MALTA—Contagion, a film released earlier this month, depicts a gruesome outbreak of an exotic and deadly new virus. In the real world, a not-so foreign infection is circulating among animals every day of every year. If it picks up just a handful of certain mutations, it could start spreading among people, with a mortality rate as high as 60 percent. What is this potent virus? The flu.

Although the 2009 pandemic of influenza A H1N1 ended up being relatively mild—killing about one in 10,000 people who came down with it—it still claimed more than 14,000 lives across the globe. The relatively low mortality rate was a relief to forecasters because the outbreak's origin in Mexico and type had taken many by surprise.

Such surprises have turned out to be one of the few constants in the virus world: "Expect the unexpected," Ab Osterhaus, a professor of virology at the Erasmus Medical Center in Rotterdam, said here Tuesday at the fourth European Scientific Working Group on Influenza (ESWI) conference.

The uncertainty factor makes global preparedness particularly challenging. And given the basic questions that remain to be answered—such as why some healthy people die of the flu and others do not—researchers are using new technologies to look for leads in victims as well as in the virus itself.

Because, as scientists and public health experts seemed to agree: "What is clear is that it is when, not if," Frederick Hayden, of the University of Virginia School of Medicine, said here on Tuesday, referring to the next influenza pandemic—one of many proclamations of coming plague during the meeting that was tinged with just enough urgency to generate attention (and research funding) but not ignite an all-out panic.

Ongoing research is providing some new clues about what type of virus might become pandemic, where it might emerge and who it is most likely to kill.

Mysterious mutations
Topping the worst-case scenario list for most flu experts is a pandemic of H5N1, the "bird flu" which has killed about six in 10 people who have gotten it—a total of at least 550 people since 2003—and has laid to waste hundreds of millions of domestic fowl and wild birds.

Fortunately, so far, it has not been transferred from human to human and has passed to us only via direct contact with animals. But any flu can change rapidly, mutating in each new host. So researchers wonder: Could the dreaded H5N1 ever morph into a disease that could spread among people, via a cough or sneeze, to attach to nasal or tracheal membranes, as the seasonal flu does every year?

To help answer this question, Ron Fouchier, also of Erasmus Medical Center, and his team "mutated the hell out of H5N1" and looked at how readily it would bind with cells in the respiratory tract. What they found is that with as few as five single mutations it gained the ability to latch onto cells in the nasal and tracheal passageways, which, Fouchier added as understated emphasis, "seemed to be very bad news."

The variety that they had created, however, when tested in ferrets (the best animal model for influenza research) still did not transmit very easily just through close contact. It wasn't until "someone finally convinced me to do something really, really stupid," Fouchier said, that they observed the deadly H5N1 become a viable aerosol virus. In the derided experiment, they let the virus itself evolve to gain that killer capacity. To do that, they put the mutated virus in the nose of one ferret; after that ferret got sick, they put infected material from the first ferret into the nose of a second. After repeating this 10 times, H5N1 became as easily transmissible as the seasonal flu.

The lesson from these admittedly high-risk experiments is that "the H5N1 virus can become airborne," Fouchier concluded—and that "re-assortment with mammalian viruses is not needed" for it to evolve to spread through the air. And each of these mutations has already been observed in animals. "The mutations are out there, but they have not gotten together yet," Osterhaus said.

9 Comments

1. 1. Torchlake 12:58 PM 9/19/11

   Wouldn't it be prudent to keep the pressure on the public to be repaired as best we can. Example..Does a hepa-filter in a confined area be effective in creating a somewhat safe area? Should the public have face masks? The CDC has a nice web-page on these matters? Try reading "The Great Influenza" This is a real eye opener as to what will occur....! not IF...WHEN!
   
   
   
   
   
   
   

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2. 2. ASHIK 01:14 PM 9/19/11

   It is a never ending fight with mutating viruses for sure.Preparation to fight against next flu attack could only be possible if scientists can predict it accurately and in advance.Lets hope we win every single time virus attacks in the future.
   

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3. 3. mr2sheds 01:46 PM 9/19/11

   I think you are missing the real story here...FERRETS?
   
   

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4. 4. biomedical 06:04 PM 9/19/11

   Health experts and CDC scientists seem to all agree that "it is not if, but when a real, large scale pandemic will occur," and Public Health officials are realizing that front-line respiratory protection is critical. I keep hearing people as … "will we be prepared?" Bio-Medical, http://www.maxair-systems.com

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5. 5. rumyan 10:17 AM 9/20/11

   
   The 2009 pandemic of influenza A H1N1 has been relatively mild. It killed about one in 10,000 people who came down with it. The pandemic claimed near14,000 lives across the globe i.e. less than 0.0002% of world population. The most basic question that arises immediately - why 0.0002% of healthy people died of the flu and others 99, 999% did not. This question is most basic and it must be answered first of al. Unfortunately, the experts cited in the discussed letter don’t focus their attention on relevant traits of most susceptible human individuals. They continue to exploit infertile idea of prevalent value of virus mutations. What is more, they ignore the observations and technologies evidenced genetic nature of individual differences in human susceptibility to influenza has been published in the article “Genetic immunity and influenza pandemics” (FEMS immunology and medical microbiology 2006;48:1-10) and in the book “Hereditary Immunity: Fundamental Principles and Exploitation in Life Study and Health Care” (New York: Nova Biomedical Books, 2008).
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6. 6. bucketofsquid 04:17 PM 9/23/11

   So out of curiosity this guy weaponized H5N1 virus and he only had to do a handful of variety combinations and then spread it through 10 hosts before it became airborn and thus weapon suitable. An airborn virus with a 60% fatality rate of infected persons is pretty impressive. I wonder how much he is selling it for.

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7. 7. rumyan 05:07 PM 9/23/11

   Dear "bucketofsquid”, the answer to your questions you can find inside of the book entitled "Is Bioterrorism Idea a Delusion or Skillful Swindling?" Puurs, Belgium: UniBook, 2010.
   
   
   

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8. 8. Wayne Williamson in reply to bucketofsquid 08:25 PM 9/29/11

   reminds me of the movie 12 monkeys....

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9. 9. JamesRoday in reply to mr2sheds 11:14 PM 1/23/12

   Would you rather... HUMANS?

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