Dr. Ravi Kamble, a Brooklyn, N.Y.-based podiatrist who specializes in wound care, first got interested in maggots as a child. His father, a general surgeon, would tell him how poor people in India often had wounds infested with the larvae.
“He would tell me as an aside that by removing the maggots you were actually doing a disservice to the person because maggots actually helped clean the wound. That fact always stuck in my head,” Kamble says.
During medical school, the young Kamble even proposed a research project using maggot therapy -- and “was laughed out of the room” by his professor.
Then, late in 2005, Kamble treated Ramon Rivera, a 54-year-old diabetic with a serious foot ulcer -- gangrenous, with a severe infection reaching down to his bone. “I was consulted late in the process, so everyone was already assuming below-the-knee amputation,” Kamble says. The proposed cut line was already drawn on Rivera’s leg.
But Rivera was resisting. “I felt very depressed. I cried. I didn’t want to lose my leg -- that was the good leg. I told them no,” Rivera said.
Rivera was lucky in that he had sufficient blood supply to salvage his very infected limb -- and was being examined by someone willing to consider an alternative treatment.
Kamble decided to try maggot therapy.
When he discussed the proposal with his medical staff, he met with resistance. “The nurses refused to touch the patient,” he said. Rivera, however, was happy to try the treatment.
About 500 sterile fly larvae were placed directly on the wound and then covered. They were removed a few days later after they’d fed on the dead tissue, then new maggots applied.
The therapy worked. “Before treatment, you could see all the way down to the bone. Now he has tissue forming over it,” Kamble says. Tissue, according to the textbooks, is not meant to regrow over exposed bone. “It shows you that textbooks are never completely correct,” Kamble says.
The ulcer hasn’t completely healed over the heel, but the rest of the wound has mended nicely. Rivera still sees Kamble as an outpatient for regular dressing changes and wound-cleansing (but no more maggots).
Kamble acknowledges that the use of free-range maggots has practical limitations. “I was literally chasing maggots across the floor,” he says. Maggot-chasing need not be necessary, however: In a 2002 issue of the journal Dermatology, German researchers reported the use of maggots combined with a “biobag” -- a little pocket containing the larvae that allows secretions to pass through, making for a much easier and cleaner -- but still efficient -- application.
Maggots secrete enzymes that help them feed on the wound, leaving healthy skin alone. This makes them optimal biosurgical tools for cleaning a wound, Kamble says. They also seem to tackle wound infections by ingesting the wound bacteria. Early clinical evidence suggests that they could be used against resistant strains of bacteria such as methicillin-resistant Staphylococcus aureus, or MRSA.
Not all species of maggot are suited for medical use, as some can attack healthy tissue. The favored species are free-range larvae of the green bottle fly -- Lucilia sericata -- which prefer dead tissue and do not reproduce in the wound.
Maggots were cleared as “medical devices” by the Food and Drug Administration in January 2004, and the therapy is currently reimbursable by Medicare. The practice is growing by about 25% per year in the U.S., says Dr. Ronald Sherman, a pathologist at UC Irvine who has been breeding and studying maggots for years.
“Published studies indicate that about 40% to 50% of wounds treated with maggot therapy as the last alternative before amputation were healed with maggot therapy, and the limbs were saved,” Sherman says. “That’s a lot of legs and feet we might be able to save each year -- although most patients I know would be glad to save just one or two.”