Apparently this story's been around for months, but I never saw it. Contrary to popular belief, I don't actually read the entire internet every morning--just the dirty parts.
GF handles the rest, which can be maddening, as I'm often in an in-depth examination of one of the dirty parts when she'll say, across the kitchen table something like, "I think PETA designed those ticks," forcing me to abandon my research and respond, "The hell you talking about?"
In the current case, she was referring to an article on al Jazeera, "The tick that can turn its victims virtually vegetarian."
Over the past few years, doctors in the Southeast US have been encountering patients with a strange and powerful allergy to alpha-gen, a sugar compound found in mammals. Allergic reactions such as swelling, redness, hives, etc. appeared in patients hours after consuming meat or even the gelatin capsules containing their medications.
Thomas Platts-Mills, a professor of medicine and a researcher at the University of Virginia, discovered the connection between lone star tick bites and the alpha-gal allergy in 2006. He had been asked to investigate why some cancer patients were having a severe allergic reaction to the drug cetuximab, even though they had never been exposed to it before.The allergic reaction is so strong that some patients exhibit symptoms when exposed to products that have only come in contact with mammal-tissue products.
It turned out the patients who had a reaction already had the IgE antibody to alpha-gal, which is also found in cetuximab. Platts-Mills and his colleagues began to theorize about the origins of the antibody and noticed that the patients who carried it lived in rural parts of the South and Midwest, where ticks are common.
“It had nothing to do with cancer,” Platts-Mills said. “It had everything to do with rural Tennessee, rural North Carolina, rural Virginia, (etc.). It wasn’t people who lived in the middle of the cities. It was the people who were living in the villages who really had this antibody.”
Okay, another odd bit GF picked up. Interesting enough for a guy who's dealt with ticks and their biochemical pals before (Lyme Disease on three different occasions), but not much more.
Until I'm lying in bed trying to sneak past all my brain's "Let's stay up late and play!" tricks and get some shuteye and the question keeps popping up: Why? I mean, any critter can undergo a mutation and develop a new trick, but what would the evolutionary advantage be? Bugged me so much I had to get up and look up the article myself. And, down the page, came a bit that made the answer obvious.
Lone star ticks have spread beyond the middle South in the last 20 years, having been reported as far north as Wisconsin and as far east as Maine. They tend to follow white-tailed deer, their host of choice, whose population has also been growing across the country, said Susan Little, a professor of veterinary parasitology at Oklahoma State University. The white-tailed deer population has exploded in recent years, with a Cornell University study (PDF) attributing the increase to changes in habitat, "including reversion of abandoned farm fields to forest, and shifts in human population to rural and suburban areas."With our successful depletion of natural predators in the eastern US, we have become the main predator of white-tail deer. Such a narrowing of predator species is a situation ripe for just the sort of accidental c-blocking alpha-gal allergy exemplifies. Put simply, if your main chow source is deer and you serendipitously come up with an antibody that makes the major competition get sick when they chomp down on some venison stew, you've gained an advantage over your rivals for the resource you want.
Makes sense enough. There is, however, an aspect to alpha-gal allergy that I can't fathom: unlike most food allergy reactions, the symptoms of alpha-gal allergy do not present quickly, but can take hours after the patient's exposure to gel caps or sirloin to show up, leading researchers to wonder how many episodes--even of fatal anaphylactic shock--have been misdiagnosed. The most efficacious reaction, if the "goal" is to get your competition off t-bones and into tempeh, would be a reaction so quick and violent that the connection between brisket and barfing was obvious.
Then again, I'm not an evolutionary biologist, nor do I play one on television. Perhaps kossacks with a bit more knowledge of the field can hep me on the reason for the delayed reaction.
In any case, do check out the al-J article. Interesting reading for a Sunday morning, before firing up the grill for some game time burgers and brats.