THAT MOST SINGULAR AND VALUABLE REPTILE1
Six seconds. Perhaps ten. Twelve, if it is cautious or dopey. After that, the jaws will activate, the hundreds of teeth will engage, the leech will begin to eat, and its meal is your blood. Are you wading through a tropical pond in fierce humidity? Have you returned to your guesthouse to find with horror a passenger on your leg? Are you Humphrey Bogart, tugging the African Queen and Katharine Hepburn through a brown river, cursing the “filthy little devils” that cling to you? Possibly (except the last). But you are equally likely to be in a sterile room of a modern hospital, tended to by nurses who attach these bloodsucking animals to you without a shiver. You accept them equally calmly, because it has been explained to you that these leeches may save your breast, or your finger, or your ear, or your life.
Less than half a mile from the busy M4 motorway, in the southwest of Wales, there is a walled entrance off a road whose Welsh name I can’t pronounce, and a small sign saying BIOPHARM. A long and winding driveway passes sheds of unclear purpose and ends in a small yard beyond an imposing cream-colored manor house. The view is unexpected: I can hear the motorway, a distant roar, yet here is a quiet landscape of green fields stretching away with no apparent end. The nation’s only leech production business looks like a health farm. Which I suppose it is.
Biopharm was founded by Roy Sawyer, an American zoologist transplanted to Wales. Its name is as broad and generic as its business is specific: it is one of fewer than half a dozen suppliers of medicinal leeches in the world. My hosts are Sawyer’s daughter Bethany, a young woman with a mild Welsh accent and a stern demeanor who is Biopharm’s manager, and her colleague Carl Peters-Bond, a fair man who is what grandmothers would call “cuddly.” They may revise that when they learn that one of his job titles is “leech-growth technician.” Carl is also a practiced Biopharm guide, as well as a retriever of visitors who, given how little signage there is, must inevitably wander into the narrow corridor and wonder if they are in fact in buildings that house a globally renowned supply of medicinal leeches or in someone’s garage.
The reception room is furnished with a large table, a library of leech-related and zoological books, and several ceramic jars in a cabinet, identified by their ornate lettering spelling out LEECHES. These jars were used by apothecaries who sold leeches and sometimes rented them in the high times of the leech industry, from the beginning of the nineteenth century to the early twentieth, a period known as “leech mania.” The mania was for bloodletting, or “the taking of blood from a person with therapeutic intent,” in one description, which had been used for a few thousand years to cure ailments ranging from headaches to near hangings.2 There was hardly any disease or condition for which bloodletting was not thought useful; it was even used to treat severe bleeding. For most of human history, we have preferred to remove blood, not add it. By the end of the nineteenth century people still believed so powerfully in the force of bloodletting that they “were in the habit of coming to be bled at their own request, just as they now apply to have their teeth drawn.”3 Bleeding was done by opening veins with lancets and knives (and earlier with stones, fish teeth, or whatever could cut4), but a leech was kinder, sucking its blood from the capillaries, not veins, and providing its own natural anesthetic.5 By the twentieth century, bloodletting and leeching had fallen from favor with the rise of better surgery and medicine and germ theory. By then the leech had also been harvested almost to extinction from its natural habitat in most of Britain and across much of Europe. Although leech fans are always hopeful of finding undiscovered populations, the known habitats of the British medicinal leech, now, are wetlands near Dungeness, some ponds in the New Forest, and this building near Llanelli.6
Coffee is served and seats taken and then we wait for three student nurses arriving from Swansea, who are coming for a leech training day and who are lost. Meanwhile: chat. Carl has worked at Biopharm for twenty-four years. He used to work with fish. “Just aquariums, like.” Then he was approached by the leech people on the basis that leeches need tanks too, and he has been at Biopharm ever since. His Welsh accent soothes as Welsh accents tend to do, even when he is talking about creatures that can make you bleed for ten hours and look like slugs and are slimy.
The leech is not a slug. Nor is it a bug, reptile, or insect. Sometimes it is not slimy either. The leech is an animal belonging to the phylum Annelida, a zoological category that includes over fifteen thousand species of segmented bristle worms and 650 species of leeches in the subclass Hirudinea.7 Not all leeches suck blood and not all bloodsucking leeches seek the blood of humans. Many have evolved to have impressively specialized food sources: one desert variety lives in camel’s noses; another feeds on bats. Some eat hamsters and frogs. The Giant Amazon leech, which can grow to 45 centimeters (17.7 inches) long, feeds by inserting a proboscis—like a long, 10-centimeter (4-inch) straw—into its prey.8
The leeches that I have driven several hundred miles to encounter are freshwater, bloodsucking, multisegmented annelid worms with ten stomachs, thirty-two brains, nine pairs of testicles, and several hundred teeth that leave a distinct bite mark.9 Depending on the era you live in, this resembles either a wound made by a circular saw or a Mercedes-Benz logo. Biopharm breeds both Hirudo verbana and Hirudo medicinalis. Until recently, verbana was thought to be the same species as medicinalis, and both were called the “European medicinal leech.” Now we know they are genetically distinct. The medicinalis are northern European by origin; the verbana are more Mediterranean.10 Biopharm also breeds Hirudinaria manillensis, named for its native habitat of Manila but also called the Asian medicinal leech or the buffalo, after its habit of dining on bovines. The European is bred to suck the blood of humans; the Asian is for veterinary use. The buffalo leech is fatter, hungrier, and less picky, used to piercing through hairy cattle legs or bellies. Europeans, more refined as bloodsuckers go, avoid stubble, perfume, hair products, and peculiar skin smells.
