Antibiotic-resistant infections appeared after surgery. Were they transmitted by leeches?
Originally published on STAT News
The enigma emerged in the form of some greenish-white pus, swabbed from the wound of a patient not long after surgery. On Dec. 13th, 2012, surgeons at the University of Iowa Hospitals and Clinics had excised a tumor from his face, patching over the wound with a Post-it note of flesh from his thigh. But that flap had died, and a week later he was under the knife again, to have his wound re-mended with a strip of skin from his back.
When doctors saw blood pooling in the new graft, threatening to kill this one, too, they had the perfect treatment. Down in a hospital lab was a tank rippling with leeches. They fished some out and placed them on the man’s face.
Things got better for Christmas. For New Year’s, they got worse. The wound had started oozing pus, which smelled like a sewer and baffled the physicians. Leech guts, like ours, are crawling with bacteria, so the team had pumped the patient full of ciprofloxacin before allowing his blood to be sucked. That should have stopped any infections before they started. Then lab tests confirmed their suspicions: These bugs, called Aeromonas, were cipro-resistant.
When they searched the hospital’s records, they found another, similar case of antibiotic resistance, from July 2012, when plastic surgeons had used leeches after repairing a foot that had been crushed by a crane. There were reports from hospitals elsewhere, too: California, Missouri, even France.
Where was the resistance coming from? Five years later, a team of leech obsessives and bacteria growers have found an answer, published Tuesday in the journal mBio. Their work points to the butterfly effect of globalized medicine, with ideas and diseases ricocheting wildly through space and time, appearing, disappearing, reappearing. Just as a seemingly defunct treatment can rise from the dead, so the ghostly trace of an animal drug might resurface in humans over 4,000 miles away.
Americans, if they think about the leech at all, tend to see it as a scourge of summer camp or a horror of historical medicine. But for microsurgeons, it’s a tool for desperate times — and that’s saying something when spoken by specialists whose schedules are stacked with gruesome mishaps. Our bodies can be torn and contorted in the strangest ways, and their job is to work with what remains: Appendages severed by knives and saws, muscles and nerves ripped by the teeth of dogs, limbs reconfigured by propellers.
These repairs invariably mean dealing with damaged veins. While arteries are thick-walled — the body’s answer to the garden hose — veins are flimsier, harder to suture back into shape. “It’s just like if you were to have moistened toilet paper, one piece over the other, and you’re trying to peel the two pieces apart,” said Dr. Gregory Buncke, director of the Buncke Clinic in San Francisco. “Or like Saran wrap that’s wet and stuck to itself.”
Sometimes, after surgery, a team will notice that the harder half of that plumbing job failed. The arteries work, funneling in oxygen-rich blood, but the veins don’t, leaving the fluid no escape. The skin grows dusky, swollen, and hard. If nothing is done, the tissue will suffocate and die, ruining the graft that a surgeon just spent hours sculpting.
It’s for this scenario that American hospitals keep tanks of leeches. In Europe, they’re advertised as treatments for osteoarthritis, tendinitis, varicose veins, muscular pain, and hemorhoids. The U.S. Food and Drug Administration is less permissive: Here, a leech is regulated as a medical device, cleared only to help with venous congestion after certain surgeries.