Here in the US I’ve noticed that there is almost a panic about an impending flu epidemic (bird or otherwise). Companies are creating contingency plans in case half of their workforce is out sick, and hospitals are bracing for the worse.
We’ve lived with flu viruses for countless thousands (millions?) of years and humans have survived some nasty pandemics in the past… even without the aid of antiviral drugs. With all of our understanding of how this specific virus works surely we can come up with a strategy to deal with it when and if it strikes.
I realize there is no vaccine for this particular strain yet, but what makes this version of the virus so worrisome? Is it immune to our best antiviral drugs? Does it attack our systems in new and more devastating ways?
In short, what makes this particular flu virus so different from all other flu viruses?
I won’t comment on this particular strain because I haven’t quite figured out why it is so bad either. I know the risk spans beyond humans however. If there was an outbreak in the US poultry industry, we could have to potentially slaughter millions to billions of chickens in a fairly short-time. That is a big problem on its own.
Flu viruses in general can be worse than a genocide, war, or terror attack. The influenza virus of 1918 killed up to 40 million people. We don’t have a cure for the flu although we can treat the symptoms but that many cases would swamp the resources of all countries that experienced an outbreak and we may not be that much better off especially with limited vaccine supply and a much higher population.
The problem is that there’s 6 billion humans in the world all living in very tight social clusters. Never before in history have that many people lived that close to each other. What would’ve done major damage in the past could easily wipe most of us out now.
This particular panic is mainly being fueled by the media, who loves a good strategy. After all, the disease we’re all supposed to be terrified of does not actually exist yet. The scientific basis is that this particular strain is unusually deadly. Those that have been infected (from birds and other farm animals) die at a higher rate than most flu strains. The fear is that the virus will recombine with a normal human-to-human strain and gain the ability to spread rapidly while still killing at a high rate. Occasional news reports of human to human transmission aside, this hasn’t happened yet.
People would do well, IMHO, to review the history of the swine flu panic of the 1970s.
Compare to the “minor” outbreak of SARS a few years back. The hospital systems in some major westernized cities (Toronto and Hong Kong) were deepp trouble. Staff were getting sick and some healthy ones were afraid to go to work. Doctors had too few ventilators for the number of sick people and hard choices had to be made. E.g., young vs. old, health pro (who could help if they recover) vs. regular person.
Multiply the density of SARS-level cases by 10 and distribute widely. Then the health care system of the world breaks down. Forget distributing vaccines, medication, getting treatment, seeing a doctor.
And you are still orders of magnitude away from the 1918 pandemic.
Sometime quite soon, Something Bad is going to spread worldwide and millions will die. Because of the change in society since then, the effects on civilization will be far worse. Smart People are trying predict ahead of time which thing is going to be the Something Bad and try to prepare for it. Bird Flu is high on the list.
“Tut-tutting” these efforts is burying-your-head-in-the-sand thinking. The Swine Flu thing is in fact an excellent example of suitable response.
The media does try to scare everyone all the time about everything. But that doesn’t mean that some of the scare stories aren’t true.
While I think the media IS whipping up a frenzy in advance of anything bad actually happening, I wasn’t trying to downplay a potential epidemic. My question, which remains unanswered, is why this particular strain is so deadly. When people start to compare it to other pandemics, and talk about wiping out millions of people, I assume the virus in question must be particularly bad.
Normally, flu cases are caused by variants of virii that humans have played host to for many years. While they change a bit from year-to-year, our bodies have “learned” how to combat them. Bird flu is scary because its a type of flu that has not often previously affected humans, and consequently, we have little or no acquired immunity to it.
More specifically, the hemagglutinin RNA strand in the H5N1 flu, which is a part of the virus commonly targetted by antibodies, has not been previously seen on a strain of flu common in humans. There is evidence that when our bodies are exposed to this strain, our immune systems run amok in a sort of postiive feedback loop, which may be the most literal answer to your question regarding why it’s deadly. The mortality rate for H5N1 is estimated to be 50%.
Of course, any mutation that makes the virus more easily transmissible in humans might also change its effects, and alter that rate. I think I’ll still be washing up after shaking hands with any chicken farmers, though.
the flu is called H5N1. The H and N stand for proteins on the surface of the flu virus (hemagluttin and neuraminidase). The H protein can attach to receptors in the lungs, which is why you can get the flu by breathing (you inhale it, then it attaches to receptors in your lung and invades your cells).