Both varieties have two characteristics in common: they inject their host with a local anesthetic so that they are rarely noticed until they have tucked in. Because of this, a leech bite will usually feel like a vague sensation, not a nip or scratch. Once their teeth are engaged, they emit the best anticoagulants known to exist, so that their blood meal keeps flowing long after they have stopped feeding, often for up to ten hours. The leech is in many ways a simple animal, but its anesthetic and anticoagulant have yet to be bettered by science. Roy Sawyer has often called the medicinal leech a “living pharmacy.” Only eight compounds in leech saliva have been identified, and there are probably hundreds that are useful. One, discovered by John Berry Haycraft in 1884, was later distilled into what became known as hirudin,11 vastly more efficient as an anticoagulant than man-made heparin, the next best blood thinner. Another is a “potent inhibitor of collagen mediated platelet adhesion and activation.”12 This was isolated after researchers noticed a strange thing: the leech bite made blood flow for hours, but not because of the hirudin. Instead, another substance—which Sawyer named “calin,” Welsh for “heart”—was stopping platelets doing what they were supposed to do, which is to aggregate and form a clot.13 On one patent database, there are ten entries for Biopharm covering antithrombins, hyaluronidase, inhibitors of fibrin cross-linking, protease inhibitors, and heparin-containing formulations.14 Not only is the leech a medicinal treasure chest, but its Mercedes-Benz bite is spectacularly efficient, the tripartite shape much less damaging than a scalpel incision, which can damage tissue. Apart from the bloodsucking issue, it seems to me that the leech is one of the more polite parasites. All in all, it is an astonishing creature, but I still don’t want to pick one up.
The student nurses have arrived with a whoosh of vigor and enthusiasm. They take a moment to enthuse over the musk turtle housed in a tank, a female named Jimmy that to me just looks lonely, then the leech jars and images. In my notebook, I write, “They are almost entirely undisgusted.” And later, “They are going to be really good nurses.” Then the introductory Biopharm video can begin. It starts with a twenty-year-old scene from the Elizabethan-era Blackadder: Edmund Blackadder is in love and wants a cure. He consults a doctor and the doctor prescribes leeches. The joke is that in Blackadder’s day the cure is almost always leeches. Doctors were called leeches, but because of an etymological coincidence, not for their fondness for prescribing worms. (Leeches were named for the Old English word laece, meaning “worm,” and derived from Middle Dutch; doctors were also called laece, but derived from the Old Frisian laki, meaning “a physician.”)15 This name for physicians lasted until the Renaissance and bequeathed to us such wonderful book titles as Leeching, Wortcunning, and Starcraft of Early England.
The leech is an ancient companion, and the idea of using it to treat maladies occurred to humans thousands of years ago. The body’s ailments were thought to be due to too much blood, among other things. Along with fleams and lances, the leech was an essential tool in the bloodletter’s armamentarium. Babylonians wrote of a striped bloodsucking worm that became “thick with blood” but also described the leech as a daughter of Gula, the goddess of healing. Dhanvantari, the Hindu god of healing, medicine, and Ayurveda, is usually pictured with a jar of leeches in one of his four arms. A wall painting in the tomb of the Egyptian scribe Userhat, thought to date to three thousand years ago, pictures a figure applying leeches.16 The first written record of leeching was probably in the Alexipharmica, a listing of poisons and their antidotes done in hexameter—as all medical literature should be written—by Nicander of Colophon, thought to have lived in the second or third century BCE, but there are leech references in Sanskrit, Persian, Chinese, and Arabic literature.17 The Chinese scholar Wang Chong, wrote Robert Kirk and Neil Pemberton in their fine book Leech, told of a king who accidentally swallowed a leech with his meal but said nothing, not wanting to embarrass his hosts. “Later, the king found himself cured of his chronic affliction. This was, Wang Chong explains, a happy effect of the leech having drawn blood from the site of illness within the king’s body.”18 (Actually a leech in the throat can swell and suffocate you.)
Bloodletting suited humoral medicine, the prevailing dogma for thousands of years. This held that the body was made up of four humors or liquids. The medical historian Hermann Glasscheib called them “the four juices.” A human was only a vessel for these life juices, which were yellow bile, black bile, white phlegm, and red blood. A cold, for example, was due to an excess of the white juice, which was then expelled through the nose and mouth. If someone turned yellowish, there was too much yellow juice. “The body had three doors through which it could evacuate nocive matter,” wrote Glasscheib. “Through the skin in the form of sweat, through the kidneys as urine and through the bowels as feces. But since there were four juices there must also be four exits. The doctors invented this fourth door in the shape of bloodletting.” Hippocrates, Galen, Paracelsus: all the medical celebrities believed in the power of relieving the body of blood. In the Canon of Medicine, the fourteenth-century Persian polymath Ibn Sina (Westernized as Avicenna) devoted considerable attention to bloodletting. It was “a general evacuation,” good for all sorts, medicine that was preventative and curative at the same time. It was useful when “the blood is so superabundant that a disease is about to develop [or when] disease is already present.”19 Different blood vessels served different purposes. Bleeding the veins between the eyebrows was good for long-standing headache, cutting the veins under the tongue—only lengthways, otherwise it was difficult to stanch—was useful for angina or tonsillar abscess. Opening the sciatic vein relieved podagra and elephantiasis; menstrual problems were alleviated by cutting the saphenous vein in the leg. The same vein was good for emptying blood from other organs. He did not recommend that blood be removed from humans aged less than fourteen or more than seventy. Young adults could increase their tolerance for adult-level exsanguination with “small blood-abstractions.”20 It’s easy to scorn this misplaced precision from our privileged position in the twenty-first century. My tonsils were removed as a child because it was standard procedure. I bled for hours into one side of the pillow and then, when the nurse turned it over phlegmatically, the other. Tonsillectomies are now considered old-fashioned and are rarely performed, only forty years later.
