Sunday, December 31, 2006

One flu over the cuckoo's nest

Flu fearmongers must be quite depressed these days. Seasonal flu is late. Bird flu - despite all the headlines - hasn't gained much traction among humans. And we haven't had pandemic flu in 36 years. The good news is so good (for the rest of us, that is) that the flu lobby seems to be resorting to manufacturing fantasy flu statistics.

A new study published this week in the medical journal The Lancet (Dec. 23/30) estimates that a global pandemic flu could result in 62 million deaths worldwide, mostly in poor nations. The researchers naturally conclude that "prudence" requires "focusing on practical and affordable strategies for low-income countries where the pandemic will have the biggest effect." But the study is yet another example of how out-of-touch with the real world some public health researchers can be.

First, the researchers' estimate of 62 million deaths has far more shock-value than credibility. It's guesswork derived from other (cherry-picked) guesswork. The 62 million-death sound-bite is the product of statistical modeling that uses worst-case death rate estimates from the 1918-1920 pandemic influenza - an epidemic that medical historians believe killed somewhere between 20 million to 100 million people. In addition to the obvious uncertainty surrounding the actual death toll from the 1918 flu pandemic, the researchers ignored several key (not to mention glaring) differences between 1918 and 2006.

First, while there's no sure-fire cure or preventative measure for the flu, modern medical care and public health practices have dramatically improved since 1918. So any flu epidemic is likely to be far less severe - a point we'll come back to in a moment. Next, a great proportion of the deaths in 1918 was probably due to secondary bacterial infections that followed the initial viral infections. Today, antibiotics would be used to treat bacterial infections. And let's not forget that during 1918-1920, much of the world was still recovering from the strains of World War I. Poverty, hunger, unsanitary living conditions and stress likely made much of the global population ripe for a killer flu pandemic. None of these considerations were factored into the researchers' estimate of 62 million deaths.

But perhaps the researchers' choice that most reveals their apparent desire to come up with a scary - rather than a realistic - death toll from pandemic flu is their decision to use the 1918 pandemic flu data in the first place. There were, after all, two other more recent and, in all likelihood, more relevant pandemic flu outbreaks in the 20th century. There was the 1957-58 Asian flu pandemic that killed somewhere between 1 million to 4 million people. The 1968-1969 Hong Kong flu killed an estimated 750,000 people.

Now if one wanted to estimate a death toll from a hypothetical pandemic flu in today's world, it seems as though data from the Asian and Hong Kong flu pandemics would be much better starting points than the far more uncertain data from a chaotic period almost 90 years ago. That presumes, of course, that one is interested in more realistic (albeit smaller) estimates that better reflect modern conditions as opposed to overblown numbers aimed at producing scary headlines.

What this sort of study reveals is how public health researchers can put more stock in frightening the public than informing it. It's as though they assume that we're too stupid to work with facts and must be terrified into action.

And then, what is the action that the researchers desire? In this case, they want more money allocated to pandemic flu preparedness. While this may sound reasonable at face value, let's consider several key realities. First, pandemic flu is quite rare and we ought to be cautious not to over-allocate scarce public resources to events that seldom happen and that seem to be getting less severe when they do occur. Next, millions of people in the developing world die every year from preventable diseases, such as mosquito-borne malaria and diarrheal diseases caused by unsafe food and water. Why not spend available resources on saving people from those deadly diseases that are taking lives right now rather than on over-preparation for a hypothetical epidemic that is highly uncertain. Moreover, by tackling these other ongoing diseases, populations will be made less vulnerable to pandemic flu should it occur.

Finally, pandemic flu frenzy is also a problem in the U.S. The federal government has already spent $600 million in local and state government preparedness planning for a pandemic flu that may or may not happen any time soon, according to a report this week in the Chicago Tribune. That "preparedness" includes stockpiling vaccines - a stockpile that could very well prove entirely useless since no one can be certain that the vaccines will be effective against a specific strain of flu virus from which pandemic flu might actually develop. Useless preparation may be worse than no preparation because it means that precious public health resources, efforts and time have been wasted.

If we can't expect truthfulness and clear-thinking from public health researchers and officials in a time of relative calm, how much confidence can we have in them should a public health emergency develop?


Super vaccine for flu

SCIENTISTS are on the verge of producing a revolutionary flu vaccine that protects against all major strains of the disease. Described as the "holy grail" of flu protection, it would fight off all 24 types of influenza A, including the deadly bird flu and nasty winter outbreaks. Two injections could give long-lasting immunity, unlike current vaccines that must be administered every year.

After years of research, UK and Belgian researchers say the breakthrough vaccine is now one step closer to public release. Scientists from British biotech firm Acambis and Flanders Interuniversity Institute for Biotechnology in Belgium will test the super vaccine on humans for the first time in the next few months.

Australian influenza experts welcomed news of the long-awaited super vaccine. CSIRO virologist Jenny McKimm-Breschkin said the one-size-fits-all vaccine could come in handy while the public waits for researchers to produce specific vaccines against each individual flu strain. "Essentially what it could do is provide a stop-gap vaccine until clearly matched vaccines are invented," Dr McKimm-Breschkin said. "It all depends on the results of the clinical trial." ...

Researchers around the world, including Australian scientists at Melbourne-based biotech company CSL, have been working on a universal flu vaccine for years. But constant mutations of the virus have made it impossible to create a single effective vaccine. Scientists must reformulate the vaccine every year to keep up with the changes in the virus. The new version would be grown in huge vats of bacterial mixture, with just one litre of liquid providing 10,000 doses of vaccine.

Flu vaccines have focused on two proteins on the surface of the virus, but these proteins continue to mutate. The advantage of the super vaccine is that it focuses on a protein called M2, which is found in the cell membrane of the virus. The M2 protein is found in all types of influenza A and it has barely changed over the past 100 years. Using the M2 protein, the vaccine triggers antibodies that attack the virus as it emerges from the cell. The vaccine does not stop people being infected with the flu, but aims to prevent it from spreading, and to reduce the severity of symptoms.

Although it is too early to say what the effect of the universal jab would be in humans, Acambis director of viral immunology Dr Ashley Birkett said an initial course of two or three shots could provide long-lasting immunity, topped up with booster shots every five to 10 years. "It wouldn't be that one shot protects for life but you would need fewer doses over your lifetime," he said.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter? It is just about pure fat. Surely it should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.

The use of extreme quintiles (fifths) to examine effects is in fact so common as to be almost universal but suggests to the experienced observer that the differences between the mean scores of the experimental and control groups were not statistically significant -- thus making the article concerned little more than an exercise in deception


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