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In 6 months, 1 billion dead in avian flu?

  1. Nov 23, 2004 #1
    :bugeye:
    http://www.mosnews.com/news/2004/10/28/pandemic.shtml

    Others are more optimistic:
    http://www.theglobeandmail.com/serv...117.wpan1117/BNStory/specialScienceandHealth/

    Not that I understand how they get these optimistic number since avian flu has had a fatality of about 70% of those infected.
     
  2. jcsd
  3. Nov 23, 2004 #2

    russ_watters

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    Well, where does the Russian agency get 70%? I'd be more inclined to believe 1% - its "only" the flu.

    [google...]HERE appears to be the source:
    One danger here is sample size - the 30% was 6 out of 18 (from another site). With that small of a sample, you can get a sample bias.SOME THINGS to remember about the flu - it kills roughly 36,000 people a year in the US and 90% are over age 65. I'm having trouble finding a death rate - probably because a significant fraction of cases go unreported.
     
  4. Nov 23, 2004 #3
  5. Nov 23, 2004 #4
    But the WHO and CDC quotes much lower number and hopefully are more correct. Unless they are conservative and wants to avoid a panic.

    The worst flu until now was probably the flu of 1918, which killed 20-50 million. A flu of similar severity could kill many more since world population has increased 3-4 times since that. But maybe better knowledge can give more effective countermeasures today. Hopefully vaccination could protect those in rich countries several months after an outbreak. There are some expensive anti-virals that also may help, especially as profylax, but also only a very small number of people initially. Probably restricted to health care professionals.

    Large number of cases could overwhelm at least the health care system and maybe also other parts of society, for example food distribution. Especially from panic.
     
  6. Nov 23, 2004 #5
    Case Mortality Rate

    The case mortality rate in the 70-80% is pretty solid. There were human cases in Vietnam and Thailand at the beginning of this year, and then another wave over the summer. All data sets have case mortaility rates in the 70-80% range.

    The key question concerns human to human transmission. If the H5N1 virus just picks up the abilty to recognize human receptors via recombination

    http://www.recombinomics.com/viral_evolution.html

    the virus can acheive a high transmission rate and maintain the high case fatality rate (which is much higher than seen in the 1918 flu pandemic).

    CDC and WHO are being VERY conservative (and optimistic) by assuming that the case fatality rate would fall from 70% to 1%.
     
  7. Nov 23, 2004 #6
    Last edited: Nov 23, 2004
  8. Nov 23, 2004 #7

    arildno

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    Dearly Missed

    We shouldn't hold on to a too bleak perspective on this, as long as we steel ourselves to endure some harsh measures in the event of a pandemic without functional vaccines:

    One tends to forget that tuberculosis in the Western world was successfully combated without really efficient vaccines:

    What the health authorities did, was wide-spread use of quarantining infected individuals, and, by being efficient in this, were largely successful of containing outbreaks at manageable levels.

    (Tuberculosis remains, however, one of the most widespread diseases today, particularly in 3rd world countries with inefficient local health authorities&restricted access to vaccines/antibiotics.)

    If our health authorities (surgeon generals and the like) dare to implement the sufficient restrictions on peoples' movement (i.e, freedom), such a pandemic can be kept in check, even if we at present lack efficient medicines to combat the plague directly.
     
  9. Nov 23, 2004 #8
    New Vaccines

    The technologies exist not only for stockpiling vaccines, but also for predicting new isolates before they emerge

    http://www.recombinomics.com/vaccine_development.html

    but its easier to do on paper than scale up to make billions of vaccines.
     
  10. Nov 23, 2004 #9
    Influenza is a nightmare to try to quarantine. If I remember correctly an comparison between SARS and influenza, someone holding a lecture might infect a person right next to him with SARS. He might infect everybody listening in a large room with influenza.

    Here is a map of the spread of the 1918 epidemic. Click on maps:
    http://history1900s.about.com/gi/dy...s.org/wgbh/amex/influenza/timeline/index.html

    Today everything will go much quicker because of airplanes and cars. But I expect that closing of schools, public meetings, entertainment centers and so on will be tried. But that were also tried in 1918 but then there were also many mass gatherings after the war and when the soldiers returned. It will not be possible to stop people from meeting at work and in shops.

    Here is an interesting paper that seem to indicate that very strong quarantine might be effective. (I have only read the free abstract):
    http://www.pnas.org/cgi/content/abstract/0407293101v1?view=abstract
     
    Last edited: Nov 23, 2004
  11. Nov 23, 2004 #10
    Quarantine


    The effectiveness of quarantine really depends of the organism. For SARS quarantine may have helped because peak levels of virus shedding was several days after symptoms (and seasonal factors may have played a fairly major role).