Bloodletting was as unquestioned as Band-Aids. Sometimes, it was a job requirement: monks had to be bled several times a year in bleeding houses called seyneys or flebotomaria, either as a sort of general body maintenance or for a more intriguing reason. Monks were supposed to be celibate, and chronic and enforced celibacy was thought to entail a dangerous buildup of semen (retentio semenis), which could lead to blood poisoning.21 Bloodletting avoided blood poisoning.22 Monks didn’t appear to mind and treated bloodletting as a holiday: they were relieved of choir duty and work, a fire was lit in the infirmary, and they got to eat meat.23
By Avicenna’s time, the job of bloodletting could be done by medical men but also by barbers. They were used to sharp instruments, and a papal decree forbidding monks from performing medical tasks meant monastery barbers began to diversify into doing small acts of surgery. This practice spread, so that barbers became instead barber-surgeons and formed a guild. The first barber-surgeon on the registry of the Worshipful Company of Barbers was recorded in 1312.24 The bleeding barber is the reason modern barbers display red and white striped poles: the pole was a stick for the patient to grip; the white stripes were the bandages, the red stripes the blood. The ball on the top was probably a deformation of the blood-gathering bowl.
Liber Albus: The White Book of the City of London, a 1419 rule book published by Lord Mayor Richard Whitington (better known as Dick, and for having a cat), provided instructions for all aspects of city life. As well as looking darkly upon foreigners, who could not be hostelers or sell meat, and forbidding the baking of bread made from bran, the rule book pronounced that no barber “shall be so bold or so daring, as to put blood in their windows openly or in view of folks; but let them have it carried privily unto the Thames, under pain of paying two shillings unto the use of the Sheriffs.”25 Barbers were bloodletters until surgery was established as a profession; there were tussles, and King George II finally put an end to the rivalry by setting up two separate guilds in 1745.26 After this, surgeons did surgery and barbers did what barbers do now, but both could pull teeth.
For two and a half thousand years, if you scratched at any account of illness, bloodletting would come out.
The video has moved on from Blackadder. We are approaching the nineteenth century, when leeching became leech mania. Leeching was accepted enough already that it was applied to royalty. When the Prince Regent of England fell ill in 1816, he was given thirty-six leeches in one go.27 In 1825, Emperor Alexander of Russia caught a fever in the Crimea. The empress urged him to submit to leeching, but he “rejected the proposition with great obstinacy and violence.”28 Only when he worsened did he accept leeches on his head. He died anyway.
It was another ruler who indirectly began the reign of the leechers. A surgeon in Napoleon’s army, François-Joseph-Victor Broussais, became “the most sanguinary physician in history.”29 The Napoleonic Wars, wrote Robert Kirk and Neil Pemberton, meant that “civilian surgeons had been absorbed into the military leaving few with the skills to perform bloodletting via the lancet. Broussais’s brilliance was to present an entirely new system of medicine that sounded modern yet was grounded in a simple, familiar and apparently safe therapy.”30 Broussais’s theory, based on his finding traces of blood in the digestive system on autopsies, was that all illnesses arose from inflammation of the guts. He called these inflammations “phlegmasies” and believed they could all be relieved by bleeding. So could head colds, syphilis, menstruation, flu, cholera, and gout. But he knew that bleeding was dangerous: people would often be bled until the point of “syncope,” or near death. All those opened veins got infected. Broussais thought the leech was a much better idea: even copious leeching did not kill as often as vein opening, and leeches were in abundance. Leeching was particularly useful for trauma, “when, for example, a wheel has passed over the body.”31 Inflammation could also be reduced by applying leeches to the anus. “You will in an instant remove a phlegmasie from six inches to a foot wide.”32 (He does not describe this in any more detail, leaving me to wonder what a foot-wide inflammation out of the anus looks like. Briefly.) A toddler needed only one or three leeches, and a woman, fifteen. A grown man should be given sixty in one application. Broussais was a star; his lectures were so notorious, the minister of war (or police, depending which source you believe) once had to close the lecture-hall doors to keep out besieging hordes, and his theories were revered. At the beginning of the nineteenth century, France produced enough native leeches to export them. By 1833, it had to import 41.6 million leeches.33 French doctors by now ordered their patients to be leeched even before they met them, no matter what the trouble. A worm prophylactic.
