by Rose George
The usual tonic was strong red wine; it revived and was thought to replace the blood the leech harvester had lost from the animals stuck all over her bare legs, which she then removed with hot ash or salt. The occupation paid badly and was confined to the poorest and most desperate, and it was doomed: by mid-century, the native western European leech was getting scarce. Europeans tried to breed leeches, but it was tricky. The first to succeed was M. Béchade of the Gironde in France, who in 1835 invented a revolting method of sending horses, donkeys, and cows into ponds for leeches to feed on.36 When the animals showed an understandable aversion to being cut open and sent into the ponds, they were strapped into a box, wheeled into the ponds, and bled anyway. Elderly horses were often chosen for this fate. It was, wrote Claude Seignolle, like condemning the old horse—who had given years of loyal service—to “two deaths,” and the first was the more horrible of the two.37
But there were fortunes to be made. Béchade did so well his company continues to trade, as Biopharm’s main competitor Ricarimpex. Leech farming was profitable enough that crooks and frauds abounded. In 1856, the French ministry of agriculture condemned the practice of fattening up leeches for sale with old blood (usually from abattoirs) and noted that it contravened Articles 1 and 2 of the 1851 Penal Code. Inspectors were sent to pharmacies to do random leech checks, taking worms, weighing them, then putting them in saline and squeezing them, before weighing them again to see if they had been plumped up with animal blood.38 The increasing rarity of the native leech was reflected in its price: a thousand animals had cost 5 francs ($1); now it was 20 francs and more in winter.
The era of leech import-export and smuggling began. Hungary, Russia, Portugal: they had leech populations to spare, and all gave up their native leeches for profit, and lots of profit. Shipping magnates loved the leech trade, transporting leeches across seas and oceans from Germany, Russia, Hungary, and Portugal to the United States and Brazil. Containers could be tins or pots or glass or cases, but they had to be sturdy, because leeches were canny. Many a ship arrived in port with leeches all over the deck. Brazil’s mania was fueled by the leeching of the Brazilian emperor Pedro I and his wife Leopoldina as well as various Portuguese royals. Slaves, usually young boys from Angola, Mozambique, and the Congo, were trained in leeching and other barber skills, and this made them more valuable. In 1844, as Roy Sawyer writes in an exhaustively researched paper on the Portuguese and Brazilian leech trade, a girl trained in domestic duties sold for 220,000 milréis ($98,300). A slave talented at leeching sold for three times as much. Leeches, meanwhile, sold for 200 milréis ($89) apiece. “In other words,” wrote Sawyer, “at one point the life of a barber slave was worth as little as 500 leeches, and that of a domestic girl for less than 175 leeches. This reflected more on the high price of leeches than on the low price of slaves.”39
Critics of leech mania were surprisingly few. Or perhaps they didn’t survive long enough to record their opposition. An early objector was Lord Byron, whose objections were satisfyingly lyrical. In 1825, parts of a letter written by Lord Byron’s doctor Francis Bruno appeared in the Times and gave an account of the poet’s death the year before. The poet, who had joined the Greek insurrection against the Ottoman Empire, had passed “a very gay day” in Missolonghi when he fell ill. A first attempt at bleeding was canceled because of a commotion in the lord’s bowels. Two days later, after pain in his forehead, seven leeches were applied to his temples, and they took two pounds of blood. “I perceived,” wrote Bruno, “that his Lordship had a very great aversion to bloodletting.”40 “Have you no other remedy than bleeding?,” the patient asked. “There are many more die of the lancet than the lance.”41 This is admirable wordplay from a man on his deathbed, but it didn’t stop the doctors: they thought blood should out, and they got it. “Come,” said Byron toward his end, “you are, I see, a damned set of butchers. Take away as much blood as you will but have done with it.”42 They did, and he died.
In 1827, a doctor named Joseph-Marie Audin-Rouvière had published a “No more leeches!” anti-bleeding polemic. It was a “murderous system,” wrote Audin-Rouvière, whose prestige was “almost inexplicable.” He described the visit of a typical doctor. He does not consult his patient or ask him about symptoms but, from the threshold, cries, “Leeches! Leeches!”
“How many?”
“Sixty, eighty.”
“But the sick man has no strength, he is eighty years old.”
“The leeches will give him strength!”