There are 2 kinds of receptors this flu can attach to. One is located in the bottom of the lungs and one near the top and in the throat. Right now H5N1 can only attach to hte receptors in the bottom of the lung. This is good because you can’t cough out or exhale the flu virus. But once the virus mutates to be able to attach to receptors in the throat and upper lungs you will be able to spread it by coughing. When that happens the flu will spread quickly. The flu can mutate by combining with a human flu virus. Either a human or a pig, which have both receptors, can catch both bird & human flu at the same time and potentially have a cell infected by both. If that happens you might get a flu as deadly as H5N1 but as contagious as human flu. Or it can mutate on its own. I remember reading a while back that the H protein is about 11 amino acids away (I think there are about 550 amino acids in an H protein) from binding to the receptors in the upper respiratory system. THis article on the 1918 flu implies only one amino acid changing properly can cause a pandemic in that virus.
The researchers found that avian viruses like the H5N1 avian flu strain prefer to bind to SAalpha 2,3Gal receptors located in the alveoli, the small air sacs at the end of the bronchi.
Humans have these same receptors, which is why the virus can be passed from animal to human. It turns out though that while human viruses can bind to these same receptors, they prefer the SAalpha 2,6Gal cell receptors in the bronchia, those long tubes that carry air into the lungs and end in alveoli.
Because the H5N1 virus can only replicate “efficiently” in the lower regions of the respiratory system, deep inside the lungs, it can’t be passed on as quickly from person to person via coughing or sneezing as a virus that replicates in the upper respiratory system.
I swear I’ve read at least two occurrences of epidemiological testing that went like this (one was in Turkey):
Some people who worked basically immersed in sick chickens got the bird flu, and of the say, 4, who were obviously sick and got diagnosed with it, 2 died, for a 50% death rate. However, the authorities tested other people working with chickens and found 100 or so with the antibodies who weren’t sick enough to get diagnosed, and who didn’t die. The antibodies showed they had been exposed and their immune systems worked. This involves the current, un-mutated bird flu.
So if my recollection and those reports are reliable, it’s not that bad. But public health people are taking it plenty seriously, so maybe I’m a mushbrained optimist. Can someone verify, or shoot down, this lots-more-people-with-antibodies-than-very-sick scenario?
The problem is that it may mutate and if it does it may be more deadly than most flus. If the likelyhood is reasonably high, the problem needs publicity in advance, in order for resources to be allocated to prevent a serious disaster.
Prior posts have pointed out the problems when the medical system gets overwhelmed, and also when society gets disrupted. If too many truckdrivers stay home with their families, food stops getting to everyone who wants to eat, and there are a whole lot of other occupations that we wouldn’t want vacated, either.
There’s been talk of quarantine, but how realistic is that? Say it goes airborne so it spreads as people talk to each other; and people are contagious for several days before they get clear symptoms. Would quarantine work?
Masks. I understand that the virus is spread via droplets breathed, sneezed, coughed, etc, from a prior victim. The droplets evaporate, leaving the viruses which are small enough to penetrate a mask, so if I wear a mask I’m not protecting myself. However, if I wear a mask it catches most or all my droplets so I am protecting you. Verification?
Really good posts to which I have nothing to add… but an anecdote.
I had two great-aunts I never met because they had the discourtesy to die forty years before I was born. They died in the 1918 flu. My nana was one of eleven children of whom nine survived.
They were poor people living in Pennsylvania. My nana’s mother had a small general store in a room in the first floor of the house where they rented a room upstairs to live. When the mother and father contracted flu along with most of the brothers and sisters and were too sick to care for themselves, they were taken away to hospital. My nana and several kids we would now call too young to be left alone lived off the staples in the general store for the several days until the first older sibling came back. I imagine her eating straight white sugar from the barrel with several other kids from three to niine.
When the two oldest sisters came back, the family was shocked to see that their beautiful long hair had been shaven to the scalp. Back then this carried implications of “fallen women” and was a deep shame to them. They had been growing their hair long all their lives, and keeping it put back and up in public, the idea being that when you married your husband (virgin, naturally) you took your hair down on your wedding night, and the cascade of hair signified sexual freedom within marriage. To be shaven publically before you were eighteen… horrible. My nana remembered it in my childhood with as much emphasis as the deaths of the two that didn’t come home.
By the way, as she hastened to explain to me, tbe orderlies had shaved everyone’s hair, because the nurses were run off their feet and had no time to wash and clean thousands of sick women’s hair… and lice were a problem.