One French Farm Supplies Most of the World's Hospital-Grade Leeches

A single company outside Bordeaux breeds the animal the FDA classifies as a Class-I medical device, and its bacteria have already crossed the Atlantic once.

By Carry and Conquer Publications

Twice a year, technicians at a low warehouse in Eysines, a suburb of Bordeaux, wade into shallow basins to net thousands of small, banded worms that have been fasting for months. The animals get sorted, washed, counted, and packed into breathable containers bound for hospital pharmacies on five continents. Nothing about the scene looks like a medical device factory. But under the Food and Drug Administration's own classification, that is precisely what Ricarimpex SAS produces: a living, prescription-only Class-I device, cleared in 2004 to treat human patients, made not in a cleanroom but in a pond. The company estimates it ships roughly 80,000 of the animals into the United States every year. Almost every hospital in America that keeps a tank of medicinal leeches on hand for reconstructive surgery is, whether it knows it or not, relying on the health of that one French farm.

The First Animal the FDA Ever Cleared as a Device

Medicinal leeches, Hirudo medicinalis, occupy a strange legal category. Before 1976, any American company could breed and sell them freely. The Medical Device Amendments of that year changed the rules for anyone entering the market afterward, and for nearly three decades no company bothered to seek clearance, since existing suppliers were grandfathered in. Ricarimpex broke that pattern. On June 21, 2004, the FDA's 510(k) division cleared the firm's premarket notification, K040187, making Ricarimpex the first company in American regulatory history to receive clearance to market a living animal as a medical device. The agency's review process looked nothing like a typical device audit: instead of bench testing and sterility validation, FDA staff evaluated published medical literature on leech therapy, safety data Ricarimpex supplied about its breeding operation, and an inspection of how the animals were fed, housed, and handled by staff. The product code assigned, NRN, still governs the leech's regulatory status today, and the clearance itself has been administratively updated as recently as June 2025, still addressed to Ricarimpex's president at the same Avenue de Saint Medard address in Eysines.

What earned that clearance is a specific piece of microsurgery. Reconnecting a severed finger, ear, or flap of skin is largely an exercise in plumbing. Surgeons can usually reattach the thicker, muscular arteries that pump blood into damaged tissue. The thin-walled veins that are supposed to carry blood back out are far harder to rejoin, and when they fail, blood pools under the graft, the tissue swells and darkens, and without intervention it dies within days. A leech solves the problem the way nothing else quite does: it attaches, draws out the pooled blood over roughly fifteen minutes, and injects a cocktail of anticoagulant and vasodilator compounds, chiefly hirudin, that keeps the wound bleeding for four to six hours after the animal has dropped off, sated. That window buys surgeons the days they need for tiny veins to regrow on their own. According to French hospital survey data published in 2018, roughly 70 percent of France's university hospitals use leech therapy, and clinical reviews in plastic surgery journals report flap salvage rates as high as 88 percent when the therapy is administered without complication.

A Three-Time Olympic Medalist Bought a Leech Farm

Ricarimpex's president, Brigitte Latrille, did not arrive at hirudiniculture by any obvious path. Under her maiden name, Brigitte Gaudin, she won three Olympic medals in team foil fencing across the 1976, 1980, and 1984 Games and took the world junior title in 1978. She spent more than fifteen years afterward working as a flight attendant. In 1993, she bought Ricarimpex, a company whose roots in the leech trade trace back to 1845, and by most accounts she has run it with the same intensity she once brought to competitive fencing: associates have said she went more than twenty years without taking a vacation. Under her leadership the company built out a laboratory-controlled breeding operation at its Eysines headquarters alongside roughly six thousand square meters of river-fed natural basins at a second site near Arcachon, and became, by its own account, the only company in France still producing and selling medicinal leeches at all. It is one of just three producers left in Europe.

The animals themselves are farmed, not merely collected. Because feeding wild-caught leeches on live animals is no longer standard practice, and because cattle blood raised fears after the era of bovine spongiform encephalopathy, Ricarimpex has fed its stock poultry blood since 2001. A leech that has fed is retired from clinical use; the ones Ricarimpex ships have typically fasted six months, so that when they finally reach a hospital pharmacy and are applied to a graft, hunger does the work. In a market this narrow, Ricarimpex has effectively no French competition and only one meaningful rival worldwide: Biopharm Leeches Ltd, based in Swansea, Wales, which supplies a little under 20,000 leeches a year to the American market against Ricarimpex's roughly 80,000. Between two small companies on opposite sides of the English Channel sits nearly the entire global supply of a device that American microsurgeons consider irreplaceable for certain reattachments.

