Many headlines this week have covered the Swine Flu, a bug that has killed 80 people in Mexico alone. With little respect for borders, the flu has quickly spread to the United States, Canada, Europe and New Zealand.
What should you make of this alarming news?
Health officials are concerned by the appearance of this new swine flu because the jump from pigs to humans recently occurred, meaning people have no immunity to the bug, and the flu now appears capable of effective person to person transmission. That combination means the virus has pandemic potential. The last global epidemic occurred in 1918 during which 50 million people died. The actual number is a little hard to pin down, but experts give the range from 30 to 100 million as the final casualty figure; 50 million is the most often quoted. In any case, that flu killed more people than all previous outbreaks of the Plague, and more than the number of people who died in WWII. The potential for millions of deaths is what gives urgency to our response to the latest viral assault.
We could easily dismiss the warnings as a bit hysterical if we remember the 1976 outbreak of another swine flu. In that outbreak the first know victim, a healthy and robust soldier at Fort Dix, New Jersey, died within 24 hours of contracting the disease. Soon 500 of his compatriots fell ill. Given the aggressive nature of the infection, the federal government created an emergency inoculation program under which about 40 million Americans were given vaccines. Of those millions several hundred developed Guillain-Barré syndrome, a nasty induced-autoimmune disease in which the body attacks is own nervous system. The inoculation program was discontinued. An epidemic never developed.
More recently we had, and still have, the scare of H5N1, a bird flu originating in parts of Asia where people and poultry live in close quarters. This deadly virus appears to kill more effectively than any flu that has come before. Once the virus jumped from birds to people, little time passed before it could be transmitted from person to person, although the virus seems to pass between people inefficiently. That is, until a mutation removes that last barrier to a global outbreak. H5N1 cases have been confirmed in the United States, Asia, Africa, the Pacific, Europe and the Near East, Indonesia and Vietnam, but that global reach is not what is really eye-catching about this virus. Overall mortality in reported H5N1 cases is approximately 60%. To put that in perspective, the analogous number for the 1918 flu was 2.5% to 5%. Pause a moment to think about that. This virus is potentially 10 to 30 times more deadly than the virus that killed 50 million people. The incredible lethality of H5N1 led to a massive and concerted global effort to wipe out the reservoir for the virus by killing tens of millions of infected birds. The rapid and massive global response seems to have kept the virus at bay for now.
So given the seemingly false alarms with the 1979 swine flu and the recent arrival of H5N1, why should we believe health officials that this latest swine flu will cause us harm? Primarily because those outbreaks were not false alarms. Inoculating 40 million Americans was likely enough to prevent epidemic spread of the disease even after the program was discontinued. Without the vaccine program, the flu may well have infected a wide swath of the populace. Equally true, the massive globally-coordinated response to H5N1 with the destruction of millions of birds almost certainly prevented a pandemic, along with the fortuitous characteristic that the virus transmits poorly between people. The absence of pandemics in both of these cases does not mean that officials overreacted; instead it means that the actions they took likely prevented a much bigger outbreak. While proving a negative is difficult, prudence would dictate that we do not dismiss these examples simply because the actions taken effectively prevented a pandemic.
So, if we must take the new swine flu seriously, how much of a threat is it to us? To understand that we have to take a quick dip into the world of epidemiology. Scientists describe a disease using two primary characteristics: pathogenicity and virulence. Even the experts don't agree on exactly how these terms should be defined, but really they are easy enough to understand.
PathogenicityHow easily a germ causes disease, and how readily it spreads, describes pathogenicity. If just one exposure to a few germs makes someone ill, that bug would be considered highly pathogenic. In popular use we often describe a pathogenic bug as being contagious -- that is, the virus or bacteria readily causes disease and easily spreads.
Virulence
How severe the symptoms are once somebody gets sick describes a bug's virulence. In the most extreme examples of virulence, infection often leads to death. In that case we also discuss a bug's lethality -- which describes how many people who contract the disease die from it.
As an aside, not everybody would agree with my definitions. Some use virulence like I'm using pathogenic, or use the two terms synonymously.
