Think of maggots feeding on a wound and most people recoil in disgust at the very thought. Through their preferential consumption of dead tissue, however, 'disgusting' maggots decrease the risk of post-operative infections, according to a study reported in Clinical Infectious Diseases.

For many years, maggot therapy was recognized as an effective method of wound debridement — the removal of necrotic and contaminated tissue prior to wound closure. In more recent times however, concerns have been raised relating to the safety of maggot debridement therapy (MDT). MDT typically involves applying dressings containing disinfected maggots — specifically the larvae of the blowfly Phaenicia sericata — to the wounds of patients. To address the safety and utility concerns of this method of debridement, Ronald Sherman and Kathleen Shimoda conducted a retrospective analysis of MDT procedures performed at their hospital over a period of five years. The researchers found that although six (32%) of the wounds that were not pre-surgically treated with MDT developed post-operative infections, not one of the 10 wounds that were treated with MDT developed infections. Further analysis of the data demonstrated that the only factor significantly associated with post-operative wound infections was the absence of pre-surgical MDT.

This study demonstrates that pre-surgical MDT is an effective therapy in preparing wounds for closure. The reasons for the actual reduced infection rate in MDT-treated wounds are not clear, but previous studies have shown that maggots secrete antimicrobial peptides, cytokines and epithelial growth factors that stimulate wound healing. What is clear, however, is that, although the results of this study are encouraging, a large prospective multi-centre clinical trial is essential for a complete understanding of the risks and benefits of MDT.