Medical maggots don't speed healing of a wound

Maggots are no better in healing wounds than a commonly used gel, a study suggests.

Nurses placed either the worm-like creatures or a hydrogel and surgical dressing on patients' leg ulcers to remove dead, damaged or infected tissue. The maggots cleared away tissue faster, though wounds healed in the same amount of time in both groups, according to the study, published in the British Medical Journal. Maggots were also more painful for patients.

The results surprised lead study author Nicky Cullum, a wound-care researcher in England, and run counter to claims maggots are superior to conventional wound dressing in both cost and healing properties. The researchers found no evidence that maggot therapy should be recommended for routine use on leg ulcers. Maggots were approved for medical use in 2004 in both the U.K. and the U.S.

"Maggots, although they sped the cleaning, didn't speed the healing of the wound," Cullum said in an interview. "Both treatments had a similar cost, but the maggots led to more pain."

The study, the first trial to have randomly assigned patients to either treatment, used the larvae of the green bottle fly. Maggots eat only diseased tissue, a characteristic noticed by people around the world centuries ago. One of the earliest European medical texts, "Hortus Sanitatus," mentioned the use of maggots when it was published in Germany in 1491.

Modern maggot therapy was established by William Baer, a professor of orthopedic surgery at Johns Hopkins University School of Medicine in Baltimore, who observed the success of the treatment in World War I.

Globally, about 50,000 treatments were applied to wounds in 2008, according to the Web site of Monarch Labs, an Irvine, Calif.-based supplier of medical maggots.

The three-year study followed 267 patients with at least one ulcer caused by pressure in the veins. Patients who were given maggots saw their ulcers heal in 236 days compared to 245 days for those who received a gel dressing, though the results were not statistically significant.

The researchers also found that maggots didn't reduce the number of a type of bacterium called MRSA, or methicillin-resistant Staphylococcus aureus.