Where were all these leeches coming from? When they were abundant in European marshes and ponds, leech gatherers would walk bare-legged through ponds to harvest them. The Wellcome Collection in London has a bucolic engraving of Yorkshire women gathering leeches to put them in small barrels, and Wordsworth wrote a poem about a Lakeland leech gatherer, who “roamed from Pond to Pond and moor to moor / Housing, with God’s good help, by choice or chance / And in this way he gained an honest maintenance.”34 It was an honest occupation but not poetic or bucolic. In France, it was known as “blood fishing.”
You would suddenly see a young woman soften and sway, as if she was drunk or dizzy, sometimes slump into the pond, her legs in the mud but her head in the clouds. Her companions knew what this flagging meant: a weakness caused by the insatiable vampirism of leeches. So they would quickly get the stunned girl out of the mud to free her from the slimy parasites.35
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 hungrier 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
Unless you know better. Unless you are a plastic surgeon. When the surgeon Iain Whitaker did a telephone survey of all the sixty-two plastic surgery units across the UK in 2002, 80 percent of the fifty that replied had used leeches postoperatively in the salvage of compromised free flaps or digital replants within the last five years. Three units had used leeches more than sixteen times a year; fifteen had used them up to five times.57 There are abundant leech papers in journals of plastic surgery, maxillofacial surgery, and microsurgery detailing proper leech procedure. Leeches are judged to be effective in the salvage of various essential body parts such as fingers, ears, nipples, nasal tips, and penises. (Leeches were not used in the famous penis reconstruction of John Wayne Bobbitt but were apparently on standby.)58
By now, leeching is most commonly used in flap surgery, the transfer of a living piece of tissue from one part of the body to help another part, used in breast reconstruction, open fractures, large wounds, and improving cleft palates. Unlike a graft, the flap comes with its blood vessels attached, and the incoming blood vessels must be attached to the existing ones, an intricate and infernal weaving. Attaching tiny blood vessels calls for a microsurgeon, and if the blood vessels get congested, the microsurgeon calls for a leech. It is unquestioned practice now. Biopharm sends out leeches every day. Today’s packages are going to Cyprus and Finland.
Things have changed since Upton’s fly-by-night leech delivery. Both Hirudo medicinalis and Hirudo verbana are now endangered species, listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.59 To export a leech you need a permit from CITES, and a permit can take six weeks to organize. This seems odd, in a building where leeches are breeding like, well, leeches. “Ours aren’t endangered at all,” says Carl. “We’ve got plenty.”
“We had an instance,” says Bethany, “where a Saudi doctor rang and said, look, this five-year-old boy is going to lose his foot, we really, really need them. It was frantic, it was just constant work between us speaking to the CITES authorities, and speaking to the airline trying to get all the air freight organized. We are two and something hours away from Heathrow. Our courier has gone away with everything and we had to speak to customs and say, can we get it done today rather than in two or three weeks. They actually held the Saudi Airlines flight for two hours for our courier to get up there.” As further proof that the boy was probably the well-connected kind of Saudi, the leeches were carried by the wife of one of the owners of Saudi Airlines.
CITES is a frustration. “I’m just waiting for somebody from CITES to cut his arm off,” says Carl, “and they say, you have to wait for the permit.” Airlines are another trouble. There aren’t many medical devices that are alive, so while leeches are medical devices, airlines treat them as livestock, and they don’t like carrying livestock. Some airlines are better than others at keeping their hold temperatures cool in the summer. Boiled leeches are always a possibility.
* * *
It’s time for the handling. Carl doesn’t have any appropriate Europeans, so we are invited to pick up a buffalo. He fetches a leech that looks big and black and, though I know better, a lot like a slug. He says, “This species is slimy. It’s super, super slimy.” Is that relish in his voice? He invites the first junior nurse to put her hands out. He will put his hands underneath in case the shock makes her drop it, but she is not shocked. She is entirely sanguine, in the English sense (the French have decided it means fiery and excitable). This is a nurse who won’t balk at bedpans. Carl gives an audio tour of the leech while it moves on her hands, sniffing and looking for a bite. “This is the biting end. That’s the holding end. The reproductive organs are there.” He tells us the color means that the leech is pregnant, and the nurse nearly drops it. “Don’t worry. They’re as tough as old boots.”
Will it splat?
“No. And they take quite a long time to bite.” An attached leech can bite in six seconds; a handled leech is slower. “You’d be surprised how much time you’ve got.” He estimates twelve to fifteen seconds, although he no longer needs to count. “I can see where the muscles are, when it’s about to bite. I can see exactly.” He also knows which leech it is, and who its parents were: this one has two stripes, and his and her parents had one each. I ask him if he gives leeches names and his expression says that is a very stupid question. “No. But they definitely have traits. Some are more aggressive than others, some are faster than others. Some are really placid.”
The second nurse takes the leech. She squeals. “Don’t worry,” says Carl. “The head is nowhere near. Chill out!” I ask her what it feels like and she says, “Like there’s a leech on my hand.” One more nurse, one more period of fewer than fifteen seconds of leech holding, and then it’s my turn.
I have blanked out what it felt like. My recording tells me that I said, “It’s all right, actually.” Then, immediately, “You can have it back now.” A picture shows my face screwed up in a classic expression of disgust. I remember something that felt not like slime but like nothing else. Cool. Alive. Something I didn’t want on my hands. I have no idea how I’d tolerate them on a ravaged ear, a reconstructed breast, a torn-off finger. I have no idea how I could be persuaded.