Bacteria That Crossed the Atlantic Inside the Device

In December 2012, surgeons at University of Iowa Hospitals and Clinics used leeches from a hospital tank to save a facial skin graft on a patient recovering from tumor removal surgery. They had, as protocol required, already put the patient on ciprofloxacin to guard against Aeromonas, the bacteria that lives symbiotically in every leech's gut and helps it digest blood. The infection came anyway. Lab tests confirmed the Aeromonas in the wound was resistant to the very antibiotic meant to stop it. A search of hospital records turned up a nearly identical case from five months earlier, and further digging turned up reports of the same resistant pattern surfacing in Missouri, California, and France.

Solving the mystery took five years and a research collaboration between Dr. Bradley Ford, director of microbiology at University of Iowa Hospitals and Clinics, and Joerg Graf, a microbiologist at the University of Connecticut who had spent years studying the specific bacterial ecosystem inside a leech's digestive tract. Graf's graduate student, Lidia Beka, built what amounted to a bacterial family tree, sequencing Aeromonas strains pulled from surgical wounds in Iowa, Missouri, and California alongside strains extracted directly from new leech shipments, including one sent by Ricarimpex and forwarded, unopened, by its American distributor, Leeches U.S.A. The genomic match was unmistakable: bacteria swabbed from an operating room in Los Angeles sat almost identical, on the family tree, to bacteria pulled straight from a French-bred leech's gut.

Tracing the Resistance Back to a Feeding Decision

The team's published findings, which appeared in the journal mBio in 2018, found that in leech shipments from 2013 and 2014, roughly 95 percent of Aeromonas strains carried a genetic marker for antibiotic resistance, compared with under 1 percent in shipments from 2009 and 2011. Chemical testing on the more recent leeches turned up trace residues of ciprofloxacin and of enrofloxacin, a veterinary antibiotic that breaks down into ciprofloxacin inside an animal's body, and that happens to be approved for use in poultry. Beka ran head-to-head competitions between resistant and susceptible bacterial strains inside live leeches and confirmed that even the faint drug concentrations found in the animals' gut juices were enough to let resistant Aeromonas outcompete its susceptible counterparts.

Latrille, in comments to the science news outlet STAT, said no regulator had ever raised the issue of the company's feed source with her, and confirmed that Ricarimpex's leeches have eaten chicken blood, not the historical alternative of cow or horse blood, since 2001. She noted the company had not identified problems with its leeches during the study period, but that in 2015 it began layering in additional controls, and by 2017 was testing every lot for drug-resistant bacteria before shipment. The problem has not gone away. FDA adverse-event records show that in 2023, a patient who underwent a finger-replantation procedure developed a multidrug-resistant Aeromonas caviae infection after treatment with leeches from a Ricarimpex lot, ultimately losing the reattached digit to amputation despite antibiotic treatment. Manufacturing records for that lot showed no defect on Ricarimpex's end; the leeches simply carried, as leeches always do, bacteria that modern antibiotics no longer reliably control.

A Chokepoint Built on a Pond

What the Iowa investigation exposed was not a single bad shipment but the structural fragility sitting underneath a genuine, evidence-backed piece of modern surgery. A supply chain concentrated in two small firms means that whatever happens inside Ricarimpex's basins outside Bordeaux, or whatever antibiotic residue washes through a poultry farm feeding its stock, has a direct and fairly short path into an American operating room. The company has responded with the tools available to a compliance-conscious device manufacturer: lot testing, updated husbandry protocols, a user manual that flags which antibiotics are unsafe to pair with its animals. Hospitals, in turn, have shifted away from ciprofloxacin toward other prophylactic regimens as resistance patterns evolve, the same adaptive game played across every other corner of antimicrobial medicine.

None of that changes the underlying arithmetic. There is no third major supplier waiting to absorb demand if Ricarimpex's basins were ever compromised by disease, contamination, or a regulatory suspension, and wild leech populations are far too depleted, and in many countries legally protected, to serve as a backstop. A woman who once fenced for Olympic medals now controls, through a family-owned company on the outskirts of Bordeaux, a meaningful share of the world's capacity to save a reattached finger or a failing skin graft. The 2018 outbreak was traced, treated, and largely forgotten outside specialist circles. But it left a clear marker of what concentration in even the strangest corners of the medical supply chain can mean: when the chokepoint is a living animal, the risk does not stay contained to a warehouse in Eysines. It travels in the bloodstream of the patient on the other end.