With those two primary characteristics of pathogenicity and virulence we have four significant possibilities when we encounter a new bug: highly pathogenic and highly virulent; highly pathogenic and mildly virulent; mildly pathogenic and highly virulent; and mildly pathogenic and mildly virulent.
It could be, for example, that millions of people fall ill from a highly pathogenic virus that spreads rapidly through the population, but the symptoms of the disease are mild, say a runny nose and sore throat. That would be caused by a bug that is highly pathogenic but mildly virulent.
Or we could repeat what happened in 1918, where millions get sick, but instead of runny noses as the symptom, 60% of those infected die from hemorrhaging, dehydration, fever or massive organ failure. That outcome would be caused by a highly pathogenic, highly virulent virus.
With that knowledge in hand, we can now evaluate better for ourselves the threat of new viruses as they appear. You can now see the global concern for H5N1, one of the more virulent viruses described by scientists. Fortunately, because it passes poorly from person to person, for the moment at least, the virus is only mildly pathogenic -- it does not easily cause disease when one person exposes another to the virus. Yet. The real concern is that just one minor mutation could easily remove that barrier to transmission. In fact scientists believe that is exactly what happened in 1918. If that happens now with H5N1, we could see a pandemic that rivals 1918 in numbers of dead.
And you also can now understand the concern about the new swine flu, dubbed H1N1, an entirely new virus that is a mixture of bird, pig and human viruses. Unlike its cousin H5N1, the new virus indeed passes quickly and efficiently between people, even those never exposed to pigs or birds. So we know the bug is highly pathogenic. Unfortunately, H1N1 is also proving to be highly virulent, killing healthy young victims at alarming rates. We now face a virus, therefore, that is in the most lethal category, similar to what the world saw in 1918: highly pathogenic and highly virulent.
So do not dismiss health warnings. Do not pretend that officials can be ignored because they earlier issued "false alarms" that in fact were not. This is serious business. There is certainly no need to panic, but the potential threat is real. Therefore, the appropriate response is to be vigilant, to take prudent precautions, and to heed warnings issued by health experts.
You might, however, wish to dismiss those who claim that flu warning is a liberal conspiracy to push Kathleen Sebelius through the senate as Health and Human Services Secretary. Her nomination is being filibustered in the Senate by those who claim she is a "radical abortionist." If that conspiracy seems a bit over the top, Tony Perkins, President of the Family Research Council, has explicitly claimed that liberals are "scheming" to use the health "scare" to win confirmation. I suspect that Mr. Perkins would feel differently when infected H1N1. The bottom line is that Republicans are preventing the government from installing a leader at our national health agency in the midst of a potential crisis, all for short-term political gain. That parliamentary maneuver is the worst kind of cynicism one can imagine. Senate Republicans are using our health as a political football, ignoring the real threat from H1N1.
Follow Jeff Schweitzer on Twitter: www.twitter.com/JeffSchweitzer
I think I can help with that messy figures whole thing since I saw a very clarifyng TV program with the Mexican Health Secretary yesterday.
It turns out that there are two different counts. The initial one was based mostly in suspected cases plus few confirmed cases. They took all people who had died of likely influenza-related pneumonia nation-wide and then they added the few confirmed cases. The reason they had so few cases confirmed is that the only way to test them was sending samples to Atlanta, and that was taking so long
Finally yesterday they were able to implement a laboratory capable of testing in Mexico. The first count is not valid anymore. By testing, they have dismissed most of the suspected deahts, that's why the death number have decreased.
These means we should forget all figures we had before.
You see Mr. Schweitzer why I considered the death rate you speculated so irresponsible? That was based on numbers which are at this point NO LONGER VALID.
The number of suspected deaths in Mexico is now 159. If you want to cite WHO's recent statements that they confirm fewer than that, that is reasonable -- we probably can't know for sure right now. But then you can't turn around and ignore the significance of the WHO raising the threat level to 5. Picking and choosing citations is not intellectually honest.