He tells of a Dr. Frappart who, during the course of one patient’s sickness, applied eighteen hundred leeches (so that the course of the sickness probably ended in death); and of the case of Monsieur Martainville, a newspaper editor, whose gouty fingers received five hundred leeches. “Everybody knows that M. Martainville still has gout.” If each leech took an ounce of blood, wrote Audin-Rouvière, then a patient could lose twelve pounds of blood. A Broussais leeching could take 80 percent of a patient’s blood volume, putting them at risk for the most severe category of traumatic hemorrhage, one that usually ends in death. Audin-Rouvière hoped that justice would be done to Broussais, but it wasn’t.43 In the decades after his death in 1838, leech mania subsided, to the gratitude of leech gatherers and leeches. An obituary of this “immense celebrity” mourned the loss of the great man to medicine. Broussais did leave something of a legacy: paisley was probably inspired by his leech mania (it was actually Persian), and his questioning of humoral medicine was useful, though his conclusions could be murderous. This “ardent defender of inflammation and leeches,” as an obituary writer described him,44 had also overseen an animal hunted to extinction in many countries and lied about how many patients had survived his theories.45 But there are hospitals named for him, in France and Italy, for Broussais the most bloody and bleeding.46 There is no memorial for the millions of leeches his bizarre theory wasted or the patients his theory killed.
* * *
The video is over. My nerves wake up along with my disgust mechanism, because next is the tour of the tanks, and leech wrangling. For an animal that biologists describe as rather simple, the leech needs complicated handling. Biopharm’s leech raising is done over three large rooms, each kept at a different temperature. The further in we go, the further along the path of the leech to becoming a hospital device, the colder it gets. All the tanks and equipment are built to exact specifications, most of it devised by Carl. It is the engineering and the precision that keep him at Biopharm, not the leeches. Everything here, he says with pride, is bespoke.
The first room is kept at 78.8 degrees Fahrenheit. It gives the pleasurable jolt that a winter walker gets entering a tropical hothouse, a sudden wash of heat. I take a photo though the sight is just dozens of tanks draped in white muslin. Carl notices. “You can take a picture of the room but not of the tanks.” Breeding leeches is a sensitive process of feeding and starving and warming and cooling, and leeches can be spooked even by the noise of a smartphone click. The tanks are where leeches are born, by the happy meeting of any two of them: leeches are hermaphrodites and very flexible. Carl lifts a corner of muslin covering a tank and picks one up. It’s a European and surprisingly beautiful, its belly striped with iridescent gold and green. Even Carl, the sober engineer, admits, “The colors are quite nice. If you see anyone else’s leeches, they’re not as nice as ours. I select them for color.”
Elsewhere are the buffalo leeches. They are kept for animal use: cats can be leeched because of polycythemia vera, a condition of excess hemoglobin in the blood. Dogs are often leeched to relieve swollen or infected ears, a problem particularly common in French bulldogs. Carl thinks Biopharm supplies leeches for 90 percent of French bulldogs with cauliflower ears, as aural hematomas are nicknamed. I like that statistic, but I am not sure it can be backed up. Carl says the buffalo costs an arm and a leg, an appropriately physical metaphor, but like the pharmacists’ leeches of old, rented, squeezed, and re-rented, buffaloes can be reused. Also, buffaloes get hungri
er more quickly than medicinal leeches so they can be used more frequently: even after feeding to satiety on a cat, they will be ready to eat again in six to eight weeks. The European medicinal leech spends a year digesting one meal.
The menu at Biopharm is always black pudding. In the two years it takes to raise a European leech for medicinal use, it is fed sheep’s blood served in sausage casing every six months. Biopharm used to feed its residents with cow’s blood, which was more successful. The leeches ate it more readily, and one cow held the blood volume of ten sheep. But bovine spongiform encephalopathy (BSE) has ruled out cow blood, for leeches and humans.
Carl points out an immobile leech on the bottom of the tank. “That’s what they do in the wild. When they feed, because they have a huge reserve of blood, they’ll bury in the mud or moss.” He describes the leech as a sort of oil tanker: all its reproductive organs are on the front where the cab would be. “The central organs are on its side. It’s got two hearts, one on each side. The bulk of it is storage.” A fed leech can swell to up to five times its body weight. A small leech can expand eightfold. Carl sticks his finger in the water and a leech immediately appears. “He’s sniffing around now.” Actually, it’s more of a tasting: Carl thinks they sense the sugars and oils in the skin. He picks one up but isn’t bitten. “I’m not very attractive to leeches.” A bigger problem is leeches biting each other. They can digest at different rates. “Maybe one leech has shrunk down to three hundred milligrams and it’s in a tank with a leech that is three or four grams.” That is a recipe for murder: a big hungry leech will eat from a small hungry leech, and sometimes the biting can be fatal. The best method for peace among leeches is to adjust the temperature so they are half asleep and half awake. The safest leech is a spaced-out leech.
