Why bird flu is so hard to catch

Times Online ^ | March 23, 2006 | Mark Henderson

[tucker93]

Fears that human beings could fall prey to a pandemic have been eased by new research

SCIENTISTS have explained why the bird flu virus does not readily spread from person to person, shedding light on how it would need to mutate in order to cause a human pandemic.

The H5N1 influenza strain struggles to infect cells high up in the human airway, significantly limiting the extent to which victims can pick up the virus and pass it on by coughing and sneezing, according to research. The findings, from separate teams in the United States and the Netherlands, suggest that H5N1 will probably have to evolve substantially if it is to become easily transmissible between people; the key step that would make a pandemic possible.

[luvbach1]

So the lesson is: don't kiss your budgie!

[ElkGroveDan]

Birds don't send their kids to pre-school. If they did, we'd all get it.

[Redbob]

And whate exactly is preventing this virus from further evolving?

[CharlesWayneCT]

Nothing, but that is no more likely than any of a number of other viruses evolving into something pandemic.

You don't want to blow the budget preparing for THIS, and then get hit by an evolution of some cow infection.

[MJemison]

Does this mean I have to get rid of my layin' hens?

[Battle Axe]

Ping

[La Enchiladita]

At least ... don't French kiss your budgie.

[Altair333]

"Nothing, but that is no more likely than any of a number of other viruses evolving into something pandemic. You don't want to blow the budget preparing for THIS, and then get hit by an evolution of some cow infection."

I wish you had informed the world's most renowned infectious disease scientists of this amazing fact. For some reason, they are far more concerned about H5N1 becoming a pandemic virus than some random "cow infection." Perhaps because H5N1 is extremely similar genetically to the 1919 H1N1 virus which killed tens of millions of people. But I trust your anaylsis over theirs- by all means issue a press release.

[Billthedrill]

And what exactly is preventing this virus from further evolving?

Nothing at all - in fact, virii are constantly mutating. How difficult the right mutation is remains the question - if it were very easy it would be widespread by now but it obviously isn't impossible because it's happened before with other virii.

This isn't one to panic over but we'd be fools not to be careful with it. IMHO.

[cgk]

LOL.

[kinghorse]

Because he wanted to watch time fly? Oh wait. wrong riddle.

[kinghorse]

Great. I blew the punchline. See time fly. Oh wait. Still wrong riddle. It's hard to catch because you are too busy trying to catch the watch your threw out the window to see if time could fly. There I got it right. What a little moron I can be.

[HHFi]

Sorry, I have 13 pet parrots, from a budgie up to an African gray, and I'm not going to stop kissing them. If I ever did, they'd say, "What, is it my breath?"

[FBD]

Another point of view, by a conservative doctor:

ELIMINATING BIRD FLU FEARS

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1. The death rate from H5N1 infection is highly overstated.

Between Dec. 26, 2003 and Oct. 24, 2005, there were 121 confirmed H5N1 infections and, of those, 62 have reportedly died. That makes the “apparent” death rate just over 51 percent, ranking this infection among the most deadly on record.

However, thousands of mild and asymptomatic cases are going undetected as detailed by Dick Thompson, a spokesperson for the World Health Organization (WHO). In an interview granted to CIDRAP (Center for Infectious Disease Research and Policy) News on March 9, 2005, Thompson said that the case-fatality rate had been overstated. Documented cases were those where the patients were sick enough to seek medical care in a hospital and, predictably, they had very poor outcomes. He concluded, “Surely others were infected and either not getting sick or not getting sick enough to seek treatment at a hospital. Factoring those into the CFR [case-fatality rate] has been impossible. We simply don't know the denominator.”[2]

To illustrate, if 62 people died, but 10,000 had actually been infected, the death rate would be 0.62 percent, essentially insignificant. Therefore, without knowing how many are infected, the death rate is being highly inflated

2. The virus has barely infected humans; significantly, there has been no sustained person-to-person transmission of the infection.

Very few cases of severe human infection by H5N1 have occurred. An intensified surveillance of patients in Southeast Asia has led to the discovery of mild cases, more infections in older adults, and an increased number of “clusters cases” among family members, suggesting that “the local virus strains may be adapting to humans.” In other words, humans are developing their own innate resistance to the virus.[3]

In addition, all cases have occurred via animal-to-human transmission, and there is documentation of only one confirmed case of human-to-human transmission. Without sustained transmission between humans — meaning one person spreads it to another and another, and so on — there can be no pandemic. The “hype” that, sooner or later, the H5N1 strain will mutate into a strain that can be easily passed between humans is completely unsubstantiated. Whether this will happen is nothing more than a guess because:

3. We have had “potential pandemics” before.

In February 2003, Thompson of the WHO revealed that “there have been a half dozen pandemic ‘false alarms’ in the last 30 years.” A false alarm is an outbreak where a virus has jumped the species barrier, but has been confined to one or two people and has not been lethal...."[4]

{snip}

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