Even if everything you said were true, your conclusion would still be wrong. If the numbers cited in my blog turned out to be wrong (and they are not), or overtaken by events with new information, that would in no way make the blog irresponsible --as long as I cited the best sources of information at the time of writing; which is exactly what I did.
So, no, I do not see how my speculation of death rates was "so irresponsible." Instead, I would claim any attemp to minimize the potential threat is -- just as it would be to exaggerate the threat.
Deaths regularly referred to the 1918 pandemic is 20- 50 millions (not 100 million) That was not the last global epidemic. The 1957 pandemic killed only 70,000 in the US and the last one in 1967, killed 38,000. You insist on the potential to match the 1918 pandemic, but you don't mention at all the main reason the later were milder was the world had developed antivirals and antibiotics. Besides, the 1918 pandemic began in the fall and this makes a huge difference. Not to mention vaccination, which will prevent more future outbreaks
Then you just keep up SPECULATING, considering just the most terrifying scenarios. You can't talk about a death rate at this point. You even compare it with the 1918 death rate. Only 7 deaths in Mexico are confirmed by testing (the rest are suspected) Even considering all of them (most should be) you can no figure a death rate out of 2,000 cases and compare it with millions of cases in 1918 after months of evolution.
You say H5N1 is "one of the more virulent viruses described by scientists". Was it ignorance or just simply a lie? .Scientist, WHO included, have been very clear on this. There's no way to know that at this point
You said there's no need to panic. As you clearly encourage to the opposite, you're being absolutely incongruent. You wrote one of the most unproffesional articles I've read during this contingency. Too sad.
My article was written to provide people with a background on the problem, and some tools to evaluate the news. Nobody other than you so far has considered the article to be inflamatory. It was certainly not meant to be so. Discussing possibilities is not equivalent to making a claim that those scenarios will play out. But it would be terribly irresponsible to ignore those possibilities. If anything is sad here it is that you have attempted to create conflict where none should exist.
As to the 100 million figure, I know there's documentation about that. I specified the 20-50 millions figure is the "regularly" referenced. By far, I'd add.
I was accurate when I wrote 7 was the confirmed deaths. If you see the date and hour I posted, that was the updated information at the time. Actually, right now there's more than 80 confirmed deaths. Still, that number is far of being statistically significant
in order to be compared to the millions 1918 figure and to stablish a reliable death rate. That was initially my idea
Finally, I'm very curious on why you didn't say anything about my most agressive point. The one in which I say your statement "H5N1 is one of the more virulent viruses described by scientists" is absolutely false.
Thank you again for replying and best regards.
The truth is we should *always* take the flu seriously. Every time a person with the flu goes to work or school, they are potentially killing someone down the line. Over 35,000 people die from the flu each year in the US. Over 50 American kids died from it last year. So, really do consider whether that report *has* to be filed today, even though you or your kid has a 100 degree fever...
Public health officials are trying to stem the rate of infection so that swine flu has less chance to kill people at high risk (elderly, babies, immuno-compromised) and to give it less chance to mutate before we have a vaccine. That is good and we should help them out. Follow all instructions if and when it shows up in your community. Wash your hands a lot. Know the basics of home care (in summary: watch closely for dehydration and respiratory distress).
Beyond that, there is absolutely no need for the level of alarm that people are starting to show.
I clearly stated there is no reason for panic. Perhaps I should have put that in bold face large font? I agree completely that the level of alarm is not comensurate with the data in hand; but I also agree that public health officials should be acting aggresively. That is the balance we have to reach.
In one paragraph we read that the 1918 flu pandemic had a mortality rate of 2.5 to 5%:
"Overall mortality in reported H5N1 cases is approximately 60%. To put that in perspective, the analogous number for the 1918 flu was 2.5% to 5%."
But in another paragraph we read that the 1918 flu killed 60% of its victims:
"Or we could repeat what happened in 1918, where millions get sick, but instead of runny noses as the symptom, 60% of those infected die from hemorrhaging, dehydration, fever or massive organ failure."
So which is it?