* * *
After months of reading papers on leeches, I notice something. Leech therapy “was well received by virtually all,” wrote Whitaker in his survey of plastic surgery units, “with only a small number of units reporting patient noncompliance within the last five years.”60 In a journal of head and neck surgery: “No patients had leech therapy stopped because of inability to tolerate the treatment.”61 A patient information leaflet on leech therapy: “The nurse will explain leech therapy to you and make sure you understand the process before applying the first leech.”62 By all these accounts, persuading a patient to undergo leeching is no more problematic than offering a needle. But the leech is not a needle, despite Carl’s analogy. It is a bloodsucking parasitic creature that has suckers and teeth. It is disgusting. Or is it?
There are good reasons that humans find things disgusting. For disgust theorists—there are such people, and they are great—it’s because things and creatures that disgust are things and creatures that are dangerous. A discarded hair that can transmit disease is more disgusting than one attached to a head. A caterpillar, which is unlikely to infest you, is less repellent than a worm, which might. This biological determinism is not fixed: what is found disgusting varies according to age, geography, and status. The disgustologist Dr. Val Curtis found that Indians were disgusted by urine, sweat, menstrual blood, cut hair, childbirth, vomit, mice and rats, lower castes, and decaying waste.63 The Dutch, meanwhile, were repelled by shit, stickiness, and fishmongers’ hands, as well as cats and dogs. When the author William Miller explored the disgust of Americans, he found them to be repelled by “feces, bodily fluids, pustules, rotting wastes, severed limbs, pubic hair, sexual fluids, graveyards, slaughter houses, compost, carrion, slugs, maggots, bloodsucking parasites and deformity.”64
Disgust is why the leech has been perverted into a symbol for malignity, parasitism, evil, and corruption, so that its secondary dictionary definition after “parasitic or predatory annelid worm” is “a person who extorts profit from or lives off others.” It is why Adolf Hitler and Nazi propaganda equated Jews with leeches, with pronouncements such as the Jew “whines for the favor of ‘His Majesty’ and misuses it like a leech fastened upon the nations.”65 It is why Dr. Peter Mark Roget, in his thesaurus, gave the leech five entries, and one is bane, subcategory “troublemaker,” along with parasite, threadworm, tapeworm. I love Roget’s thesaurus, but this seems unfair. I accept that the medicinal leech is not benign, however useful: as it lacks enzymes to digest blood by itself, it relies on bacteria in its gut to do the work of digestion. Patients’ wounds have subsequently been infected by Aeromonas hydrophila, other members of the Aeromonas genus, and Vibrio fluvialis, so antibiotics are given prophylactically as routine. But the leech will not infest your guts like a tapeworm nor trouble you like a threadworm. A single leech will not kill you, though several hundred may. I’m not sure, given all the use and abuse that humans have made of leeches, who is the parasite and who the prey.
It’s true that leeching presents risk. Getting the leech to bite where it is wanted is not straightforward, and the literature is full of helpful suggestions of how to coax it into the needed position. A group of Mumbai doctors wrote to the Journal of Plastic, Reconstructive & Aesthetic Surgery in 2009 recommending applying the leech enclosed in a syringe tube, a method with “an obvious aesthetic advantage.”66 Cutting a square in the center of a piece of gauze and guiding the leech to it is another option. My favorite suggestion appears in an article in the Lancet of 1849 titled “Leeches Drunk Will Bite Till Sober.” Instructions: “Put the leeches that you are going to use in some warm porter, and directly they kick about in it, take them out, hold them in a cloth, and they will bite instantly, without fail, even if they have been before tried for some time without any success.”67
Leeches move more than other medical devices. In the literature, this is known as leech migration and it causes countless problems, because they can migrate both inside and outside the body. Some leeches have migrated to a patient’s throat; others to the bronchus, air passages leading to the lungs. In the past, leechers attempted to train their leeches by sewing a string to them. In a treatise on the leech, the nineteenth-century physician James Rawlins Johnson thought leeching useful for “phrenitis,” an ailment believed to derive from a retention of the menses, and, according to Zacutus Lusitanus, a sixteenth-century Portuguese physician, best treated by fastening four leeches to a piece of thread and introducing them as closely as possible to the uterus. “Lusitanus is so warm an advocate for their employment, that he declares there is no disease but will become mild under this mode of treatment, and particularly should the leeches be applied to the vessels of the anus.”68 There have been as many proposals to counter leech migration as there have been papers on repairing free flaps. But the best way to get a leech to bite accurately and to stay put is to have it watched. The people who must do the watching are nurses.
For months, I can’t find nurses in the leeching literature. They must be there, but their voices are silent. It is a puzzle. Without nurses, who would apply the leech and soothe the patient, and watch for leech migration and kill the helpful creatures when they are finished? And how do nurses overcome the disgust mechanism they must surely feel, because they are human, without conveying it to the patient? Then, late one night, I find a paper from the British Journal of Nursing, “Nurses’ Experience of Leech Therapy in Plastic and Reconstructive Surgery.” The authors are Alison Reynolds and Colm OBoyle.69 The study area was a thirty-bed plastic surgical ward in a major Dublin teaching hospital staffed by twenty-six nurses, five consultant plastic surgeons, and eight hospital doctors. The ward uses leeches about once every three months.
