for National Geographic News
Bandages and ointments infused with essence of maggot may soon be coming to a drugstore near you.
Battlefield medics hundreds of years ago were the first to notice that bloody wounds infested with maggots actually heal faster than "clean" wounds.
(Related: "Nature's Rx" in National Geographic magazine.)
Today hospitals around the world breed selected fly larvae in sterile environments. These "medical maggots" are applied directly to wounds such as ulcers and burns, which are otherwise difficult to heal.
There is no question that the somewhat grim technique works. But how maggot therapy heals has long been a matter of debate.
The secret, according to a new study, is in a fluid secreted by the maggots to help them consume decaying tissue.
In many wounds that are not readily healing, tissue decays and dies, allowing bacteria to thrive. This creates irritation that further prevents proper healing.
"We have produced an enzyme from the maggot fluid with the capacity to remove decaying tissue from the wound, giving the underlying tissue a better chance to heal," said David Pritchard, a researcher working on the project at the University of Nottingham School of Pharmacy in the U.K.
"Now that we understand the 'mechanism of maggots,' we are translating this knowledge to make effective wound-care products."
A bandage impregnated with maggot "juice" is one possibility. But a gel containing maggot enzymes is the most likely product, Pritchard said. Such a gel could be spread over wounds to promote healing.
While the idea might make some patients' stomachs turn, maggot-based medicines aren't expected to have many side effects.
"There are few reports of adverse reactions to maggots, and since the enzymes that we are producing are already secreted by [medical] maggots into wounds, we do not expect adverse reactions to these enzymes," Pritchard said.
Despite the success, working with maggots isn't the sort of job that makes a research team popular with its neighbors, Pritchard added.
"We were initially blamed for a plague of flies in our institute," he said. "But when the fly species was identified, it was found that the flies were [coming] from pigeons which had died inside the roof."
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