A Truly Revolting Treatment Is Having a Renaissance

In its larval stage, Lucilia sericata looks unassuming enough. Beige and millimeters long, a bottle-fly grub may lack good looks, but it contains a sophisticated set of tools for eating dead and dying human flesh. The maggots ooze digestive enzymes and antimicrobials to dissolve decaying tissue and to kill off any unwanted bacteria or pathogens. Lacking teeth, they use rough patches on their exterior and shudder-inducing mandibles (called “mouth hooks”) to poke at and scratch off dead tissue before slurping it up.

This flesh-eating repertoire is hard enough to stomach in the abstract. Now imagine hosting it on your skin. “Not everyone, psychologically, can deal with that sensation and knowing maggots are chewing on their flesh,” Robert Kirsner, the director of the University of Miami Hospital Wound Center, in Florida, told me. This is the barrier that advocates of maggot therapy face: the emotional gravity of pure human revulsion.

How to convince a maggot-hesitant patient? “I would say, ‘Please give me just 24 hours of your life,’” says Kosta Mumcuoglu, a parasitologist and medical entomologist at the Hebrew University of Jerusalem. “Tomorrow at this same time, I will come back, and you can decide how to continue.” In that period, a smattering of maggots, about 32 to 50 per square inch of wound, can start cleaning out dead and dying slough and encourage remaining viable tissue to heal.

In the U.S., some 6.7 million people have chronic wounds that—for one reason or another—refuse to heal for months, even years. On its own, a chronic wound can seriously diminish a person’s quality of life and eventually, if left untreated, lead to loss of a limb. In 2009, after years of improvement, rates of lower-limb amputations on diabetic adults in the U.S. (one of the country’s most preventable surgeries) began to slip in the wrong direction, growing 50 percent by 2015, with Black, low-income, or underinsured patients most likely to undergo amputation. Data suggest that, by a conservative estimate, Medicare spends an estimated $28.1 billion annually on wounds. These are “very dramatic” figures, says Steven Kravitz, the president of the Academy of Physicians in Wound Healing, “and they’re not getting better.”

In some ways, this is an old problem—festering wounds are one of the most archaic threats to human life—and maggots are an old solution. Maya healers dressed lesions with cattle-blood-soaked bandages to attract flies and make wounds squirm with maggots; legend has it that Genghis Khan traveled with a wagon of larvae for wounded soldiers. Safe to say, today’s patients and doctors are more comfortable with the aseptic medical practices developed over the past century. “Our expectation is that medicine can do everything,” says David S. Jones, an epidemiologist and a historian of medicine at Harvard. “We have earned our worm-free existence.”

But with rates of chronic conditions, diabetic ulcers, and hospital superbugs rising, troublesome wounds are a very current threat, pressing clinicians and patients to reconsider the role of maggots. With new approaches to harnessing their powers and new strategies for mitigating their yuck factor, maggots might shed their reputation as an erstwhile cure and take their place in the future of medicine.

At any given moment, trillions of maggots, or fly larvae, are wriggling across North America. A fly mother can smell decomposition from up to 10 miles away and arrive within minutes to lay her offspring. (In some species, she will bury herself six feet underground to get to a dead body.) Scientists have witnessed adult and juvenile flies penetrate seemingly sealed barriers—including coffins and suitcase zippers—with ease. One can find maggots at lake bottoms, in camel nostrils and petroleum pits, on toadstool mushrooms and spider abdomens, and of course, in virtually every burial ground most everywhere in the world, according to the London Natural History Museum senior curator Erica McAlister, who also wrote The Inside Out of Flies.

During this stage of a fly’s life (in many species, its longest), the larva is driven by a two-pronged mission to eat as much as possible and avoid being eaten. “To this end,” McAlister writes, “its body is nothing more than a basic eating machine, with no wings, no genitalia and no true legs.” In other words, maggots are hungry bags of goo traveling along streams of enzymatic saliva in search of decaying flesh.

In modern medical history, these living goo bags were carefully sterilized and used in clinical settings for only one short decade, the 1930s, despite centuries of observations about their penchant for flocking to wounds. “My flesh is clothed with worms and clods of dust; My skin closeth up, and breaketh out afresh,” Job recounts in the Old Testament. In the 15th century, the eminent Iranian physician Bahaodole Razi suggested that when a wound “generates worms,” doctors should “give them some time to feed.” The French surgeon and Napoleonic buddy Baron Dominique-Jean Larrey recalled that during a 19th-century expedition in Syria, blue-fly larvae’s speedy growth “greatly terrified” wounded soldiers. These and many other historical accounts describe maggot infestations as lucky—albeit revolting—accidents and not targeted medical interventions.

Not until the Civil War did the Confederate surgeon John Forney Zacharias perform, “with eminent satisfaction,” one of the first documented intentional applications of maggots. “In a single day, they would clean a wound much better than any agents we had at our command,” he wrote. But his satisfaction still didn’t translate into a wide appreciation of maggots. Decades later, during World War I, the military surgeon William Baer noted with astonishment that two seriously injured soldiers had not suffered from fever, septicemia, or blood poisoning even though they had been hidden by brush and overlooked for an entire week. Baer’s second shock: thousands of “abominable looking creatures” swarming their wounds. “The sight was very disgusting,” he wrote. A saline wash revealed a final surprise. “Instead of having a wound filled with pus,” Baer wrote, “these wounds were filled with the most beautiful pink granulation tissue that one could imagine.”