Reynolds was no leech specialist at first. She had encountered them as a student nurse, rotating around hospital departments and working on the plastic surgery ward. Then, in the early 2000s, leeching was more common because of the times. Ireland was rich. Eastern Europeans—mostly Poles—came to work in factories but without enough English to understand instructions. Poor comprehension met heavy machinery and traumatic injuries abounded. I ask Reynolds to recount her first leeching, but it was too long ago and there have been too many instances since then. She thinks she was on nights and was told, “You have someone here who’s for leeching,” and her reaction was what my reaction would be: “How am I meant to do that?” There was no official policy to give guidance. Nothing was written down. You asked your colleagues, and you took the things that looked like slugs, and you did your best.
The paper came about because she needed to write a thesis for a master’s degree. She discussed her work in plastic surgery nursing with OBoyle, a midwife who was her thesis supervisor, and when she got to the fact that in plastic surgery they used leeches, he said, “Stop!” It had to be leeches. But then she did what students are meant to do and looked at the literature. “And there was literally nothing.” Irish emphasis. Literally. Nothing. One paper written by a nurse in the late ’90s. Plenty of papers by surgeons about flaps and veins. But nothing from nurses about what having someone for leeching meant, nor how they felt about it when they set off for the patient’s room clutching a tub of annelids. She panicked and went to OBoyle. “I’ve got no foundation!” But he said, “Your foundation is that there’s nothing out there.”
She interviewed seven plastic surgery nurses. Every one disliked using leeches. “They might visibly squirm and distort their faces as they described the leeches and their need to be close to and manipulate them.” They described them as “the black slug,” “bloodsucking, slimy bugs,” and “creepy crawlies.” Other things they didn’t like: that the leech, that “dirty walking needle,” went against all their training: hygiene control was paramount, yet a live creature full of potentially toxic blood was moving around their hygienic hospital ward. Reynolds uses the anthropologist Mary Douglas’s famous definition of dirt as matter out of place. “The recasting of such matter (parasite) that is conceptually out of place […] would appear to be a challenge.” Having someone for leeching means extra care but no extra staff, or money. Plastic surgery nursing does not count as specialized, unlike oncology or midwifery. This is ludicrous, and Reynolds is indignant at it. Leeching is specialized. Not everyone can do it. It’s hard.
Migration, for example. I tell Reynolds that most surgeons gloss over this. If she were less polite, she’d snort, but her derision comes through anyway. “That’s typical surgeons. Migration is a big problem and anyone who says it isn’t clearly isn’t doing the therapy themselves.” Leeches move. They always move. “They’d be anywhere. Anywhere. Especially when you’re on nights, the lights are down, we’ve got a little nightlight, but you’re walking in watching your step because you could walk on one.” She has found leeches up curtains, on the radiator, on the floor, in the bathroom, in the shower. “You try to go in every fifteen minutes or half an hour but if it’s fallen off, it can fall anywhere, and then they just slide around, so you have trails of blood.”
It sounds so gothic and shocking. Why do patients agree to it? Because they have to. Only patients whose transplantation has failed are offered leech therapy, and the leech is the last resort. “It’s not like ‘I don’t need those tablets, I don’t need them’ and there are no repercussions.” Your repercussions are a lost finger or ear, or one reconstructed breast and one void. “You thought you were going to come in, you were going to have the surgery and you were going to go home and be yourself again, that this was going to be your identity.” No one offered leech therapy, says Reynolds, has ever refused. I press her. Even so, how do you persuade someone to submit to it? She says the surgeons come around first and suggest it. All official, like, with their white coats and terminology. “But I know that [the patient] is sitting there and I know they’re thinking, I’m going to ask the nurse later about this. The consultant will go through the medical stuff. But the itty-bitty things? They’ll ask the nurses.” She’s always right. The consultant leaves, and the patient says, “I didn’t really know what he meant, does he mean the little slug thing?” Reynolds always answered truthfully. “But I would always give my encouragement because I’ve seen this work. It might not, but at least we can say we’ve done everything.”
There are differing levels of acceptance. She delights me with a tale of a farmer. “He loved it. He thought this was amazing. He said, ‘Put them on, I’ll watch them, don’t worry, when that fella’s finished, I’ll ring the bell.’ He was watching them thinking it was the most fascinating thing ever. He’d say, that one did well now didn’t it?” His treatment was successful and he phoned all his friends to tell them about it. “But he was a farmer. A different kind of outlook.”
The Biopharm video includes a news report about a woman named Michelle Fuller, from Bradford. She was young, she had children, and she had mouth cancer. Later, running across Yorkshire moorland with a new acquaintance, I’m surprised at her lack of surprise when I say that I’m writing about leeches. It’s because Michelle was her cousin. She tells me Michelle tried the leeches because she was sure they would save her life. No doubt about it. The leeches were placed on her new tongue, which had been constructed from a flap, four times a day for ten days. “I have never been squeamish,” Michelle told the local paper. “And I just said you have to do what you have to do.”70 The Daily Mail wrote that “bloodsucking leeches saved a woman from cancer,” but they didn’t.71 She died eight months later, aged thirty-three, a few weeks before her planned wedding, and I salute her.72
The farmer and Michelle and other broad-minded patients: they’re the easy ones. “Some people,” says Reynolds, “just don’t want to know. ‘Don’t tell me, I’m not going to look, come in, come out, do what you need to do, but I’m not an active participant.’” The face and breasts are the hardest. Women undergoing breast construction are “already emotionally distressed and they find it harder.” Delayed reconstruction therapy, for example: these women have had chemotherapy and radiotherapy, and only then a reconstruction. Already they have waited months, and they have the surgery and then one breast fails. “That’s so huge for a woman. It’s part of your identity, it’s who you are, and it’s not going well and then you have leeches stuck on your boobs as well.”
