Leeches!

    Recently a friend of mine posted a video on the social networking site Facebook of a scene involving leeches and the TV show Fear Factor. Leeches, as you all can guess by me taking about them in this blog, are invertebrates that almost exclusively feed on blood of other organisms. They are slippery, they are slimy, and for most people the first thing that comes out of their mouths when they think or see leeches is "Gross!". In fact, I'm one of those people too...even though I respect them, they are on my "yuck" list, mostly because they feed on blood which bothers me more than the leeches themselves! Fear factor loves to use invertebrates in their show, from roaches to scorpions to worms because most people have an "ick" factor to any invertebrate, so having leeches was a new addition to their arsenal.
    In the show's episode the woman of the couple has to sit in this tub filled with leeches for 30 seconds, let them attach to feed, and then get out so her partner can then bite them off of her. He then has to eat 30 of them, and then she has to eat another 30. Talk about not the most appetizing meal one can have, and for most people it would be scary. The link to the video is here on Hulu. Most people's reaction after watching the video is why on earth would we have such things, and are leeches really good for anything other than sucking blood of reality show contestants?

Image of a medicinal leech, Hirudo medicinalis, from Wikipedia.com

    The answer is yes leeches have been around for a long time and have their place in the ecosystem, but what most people forget is that leeches actually were a pretty "normal" thing for people to see in Western culture because they had a big part in our medical history. Medicinal leeches, which were likely the leeches used in the TV show, were used to "bleed" patients that were sick and was thought to help remove the toxins affecting their health. In fact, the large amount of leeches they got for the show is likely because they were being bred for modern-day medicinal uses, and were probably fairly hygienic to eat as far as leeches go (the worst thing that can probably happen is the bites from leeches get infected later on, but for the most part the bites are fairly harmless). Wikipedia has a nice article about the use of leeches in the past for medicine here, and there is a long and neat history about how using them came about.
    Even though we don't do bleeding in medicine anymore, the use of leeches in modern surgery is bringing leeches back into the medical limelight. Leeches have an anti-coagulant (blood thinner) and feed without really being noticed (they anesthetize the site so you don't feel the pain), which makes them good candidates for increasing blood flow to delicate structures that are being attached or re-attached, or wounds that have difficulty healing. For example, here is a link to an interview with a doctor at the University of Mississippi Medical Center who talks about using leeches for wounds.
    So, yes the video of the a tub of leeches seemed nasty and would lead one to wonder why we want such creatures around us. However, these little guys do have a place in our world and even have useful applications to modern society, especially outside of fodder for reality tv!