Biopharm also experiments with tank size to give leeches the optimal amount of exercise. Carl is tank builder, leech grower, and personal trainer: leeches have to be exercised twice a day. It’s not complicated, as training programs go. “I’ll go and pick one up and put it at the other end of the tank.” It will swim, and it can lose weight quite quickly. Sometimes it gets more exercise than Carl bargained for. Their most annoying talent, he says, is for escape, even from Biopharm’s tanks. He has often arrived home to find some attached to his ankles. “I’m usually surprised if I don’t find ten leeches in the footwell of my car. They stick to your shoe and then they dry out.” He says this, and we all look at our feet.
Leeches can shift. In a race between a slug and a leech, who would win? It depends on the conditions and climate, says Bethany Sawyer, but leeches can move faster than expected. “A lot of people assume that the leech’s relative is a slug because they’re black and look like that. So we have people who ring up wanting them for weird and quirky photo shoots.” Once, it was a fashion student. Often, it is someone who wants to do a “wacky” promotion of various things, events, places. “And they get the leeches thinking they are going to be really slow and they’re going to have all the opportunities in the world to take the perfect picture, they’re going to be able to set them down, to tell them to sit and stay.
“And that’s it,” says Carl. “They turn the lights up and whoooomph! Off they go.” How far can they travel? “Anywhere it’s damp. So anywhere in Wales, really.”
When they swim, they come fast and beautifully. On land, leeches move by suction: they suck with the front sucker, then the rear, and that is their locomotion. It is an efficient but not elegant movement. (It is nothing like earthworm locomotion, which is done by peristalsis-style burrowing, in waves.) But in water, they are different. They are sinuous. “By flattening and manipulating their bodies into wavelike patterns,” write Kirk and Pemberton, “leeches are capable of swimming at speed and with an elegance few other creatures can rival.” Leonardo da Vinci drew leeches in his notebooks in an attempt to understand the physics of their movement.47 The motion is dorsoventral, as done by whales, dolphins, and eels: up and down, not side to side (think a butterfly stroke, but done by an Olympic athlete, with grace and power).
It doesn’t matter how good a swimmer a Biopharm leech is. It will be packaged in gel and sent to a hospital pharmacy, and sooner or later—its work done—it will be killed. In 2004, the US Food and Drug Administration (FDA) gave Hirudo medicinalis an unclassified status as a marketable medical device.48 Single-use only: all leeches employed in hospital settings must be exterminated with alcohol solution once they have fed and dropped off. This seems ungrateful, but a filled leech is a biohazard. Leeches can transfer blood from one person to another. “They’re worse than that,” says Carl. “They’re a needle that can walk.” Biopharm sells a special euthanasia kit called Nosda to dispatch the leeches humanely. This includes the alcohol required, various pots, and, with misplaced kindness, “leech-friendly forceps.”49
The leeches in the cold room are almost hospital-ready. They have had four feeds in their lifetime and been starved for six months. If he’s lucky, says Carl, he can get a leech from birth to a hospital pharmacy in two years. But usually it’s about three. The starving is because a hungry leech, when applied to a human, is an efficient leech. We are not allowed into the final room, as it is bathed in UV light to make the leech as sterile as possible. Nor do we see the packing: leeches make their onward journey in a proprietary polymer gel. There is skullduggery in leeching: when I ask Carl if there is any corporate spying, he won’t answer, except to say, “We don’t need to. No one has a yield like ours.” Ninety percent of the leeches born at Biopharm grow up to be walking needles. It helps that they are flexible, with a tolerance of temperatures from 23 degrees Fahrenheit up to 104. If it’s hotter, they travel with ice chips. They have to arrive in good order: they have work to do.
* * *
And one of them struck the slave of the high priest and cut his right ear. But Jesus said, no more of this, and he touched his ear and healed him.
—Luke 22:50–51
Amputated ears are harder to fix than the Bible maintains. They are filled with tiny blood vessels, so when they are torn off—the medical term is “avulsed”—it is difficult to reattach them. It is a tiny tapestry torn in half, but the tapestry is made of hairs whose diameter varies from 0.3 to 0.7 millimeters (a human hair is actually thicker). Every tiny thread must be reattached and must work. It is fiendishly complicated. As three doctors wrote in one paper, “Cases of successful microvascular reattachment of totally amputated ears have been conspicuous by their absence.” This paper appeared in 1987 and caused a sensation. You wouldn’t know why from the title, which was “Microsurgical Reattachment of Totally Amputated Ears.” Nor would you know why from the images. They are graphic, showing an avulsed ear, then a reattached one. They do not show the reason the paper became as renowned as one of its authors, pediatric surgeon Joseph Upton.50 The reason was leeches.