    Flu can move around pretty quickly and there are some major issues regarding under devloped contires and rural areas

    http://www.recombinomics.com/flu_laos_cambodia.html

    I think flu, if human to human transmission is efficient, will be very tough to control by quarantine.
     
  12. Nov 23, 2004 #11
  13. Nov 23, 2004 #12

    iansmith

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    I just want to add that one simple sanitary measure was responsible for the decrease of the level of transmission of TB and other infectious microorganism. This measure is called pasteurization. Prior to pasteurization, milk was one of the major infection vector. The Cow TB could be pass to human by milk. This is a major problem in the underdeveloped countries.

    The same thing can be applied to influenzae. The major cause of outbreak is bad sanitition at the farm level. Duck pass influenzae to pig or human, human or pig exchange the virus. Sanitation would the best way to go for now because most of the transmission is done via the duck-human path.
     
  14. Nov 23, 2004 #13
    How about killing all ducks? Setting a reward for each killed duck would be quite effective. We can keep some tucked away in zoos. Sure, they are probably important in the ecosystems for eating insects or something similar but that would seem to be a small price for stopping this catastrophe. Not to mention that they are also the silent carriers of the ordinary yearly flu which kills tens of thousands each year in the US alone.
     
  15. Nov 23, 2004 #14

    iansmith

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    Killing all the duck might be an over-reaction. Duck are asymptomic carriers, except with some recent cases.

    The problem with chinese farming is that the duck and the pigs are in close contact and the hygene level is below any statisfactory standard. The problem does not really exist in the americas and europe. The solution would be for the chinese government to educated their farmer and change their pratice. The pandemic will not occur if those simple rules are followed.
     
  16. Nov 23, 2004 #15
    The farmers in southeast Asia are still very poor and it may not be possible for them to separate their free-ranging tame birds from wild ducks. That and education would take a long time. Killing the ducks could be done quickly.
     
  17. Nov 24, 2004 #16
    Much has been made of pigs as a "mixing vessel". However, H5N1 has evolved considerably and it is not clear that a mammalian mixing vessel is required for H5N1 to acheive human to human transmission.

    The most prevelent serotype in Asia is H9N2 and some H9s already have human receptor binding sequences. Moreover, some H5N1 isolates from dead patients grow assymptomatically in ducks, and the ducks excrete high levels of virus.

    Thus, a dual infection involving H9N2 and H5N1 in birds could generate a recombinant with the high case mortality associated with H5N1 and human recptor binding properties seen in H9N2

    http://www.recombinomics.com/H5N1_H9N2.html

    Thus, a pandemic strain can evolve without pigs, humans, or high density farms and a little recombination can go a long way

    http://www.recombinomics.com/pandemic_potential.html
     
  18. Nov 24, 2004 #17
    Global pandemic will finish us all, not nukes.
     
  19. Nov 25, 2004 #18
    H5N1 Mating and Mutating

    Today Reuters has a story on the looming flu pandemic. The use a 1% case fatality rate, which is VERY optimistic. They also state that there has been no evidence of H5N1 mating and mutating, which is clearly wrong

    http://www.recombinomics.com/H5N1_mating_mutating.html
     
  20. Nov 25, 2004 #19
    Last edited: Nov 25, 2004
  21. Nov 25, 2004 #20
    It Is 2004

    Check out the calendar. It is 2004. 1997 saw the first documented human H5N1 cases. 6 of the 18 confirmed cases died. That's a case fatality rate of 33%.

    The H5N1 circulating in Asia has evolved quite a bit since 1997, which is why the 1997 pandemic vaccine is not very useful and a new vaccine is being prepared. Although there have not been in documented H5N1 human fatalities in China or Hong Kong, the H5N1 in Vietnam and Thailand has some unique polymorphisms

    http://www.recombinomics.com/swine_human_signatures.html

    and WHO has already acknowledge "probable" human to human transmission in Thailand

    http://www.recombinomics.com/human_human_probable.html

    The H5N1 in Thailand and Vietnam is Amantadine and Ramantadine resistant due to TWO mutations in M2. The case fatality rate in Vietnam and Thailand at the beginning of 2004 and more recently is in the 70-80% range, and acquisition of the human receptor binding domain could create more efficient human to human transmission, while maintaing the 70-80% case fatality rate.

    http://www.recombinomics.com/H5N1_reassort_recombine.html
     
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