At the time, antiseptic tools were still inadequate and deaths from open wounds remained stubbornly high. Rather than leave his wartime observations to the annals of history, Baer dedicated himself to exploring how to systematically—and safely—apply maggots to wounds. As an orthopedic surgeon at Johns Hopkins University, he ran a trial on 21 patients with persistent bone infections; within two months of beginning the maggot treatment, all of the patients’ wounds had healed. Baer died just two years later, in 1931, but in the decade that followed, hundreds of U.S. hospitals added maggots to their wound-healing toolkit.

The larvae therapy’s popularity was short-lived. In 1928, as Baer was running his clinical trials, Alexander Fleming discovered penicillin. The mass production of antibiotics by the mid-’40s quickly shunted medical maggots aside. “Fortunately maggot therapy is now relegated to a historical backwater,” opined the University of Sheffield microbiologist Milton Wainwright in 1988, “a therapy the demise of which no one is likely to mourn.”

Maggots’ modern renaissance began shortly thereafter, in the early ’90s. Up until that time, Mumcuoglu, the parasitologist, was more interested in the many ways that bugs like mites, lice, and ticks could wreak havoc on the human body. Then, one day, a colleague approached Mumcuoglu about a patient who had already lost his right leg and risked his left to amputation. “This physician didn’t know what to do,” Mumcuoglu recalls, and asked about the possibility of maggot therapy. Mumcuoglu had never tried it, but together they quickly found, sterilized, and applied maggots to the wound. To everyone’s surprise, the patient’s remaining leg was saved.

From that moment, Mumcuoglu began to evangelize maggot therapy as a valid wound-care option when other, more palatable alternatives had failed. Already, maggots were experiencing something of a global revival. In South Wales, the Biosurgical Research Unit at Princess of Wales Hospital began selling larvae in 1995, followed shortly by German and Belgian maggot factories. By 1996, the newly formed International Biotherapy Society began hosting annual meetings about larval therapy and other biologically aided treatments. And in California, Ron Sherman, an entomologist turned doctor turned maggot advocate, was running studies on maggot therapy at UC Irvine. After the Food and Drug Administration began approving maggots as a prescription-only medical device, Sherman’s lab was one of the first in the country to obtain federal permission to sell them, in 2004.

By 2008, maggot therapy was being administered about 50,000 times annually worldwide, as a growing body of research continued to demonstrate why the stomach-turning approach was worth tolerating. In a three-year randomized clinical trial, for example, University of York scientists found that larvae debrided leg ulcers significantly faster than standard wound-healing gels did. In another study of foot-ulcer treatments, researchers at Trafford College, near Manchester, concluded that maggot therapy was significantly better than gels at reducing the area of a wound. Individual case studies have also described the effectiveness of maggot therapy for severe electrical burns or methicillin-resistant Staphylococcus aureus (MRSA) infections. A 2012 study conducted at two French hospitals found that maggots could outperform scalpels when it came to quickly clearing dead tissue from nonhealing wounds. During the COVID-19 pandemic, University of Southern California surgeons demonstrated that maggot therapy could even be conducted via telemedicine.

Kravitz told me that by now, the evidence is clear: “Maggot therapy is a good way of treating lots of wounds. There’s very little downside to it.” It’s by no means a cure-all, he said, but for the worst-of-the-worst wounds, it is a worthwhile intervention to deploy.

Still, our overwhelming bias against the technique has largely prevailed. “Their use in the United States has been slight, in part because of squeamishness,” The New York Times noted in 2005, shortly after maggots received FDA clearance. “People talk about it, but for many, I don’t think it’s a go-to,” Kirsner said. “You want to position wound centers as being cutting-edge or novel—not old-fashioned or archaic.”

A cohort of scientists and entrepreneurs is trying to do just that.

Many medical offices, for example, now contain maggots in “biobags” thin enough for larval secretions to pass through but thick enough to hide the grubs from view (and keep them from escaping). Other start-ups have tried to circumvent actual bug application by developing gels containing maggot enzymes. Entomologists at North Carolina State University have even genetically tweaked blowfly maggots to also produce a human growth factor that could boost their healing powers.

But for the most part, advocates of maggot therapy are left to depend on the power of testimonials—a strategy with a long track record. “Nothing short of experience could convince them,” wrote Baron Larrey of his accidentally maggot-infested soldiers. Left to do what they do best, maggots will frequently prove that they’ve earned their keep. “You saw it once,” Mumcuoglu says, “and it was enough to convince you.”

Limited research supports this strategy and suggests that disgusted patients will still give maggots a go—especially when faced with an extreme alternative, such as amputation. In a 2002 to 2003 investigation of the treatment’s “yuk factor,” Dutch doctors found that 94 percent of surveyed patients who had received maggot therapy said they would recommend it to others, despite unpleasant side effects such as odor, pain, and itching. Being temporarily infested ultimately compares favorably to life accompanied by the constant smell and sight of decaying flesh. “Worms growing in your skin is one of the most appalling things I can imagine,” says Jones, the Harvard historian of medicine. “But these maggots are the lesser of two evils. You’re not comparing maggots to nothing; you’re comparing it to this other, barbaric thing.”

Living with a festering wound forces people to confront the same uncomfortable point as maggots do: We all live in bodies that will eventually decay, and once they do, we are all little more than larvae food. Whether we like it or not, maggots await us on the other side of what the cardiologist and poet John Henry Stone described as “the rigid final fact of a body.” What if maggots could help some of us enjoy better lives before we reach that terminus?

That’s the terrible beauty of this solution. By leaving a space open in modern medicine for maggots, we have to face more squarely the natural symbiosis that affords us existence. We don’t usually think of our body as an ecosystem composed of only 43 percent human cells—we’re made more of bacteria, viruses, fungi, and archaea than anything else. From that perspective, maggots are simply another guest in our teeming anatomy—a healer that we’re lucky to cohabit alongside.