resurrect it.

By studying genes of the 1918 influenza virus, scientists can further characterize factors that made the virus so virulent, and thusly, find methods of prevention or treatments.

 

Where Did the 1918 Influenza Virus Come From?

Using these old lung tissue samples, the complete sequence of the hemagglutinin gene has now been identified. This sequence indicates that many avian characteristics are present in critical locations, such as receptor sites, antigenic sites, and glycosylation sites, suggesting an avian origin of this virus. However, despite the presence of avian features, this virus is related to human viruses and is also closely related to swine viruses.

Laurent Kaiser, MD

 

 

Dr. Jeffery K. Taubenberger and colleagues at the Armed Forces Institute of Pathology in Rockville, Maryland, report their findings from mapping the polymerase genes of the 1918 influenza virus. They point out that the influenza A polymerase proteins PA, PB1 and PB2 are involved in many aspects of viral replication and that they likely play a role in host specificity.

 

The authors observed that only 10 amino acid positions out of more than 2,000 codons distinguished the 1918 and subsequent human influenza polymerase proteins from avian influenza. Moreover, some of these changes are shared by some highly pathogenic avian H5N1 avian viruses currently circulating in Asia that have infected humans.

This suggests," Dr. Taubenberger said in a statement, "that these H5N1 viruses might be acquiring the ability to adapt to humans, increasing their pandemic risk."

 

Dr. Tumpey's group concludes by pointing out that the antiviral drugs oseltamivir and amantadine are effective against viruses carrying the 1918 neuraminidase and M genes. Also, a recently developed vaccine containing the 1918 hemagglutinin and neuraminidase were protective in mice.

[Nevermore]

What would happen if a human with the generic flu caught this as well?

[T-Nemesis]

^The two will bond to form a supervirus.

[Helix]

Well possbily. That's not a scientific fact that they will but merely that they could given the proper cirumstances. If that would happen, many would die.

[EvoN1020v]

If the H5N1 virus mutate into human form, then the diease would became contagious. But its mainly in the field of poultry where it killed millions of birds. Also an empedic virus would stow for sometime and then magically reappeared anytime in the century. When we prevent that virus with a new vaccine, then the virus would stow for some more times. Then suddenly reappear with stronger protective. i.e. Spanish Flu in 1918 hide then now in 2005 it reappeared in a slight different form. Our planet is a crazy world today with science!! Though, I love the entairnment of science and keep us scientists really busy!

[rakuenso]

just out of curiosity, does our body have a gene encoding for neuraminidase for the hell of it?