Some of the nurses Reynolds interviewed can’t bear leeches, either, but because they are nurses, and wonderful, they suck it up. In one newspaper article titled “A Sucker’s Born Every Minute,” an unnamed doctor at Cedars Medical Centre reported an interesting technique for getting nurses used to the idea. “‘We first ask them if they like animals,” the physician says. “Then we work up to leeches.”73 Or the more junior nurses do trade-offs with more veteran ones who don’t mind the creatures. Reynolds knows better but, despite her knowledge and expertise, thinks leeches are “slugs. One hundred percent slugs.”
They are also trickier to dispose of than a sharp needle into a bin. From Biopharm, I’d got the sense of a dispatch method that was clean and humane, if animal murder can be humane. No, says Reynolds. It’s nothing like that. Wild Hirudo medicinalis or verbana may live for twenty-seven years,74 but these are service animals with a human-dictated life span. Its job done, the useful leech is placed in a plastic pot—like the urine sample ones—and sprayed with alcohol solution. Rather than it being anesthetized and dying painlessly as I’d imagined, there is an explosion. “They’re so big,” says Reynolds. “And you spray them with seventy percent alcohol, and they burst open with all the blood.”
* * *
You will not find many vivid news reports about patients who have successfully undergone surgery and overcome venous congestion of a free flap. They are quiet, the successfully leeched, and there is no public triumph. Perhaps they need to forget. Perhaps they can’t square the instinctive horror of the leech with its powerful ability to heal. Perhaps they cannot summon gratitude for these slug-like creatures. They should.
In the nineteenth century, a man named Thomas Erskine was convinced that being bled by two leeches had saved his life. Despite the abundant use of leeches, gratitude to them was rarely expressed. But Erskine—who served as Lord Chancellor in the most optimistic Ministry of All the Talents—named his leeches Home and Cline, after two eminent Victorian surgeons, and made them pets.75 Another man who gave leeches their due was George Merryweather, a family doctor in the Yorkshire port of Whitby, famous for being a setting in Dracula but also where Dr. Merryweather devised the Tempest Prognosticator. In a long submission to the Whitby Literary and Philosophical Society in 1851, Merryweather set out his startling claim: that a leech could feel weather, and that many leeches could predict it.76 This barometer ability of the leech had been reported anecdotally before. The eighteenth-century poet William Cowper wrote to his cousin of a storm and of “a leech in a bottle that foretells all these prodigies and convulsions of nature. […] No change of weather surprises him, and that in point of the earliest and most accurate intelligence, he is worth all the barometers in the world.”
Merryweather read of this and went further. Rather than one leech, his barometer featured twelve, each in a white glass bottle, pint-size. He took care that they could see one another, because he thought leeches could get lonely. He called them his “jury of philosophical counsellors” and “my little comrades.” In his writing, a kindness percolates. He is apologetic in his submission that he must predict yet another storm, though the sky is blue. “I am sorry to interfere with your engagements this beautiful weather,” he writes in February 1850. “I do not trouble you with a little blustering of the wind.” But he is rare in that his kindness extends to leeches, these animals thought to be only useful or to be abused.
He thought of calling his device the Atmospheric, Electro-Magnetic Telegraph, conducted by Animal Instinct, but somehow decided that Tempest Prognosticator was more straightforward for foreigners to understand. He suggested that it be placed in stations around the coast to serve all shipping, along with life boats, and that mariners be issued a book of tempest signals, to interpret better. The prognosticator appeared at the Great Exhibition of 1851, and Lloyds of London did its own tests.77 But the leech machine failed: the mechanical barometer, using a sealed liquid, was adopted instead, partly because it didn’t require maintenance, feeding, or the changing of water every few months. Merryweather’s comrades were retired, and the leech returned to its role as an unloved worm.
* * *
Leeches are called upon less often now, because surgery is better. “We’re a bit flat really,” says Carl, when I ask how business is. The young nurses at Biopharm thought their hospital used to keep them on the burn unit, but they don’t anymore. Surgeons are defter at reattaching veins and getting drainage, but only with clean cuts and decent-size veins. “Where there is trauma,” says Carl, “someone is burnt or something gets caught in a chain or a belt: that’s when they can’t stretch the veins to get them together. So they attach as many arteries and veins as they can and use leeches to borrow a bit of time.” In America, Biopharm’s leeches are used frequently for scalp injuries. “Bears,” says Carl. “They tear the scalp off. It’s one of the few things when there’s very little that they can do surgically. They attach the scalp and then plaster it with leeches. It works very well.” Canning factories used to be good for business. Carl remembers one case where a canning employee in Finland had two fingers and a thumb ripped off. “I think they used something like eight hundred leeches over five days. I don’t know how they used so many.” Degloving cases, where the skin is ripped off, have also dropped.