In 1985, a three-year-old boy from Massachusetts named Guy Condelli had his ear bitten off by the family dog.51 He was taken to Boston’s Children’s Hospital, where his surgeons included Joseph Upton. The surgeons proceeded as they usually did with amputated ears: the detached ear was examined under a microscope in the operating room. Several sets of blood vessels were identified, measuring 0.2 to 0.5 millimeters in diameter. “It was impossible,” wrote the paper’s authors, “to distinguish arteries from veins.” The boy was given a general anesthetic and the ear was stitched back to its rightful place. But it began to turn blue. The blood was being pumped into the area by the arteries, which are more robust and quicker to recover, but the veins weren’t working and the blood couldn’t be pumped away again. The blood was stuck, dark and ominous through the skin. During his operation, the boy had been given 5,000 units of heparin, a powerful anticoagulant, to loosen the congestion. It didn’t work. By day five, as the images show, the ear looked black. The child was in trouble.
Joseph Upton had worked as an army surgeon during the war in Vietnam. He had heard about leeches and maggots being used. “I started calling round the country to
my friends,” he told a reporter, “trying to find some hungry leeches.”52 This was unlikely to be successful. In Carl Peters-Bond’s words, American leeches “are rubbish.” The Asian medicinal leech is 25 percent less effective than the European, in Carl’s estimation, but the American variety is twice as bad. Its anticoagulant doesn’t work as well, and Upton needed the most powerful anticoagulant he could get. So Upton needed a European medicinal leech and the United States didn’t have any. Nor were leeches licensed to be used as medical devices. Upton eventually found Biopharm, founded only the year before by Roy Sawyer, and ordered some of its products. I ask Bethany how they got to Boston. “Flown. The pilot took them.” Imagine this: a pilot flying over the Atlantic who has to worry about storms and turbulence and keeping three hundred people alive, and he also has a box of leeches behind his seat. That would be a fidgeting pilot.
The leeches arrived safely and were placed directly on the congested tissue. Upton described the procedure in his article. “When they were engorged, they would fall off the ear. New ones were applied when discoloration occurred. Following initial application, the color immediately improved.” Or, as Upton told a reporter more plainly, “The ear perked right up.” It perked, it pinked, it was saved.
For a paper that was describing a revolutionary and extremely successful procedure, it is oddly reserved, beyond the usual dispassion of scientific journal writing. Graphic pictures of ripped-off ears are shown but not the leeches that saved them. There is no triumphal trumpeting of the first successful use of leeches in decades. Instead, the authors write glumly, their use was “not new.” Nothing to see, no big deal that multisegmented annelid worms that most humans find revolting had just been let into the most sterile environment possible and performed a revolutionary act of anticoagulation on a three-year-old boy who would now have two working ears.
In a way, this self-undermining was justified. A pair of Slovenian surgeons had rehabilitated the medicinal leech in the 1960s.53 But leeches hadn’t been used in an American or British operating room for decades. Thirty years after Guy Condelli’s operation, the leech occupies a peculiar place in modern life. To the general public, it is simply disgusting. They think leeching is “evil quackery,” says Bethany Sawyer, and that it belongs in the Middle Ages along with pestilence, boils, and Blackadder. In 2016, the Olympic swimmer Michael Phelps was revealed to be a fan of “cupping,” a technique popular across the world for centuries.54 Cupping applies cups—glass, usually, but cow horn will do—to the skin. A flame is lit, then extinguished, and a vacuum created inside the cup is supposed to draw blood into the tissues and provoke an anti-inflammatory response. It’s meant to improve blood flow. The sight of dark red circular marks on Michael Phelps caused derision. One science writer tweeted: “What next, leeches?” A New Yorker writer, wanting to convey that someone thought something was pointless, wrote, “It would be as useful as applying leeches to a head wound.”55 Guy Condelli’s ear—a head wound—shows that this is wrong. But the leech is still a symbol of the ignorant and old ways, when a woman was known to be hysterical because her womb wandered around her body, and the application of half a mouse to a wart was thought sensible.56
