I had the privilege of attending a seminar yesterday evening presented by author Carl Zimmer for the Department of Organismal and Evolutionary Biology at the University of Massachusetts (Amherst). The title was “Darwin Gets Swine Flu: Celebrating the Origin of Species in an Age of Pandemics.” Zimmer somehow managed to weave together eloquent prose with stunning graphics and a dash of humor. How else would you deftly convey something as sobering as influenza?
I must admit that I have been one of those folks who has brushed aside the hype associated with H1N1. I still wash my hands and take as many precautions as possible without unduly altering my daily life, but I may have to re-think this after learning what Zimmer knew already.
Thankfully, the death toll from influenza pandemics has steadily and dramatically dropped since the global catastrophe of 1918, but even without these periodic spikes, an average of 36,000 people die each year from the regular flu. This year, 10,000 folks have perished from H1N1, in the U.S. alone, since about April. There may be more fatalities yet to come, but we hope not, of course.
Why can’t we seem to conquer influenza? This is where Darwin comes in. Viruses simply evolve to fast for us to keep up with them, at least with our current vaccination technology. We even accelerate their evolution through our global travel, where tropical strains can mix with temperate ones and create new strains within days. The rate at which viruses reproduce is mind-boggling. The rate at which they mutate is staggering. The good news is that the majority of these mutations are fatal to the viruses themselves. Enough mutations survive, however, to create strains resistant to the latest vaccination, or otherwise insulate the virus from our ability to combat it effectively.
Ok, back up a minute. So what do the “H” and “N” and numbers stand for, anyway? “H” stands for hemagglutinin, “N” for neuraminidase, both of which are proteins that coat the exterior of a virus. These proteins are what our immune system antibodies recognize as foreign invaders. The numbers, one through sixteen, represent the known strains of the influenza virus. Where are the rest of the strains? Well, nearly all of them are carried by birds. Birds don’t seem to get sick from these viruses, at least not very often, but of course they have the potential to spread the viruses far and wide with their excrement, and dead bodies (from whatever cause of death).
Zimmer cautioned that “factory farming” of large numbers of poultry birds and pigs in relatively small, confined spaces may mean more flu pandemics in our future. Virus particles (for lack of a better, basic term) are easily passed short distances from one infected organism to another as it is, let alone when they are shoulder to shoulder.
Winter is the time at which we are most vulnerable to infection because viruses sneezed out or coughed out linger in the dry air much longer than in humid air. The viruses also drift farther, and settle on common items like doorknobs and telephones, too. No reason for paranoia here, just caution. After I wash my hands in a public restroom, I use the paper towel to open the door to leave, for example.
Time to switch gears now and encourage you to follow science through Zimmer’s books, website, and blog. The best place to start might be at Carl Zimmer dot com. Be sure to check out his award-winning blog, too, entitled The Loom. What an appropriate name for what Zimmer weaves together in a totally enthralling fashion. Keep up the great work, Carl!