But in disasters overwhelmed surgeons can’t afford to spend ten or twenty-five hours of surgery on each patient, and leeches can save time. After the San Francisco earthquake in 1985, Roy Sawyer wrote in a biographical account that Biopharm had requests for hundreds of leeches. The same after the terrorist attacks of 7/7 in London.78 Wars often require leeches: according to Carl, the Royal Centre for Defence Medicine in Birmingham keeps two hundred leeches in its pharmacy. “They have a really big stock,” says Carl, because they have people coming in with no leg, no foot. It’s not a case of putting one or two on, they’ve got to put fifty on.” Regular hospitals used to keep a leech buffer—half a dozen or so, in the pharmacy—but most don’t now.
July has been quieter than expected. In summer, people do DIY, and, Carl says with meaning, “They cut the hedge…” I ask if they attend surgery conferences to increase trade. “When we can afford it.” It’s a rare chance for them to meet surgeons and doctors: usually they only deal with the pharmacist, who orders the leeches in and sometimes not expertly. “We’ll get a pharmacist ringing in at six in the morning and saying, can I have six leeches, and we’ll say, no you don’t want six because by the time the courier gets to you, you’ll be needing more.”
Surely there’s an untapped leeching population in the rugby and boxing worlds where cauliflower ears and contusions abound? For now they just get the odd human kickboxer from a local club. They are walk-ins, popping in for leeches when required, no need to book. Carl can’t remember what the boxers were charged, but the usual price is £9.50 to £10 ($13.35 to $14.07) a leech. Whichever way you look at it—compare it to the painstaking two-year breeding process, or calculate it against three or more visits to a casualty department for a cauliflower ear, or a lost finger or breast or scalp—that is a bargain.
What about diversifying into hirudotherapy? The general public already thinks leeching is quackery, say Bethany and Carl. Or that it’s something to do with maggots. But when I bring up hirudotherapy, their reaction is dour and sour and no wonder. The website of the British Association of Hirudotherapy is accompanied by images of women with leeches hanging out of their mouths or in their genitalia. In the curious minds of hirudotherapists, leeches applied correctly will treat diseases caused by “insufficient micro-circulation.” These include blood defects, joint disorders, neuroses, boils, hemorrhoids, varicose veins, asthma, heart attack, stroke, depression, infertility, memory disorders, diabetes, hair loss, and detached retinas. The actress Demi Moore told talk show hosts that leeches had fed on her to “detoxify my blood,” saying they released a cleansing enzyme. This is scientific nonsense: if the leech’s decongestant ability was not localized, its host would bleed to death. The only thing hirudotherapy claims it can’t treat, says Carl, is death. But science is immaterial to hirudotherapists, as are laws. I ask Carl where hirudotherapists get their leeches from if it’s not Biopharm. He says nothing for a while, then relents. “A pond somewhere. A lot of them come from Russia without CITES. All the leeches that come in are smuggled, in a suitcase. They get their relatives to bring them in.” It’s easy to check: CITES regulates imports and exports. In 2017, Romania was allowed to export forty thousand Hirudo medicinalis; Turkey was allowed a quota of 200 kilograms of Hirudo verbana. Russia had no leech quota for 2016–17.79 Carl says Russia exports two hundred leeches every few years. “But the hirudotherapists are using five hundred a week.”
Perhaps a few things on that long hirudotherapy shopping list of conditions are not entirely lunatic. Carl has heard that they’re good for tendonitis. Their saliva has some kind of anti-inflammatory effect. “But there’s no exact science as to why it works.” In 2003, the surgeon Richard Fiddian-Green wrote a letter to the British Medical Journal. He remembered doing a ward round at St. Mary’s Hospital in London with a senior consultant and encountering a patient with extremely painful pericarditis (a swelling of the fluid-filled sac enclosing the heart). It is usually treated with anti-inflammatory drugs. But the consultant thought differently. “The most effective treatment for pericarditis I have ever seen,” he told us, “was three leeches applied to the precordium.”80
Anecdotes abound of leech application helping to relieve arthritis or other inflammation. I’d like to ask Roy Sawyer about it, but Bethany says he doesn’t do interviews anymore. She nods in the direction of the cream mansion house, where he is. I start to think of Jane Eyre and attics but I tell them that I picture him as an Indiana Jones figure, striding through swamps for science, his movement purposeful and his legs bare and ready. They don’t stop laughing for a good while. “Not quite,” says Bethany. Her parents are planning a holiday, she says. “My mother thinks it’s going to be a relaxing holiday, but he’s already got plans to find a swamp somewhere.” Neither she nor Carl looks like they relish this idea. When Sawyer is out leech hunting, he sends them regular e-mails of his progress. Images of dissected leech gonads in their morning in-boxes are not uncommon.
Sawyer is going swamping because he may be retired from giving interviews but not from learning about leeches. There is so much to discover about these multisegmented annelid worms, this bane and troublemaker and parasite, this bloodsucking creature that straddles old and new medicine as serenely as it moves through water or attaches itself to Carl’s trouser leg. It has given us much, this wee black slug, but Roy Sawyer is convinced it has more. “Secretions from bloodsucking animals,” he told a reporter, “could be to cardiovascular diseases what penicillin was to infectious disease in the past.” He listed the possibilities, and his belief was as high as the rain forest. “Blood clotting, digestion, connective tissue, disease, pain, inhibition of enzymes, anti-inflammation. You name it, the leech has it.”81