The larvae of the greenbottle blowfly (Lucilia sericata) feast on the bacteria and dead tissue in chronic wounds, cleaning out the wound and giving it more of a chance to heal. This is an ancient therapy, used since Biblical times, but fell out of favor with the invention of antibiotics. However, the rise of drug-resistant bacteria, combined with skyrocketing rates of chronic wounds from diabetes, has led to a resurgence of interest in using creepy-crawlies as treatment, usually referred to these days as maggot debridement therapy or larval therapy.

Although larval therapy had been studied in the lab, few clinical trials had tested it head-to-head against more modern surgical techniques. So although Marineau agreed to try the maggots, she had no idea whether they would actually work for James.

She also had no idea how to use maggots, and had to be talked through the procedure over the phone. But it worked perfectly. “We had amazing success with him,” she says. “We were just astounded.” Lots of medical products hype the wonders they can work for patients, but Marineau says maggots are one of the only things that “really blow your mind at what a big difference they can make.”

Marineau received the maggots via overnight mail from Monarch Labs in Long Beach, California. As she placed them one by one on James’s foot in early 2009, she became the latest in a long series of healers. Cultures around the world, including the Maya of Central America, Aboriginal tribes in Australia, and the Myanmar Hill People, have used maggots to treat wounds.

Much of the historical writing on the role of maggots in helping wounds heal revolves around battlefield injuries. Although such wounds can and do kill outright, the majority of deaths from war injuries have been caused by infection. Festering wounds often attract blowflies looking for a spot to lay their eggs, which then hatch into larvae. Napoleon’s battlefield surgeon, Dominique Larrey, noted in an 1832 book that they were “greedy only after putrefying substances, and never touch the parts which are endowed with life.” And they were not just harmless but helpful, by “cutting short the process of nature” to heal wounds more quickly. Despite Larrey’s advice, though, his wounded soldiers were annoyed and terrified by the larvae: “[N]othing short of experience” would convince them to trust the insects.

While Larrey noticed their benefits, he hadn’t deliberately placed blowfly larvae on the wounds. The first documented intentional use of maggots in modern times came during the American Civil War. Confederate physician John Forney Zacharias reported: “During my service in the hospital at Danville, Virginia, I first used maggots to remove the decayed tissue in hospital gangrene and with eminent satisfaction. In a single day, they would clean a wound much better than any agents we had at our command. I used them afterwards at various places. I am sure I saved many lives by their use, escaped septicaemia, and had rapid recoveries.”