Ugly Little Suckers But They Make Great SurgeonsHeidi Dawley
Tiny Biopharm (UK) Ltd. is nestled among hedgerows and sheep pastures in a southern Welsh valley eight miles from Swansea. The countryside is known for farming and livestock, but Biopharm, housed in a 3,500-square-foot shed, produces a different crop: leeches. Its motto: "The biting edge of science."
That's right, leeches--those repulsive worms that doctors for centuries used for bloodletting. Humphrey Bogart best described the way most of us feel about them in The African Queen: "The filthy little devils....If there is anything in the world I hate, it's leeches."
Not everyone agrees. Some people are learning to love them. Leeches, it turns out, play a critical role in human medicine. Doctors reattaching severed body parts or grafting tissue use leeches as a last resort if the operation appears likely to fail. After surgery, veins slowly grow back together. But in the meantime, blood can clog the reattached tissues when the surgeon has succeeded in getting inbound arteries to work before outbound veins. That's where the leeches come in. They suck out excess blood, and they inject anticoagulants that keep their bites bleeding for up to 10 hours after they've dropped off. Doctors might apply from 1 to 1,000 leeches over a five-day period. The bite of each three-jawed leech looks like a tiny Mercedes-Benz star.
The turnaround for leeches came in Boston in 1985. A German shepherd had bitten off a boy's ear, which was surgically reattached, but the operation was in danger of failing. The doctor applied leeches and saved the ear. Now, with the growth of microsurgery, leeches are a cash crop. No one knows the size of the market or even the number of producers, though there are probably no more than a dozen around the world.
NONRECYCLABLE. I've come to visit Biopharm in Hendy, Wales. The lean-to shed against a brick wall is advertised as the world's largest commercial leech farm and is next to the big white Victorian house of Roy T. Sawyer, 54, the company president. The family-owned business, which employs 13, sells 50,000 wriggling bloodsuckers a year to hospitals in 27 countries. The company won't release its financial figures, but leeches go for up to $13 each in Britain. Biopharm, whose leech sales are growing 20% annually, offers 24-hour delivery. Leeches are killed after they've fed rather than reused, for fear they'll transmit AIDS or other blood diseases--although there's no proof they do so.
"Doctors are reluctant to try them, but once they do, they are hooked," says Marian E. Gower, head of leech sales. Hard to believe, but patients are hooked, too. "I've never had a person refuse," says Henk Giele, a plastic surgeon at the Radcliffe Infirmary in Oxford. Local resident David Hudson, 29, who had 40 leeches applied to a tissue graft on his hand injured just before Christmas, says: "The thought of having sluglike things feeding off me was not nice. But in the end, I even named the first two--Blinky and Perky." His worry: They sometimes sneak off in search of another meal. "When a leech goes missing, you should hear [the patient] scream," says Giele.
Although there are 650 species of leeches, Biopharm concentrates on just two--the European Hirudo medicinalis, the Blinky and Perky variety, used for both patients and research, and the Haementeria ghilianii, or giant Amazonian leech, used only in research. Up to 80,000 leeches are stored at the farm, in 120 aquariums, countless buckets, and a couple of containers from Selfridges' food hall in London.
I go first to the cold room, where 22,000 leeches are kept at around 50F to slow their metabolism. After not eating for about a year, they're ravenous and ready for medical emergencies. "Watch where you step," warns Jim Sims, general manager. "They do get out. I've been bitten dozens of times." Sure enough, a few adventurers squirm near my feet. Lucky for me, they're slow on cement. But when G. Carl Peters, breeder and caretaker, puts his bare hand into the aquarium, the leeches dart around wildly. No lunch for them, however; Peters removes his hand. They won't eat until they hit the hospital. About three inches long now, after a good gorging--those not awaiting hospital duty are fed every 3 to 12 months on warm pig's blood in a sausage skin--they grow fivefold. Residents of the cold room require little care beyond a little fresh water now and then.
A TASTE FOR BACH. The magnificent gray-brown Amazonian leech is raised in the warm room. Peters, who keeps pet lizards and cockroaches at home, has a soft spot for these graceful swimmers, which can nearly double in length, to 18 inches, when full. He increased the number of Biopharm's Amazonians, from 11 in 1992 to 3,000 today, in part by playing classical music for them, he says. That may not be as wacky as it sounds. Peters says music causes vibrations in the leeches' artificially still world. "When I play it, they undulate at the bottom of their aquariums, almost in time to the music." The leeches' top pick: Bach.
There is something fetching not only in their musical tastes but in the way the leeches keep their babies snuggled up to their bellies for six weeks, gently curling their sides around the offspring for safekeeping. One mother I touched felt like slimy Velcro--and didn't bite. Well-fed leeches don't, Peters says.
Set up in 1984, Biopharm also patents chemicals from leeches and licenses them to pharmaceutical houses for use in developing drugs, primarily to fight blood diseases. "Animals that evolve to feed only on blood evolve a whole range of chemicals to deal with blood," says research director Robert B. Wallis. Biopharm has high hopes for hementin, a clot-busting chemical extracted from the Amazonian. The drug is in clinical trials. Biopharm is also working on leech derivatives for drugs to treat thrombosis, heart attacks, and strokes and hopes to find a compound for anesthetics.
"Secretions from bloodsucking animals are to cardiovascular disease what penicillin is to infectious diseases," says Sawyer, who may diversify into other bloodsuckers that feed on humans--bedbugs and vampire bats, for instance. As a boy in South Carolina, Sawyer became interested in leeches when he found one on a turtle. With a degree in zoology, he came here to study leeches in a renowned program at the University of Wales-Swansea. For a while, he opened Biopharm to the curious, but people came in such droves he had to shut the door.
As I shut the door on Biopharm, I carefully check my ankles for freeloaders. While I'm glad to know that Blinky's and Perky's relatives hungrily await me should the need arise, I don't want to provide this year's dinner.