Thursday, August 20, 2009

How Deadly Is Swine Flu?


By Katharine Herrup


It seems like everyone is freaking out about the upcoming flu season and the havoc H1N1 might wreak in America. Secretary of Health and Human Services Kathleen Sibelius says she’s “preparing for the worst.” Experts are worried vaccines won’t be ready in time. Schools are contemplating quarantine situations. And the media is very concerned, judging by all the “Swine Flu – How Will It Affect Your Weekend?” stories each week.

But how worried should we really be? The facts can sound a little staggering: swine flu first hit the scene in late April, and by June 11, the World Health Organization declared swine flu a pandemic. The last flu pandemic declared was in 1967, 42 years ago—the Hong Kong flu, which killed about 700,000 people worldwide. So far, this swine flu is responsible for 1,462 deaths globally. Already, hundreds of thousands of people have contracted swine flu—so many that the WHO has stopped counting. In America, 447 people have died.

A little perspective shows that H1N1 isn’t as scary as it sounds. Pandemic, with all its seemingly lethal connotations, simply means geographically widespread. The common cold, for instance, can always be classified as a pandemic.

So far, the deadliness of swine flu pales in comparison to heart disease, cancer, and other flu pandemics like the Spanish flu of 1918, which wiped out 50 million people worldwide and the Asian flu of 1957-58, which killed about 2 million people. Furthermore, the swine flu appears to be behaving like a regular seasonal flu, with mild symptoms and many full recoveries.

That’s not to say that the seasonal flu is harmless. It’s the eighth-leading killer in America, with approximately 1 out of 5,000 dying from it. But deaths from the flu mostly occur because of complications like pneumonia or underlying chronic diseases like diabetes. Of the 56,326 people that died from the flu in America in 2006, only 849 of those deaths were caused directly by the flu, according to the Centers for Disease Control and Prevention, so if you're young and healthy—or even older and healthy—you're in good shape.

Heart disease, on the other hand, kills about 1 out of 50 people per year in America, which accounts for 26 percent of deaths in America annually. Cancer constitutes about 23 percent of America’s yearly death toll, killing 559,888 people in 2006. The flu accounts for a measly 2.3 percent of deaths. Its death toll is just slightly higher than the number of people killed in auto accidents per year (43,664). Diabetes, stroke, Alzheimer’s, accidents, emphysema and chronic bronchitis, hospital infections, even lung cancer are all more deadly than the swine flu (so far) and the seasonal flu. (Of course, you are more likely to die of H1N1 than being one of the roughly 37,286 per year that die of poisoning and other noxious substances or being one of the 38 randomly hit by lightning.) With what little data we have—remember, swine flu only hit the U.S. about five months ago—it’s a safe bet that you probably won’t die from swine flu.

But the odds are much better that you’ll be sick with it: experts predict as many as 122,883,484 if 40 percent of the population does become infected with H1N1, more than 122 million people might contract swine flu. “What makes flu so bad is that it infects so many people,” says Dr. Martin Blaser, chairman of the Department of Medicine at NYU Langone Medical Center, be it swine, bird, or regular sick-kid-on-the-schoolbus flu.

H1N1 is spreading more quickly than the seasonal flu, in part because most people haven't built up an immunity to this new strain of virus. The flu’s also targeting a much younger, healthier age group. Typically, the large majority of people killed by the flu are those 65 years and older. However, the swine flu has been more prevalent among pregnant women and young adults. Currently, 6 percent of swine-flu deaths worldwide have occurred in healthy, pregnant women, compared with less than 1 percent very rare occurrences with regular flu deaths. Even though mortality will stay low, “the social impacts of the deaths will be greater because it produces death among younger people,” says Dr. Jarbas Barbosa, the Pan American Health Organization’s regional adviser in immunization and vaccines.

In Argentina, 20 to 25 percent of the population has been attacked by the flu over a three-week period. That could easily occur in the United States, where pandemics typically attack between 25 percent and 40 percent of the population. “If we get slammed with this massive burden of flu in a short period of time, even if the mortality rate is .01 percent, you’ll feel more mortality,” says Laurie Garrett, senior fellow for global health at the Council on Foreign Relations. “You’ll have such overwhelmed medical systems that you will have people who will die because the systems are overwhelmed.” (Luckily, the fact that swine flu hit in the off-season gave America time to prepare.)

We can’t know, with 100 percent certainty, how the flu will act once flu season kicks off this fall. “Swine flu is not deadly right now, but we don’t know what it will become,” says Stephen Morse, epidemiology professor at Columbia University’s School of Public Health. “Most believe that this is likely to come back during flu season and be more severe.” But for now, the statistics offer some safety.

And while it’s always good sense to wash your hands and not cough on strangers, there’s no need to break out the protective masks and quarantine kit quite yet. Instead, hit the gym, eat some fiber, and wear your seat belt.


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