Certain fly larvae can infest corpses or the wounds of live hosts. Those which are least invasive on live hosts have been used therapeutically, to remove dead tissue from wounds, and promote healing. This medicinal use of maggots is increasing around the world, due to its efficacy, safety and simplicity. Given our low cultural esteem for maggots, the increasing use and popularity of maggot therapy is evidence of its utility. Maggot therapy has successfully treated many types of chronic wounds, but much clinical and basic research is needed still. In this review, the biology of myiasis and the history of maggot therapy are presented, the current status of our understanding and clinical use of medicinal maggots is discussed, and opportunities for future research and applications are proposed.

OBJECTIVE—To assess the efficacy of maggot therapy for treating foot and leg ulcers in diabetic patients failing conventional therapy. RESEARCH DESIGN AND METHODS—Retrospective comparison of changes in necrotic and total surface area of chronic wounds treated with either maggot therapy or standard (control) surgical or nonsurgical therapy. RESULTS—In this cohort of 18 patients with 20 nonhealing ulcers, six wounds were treated with conventional therapy, six with maggot therapy, and eight with conventional therapy first, then maggot therapy. Repeated measures ANOVA indicated no significant change in necrotic tissue, except when factoring for treatment (F [1.7, 34] = 5.27, P = 0.013). During the first 14 days of conventional therapy, there was no significant debridement of necrotic tissue; during the same period with maggot therapy, necrotic tissue decreased by an average of 4.1 cm2 (P = 0.02). After 5 weeks of therapy, conventionally treated wounds were still covered with necrotic tissue over 33% of their surface, whereas after only 4 weeks of therapy maggot-treated wounds were completely debrided (P = 0.001). Maggot therapy was also associated with hastened growth of granulation tissue and greater wound healing rates. CONCLUSIONS—Maggot therapy was more effective and efficient in debriding nonhealing foot and leg ulcers in male diabetic veterans than was continued conventional care.

Medicinal maggots are believed to have three major mechanisms of action on wounds, brought about chemically and through physical contact: debridement (cleaning of debris), disinfection, and hastened wound healing. Until recently, most of the evidence for these claims was anecdotal; but the past 25 years have seen an increase in the use and study of maggot therapy. Controlled clinical studies are now available, along with laboratory investigations that examine the interaction of maggot and host on a cellular and molecular level. This review was undertaken to extract the salient data, make sense, where possible, of seemingly conflicting evidence, and reexamine our paradigm for maggot-induced wound healing. Clinical and laboratory data strongly support claims of effective and efficient debridement. Clinical evidence for hastened wound healing is meager, but laboratory studies and some small, replicated clinical studies strongly suggest that maggots do promote tissue growth and wound healing, though it is likely only during and shortly after the period when they are present on the wound. The best way to evaluate—and indeed realize—maggot-induced wound healing may be to use medicinal maggots as a “maintenance debridement” modality, applying them beyond the point of gross debridement.

In the 21st century, eighty years after William Baer presented his groundbreaking work treating bone and soft tissue infections with live maggots, thousands of therapists around the globe have rediscovered the benefits of maggot therapy. The renaissance in maggot therapy is due in large part to recent technological advancements that have solved or minimized many of the treatment's earlier drawbacks: the need for reliable access to this perishable medical device, simplified application, and low-cost production. Modern dressing materials have simplified the procedure and minimized the risk of escaping maggots. The establishment of dozens of laboratories throughout the world, along with access to overnight courier services in many regions, has made medicinal maggots readily available to millions of people in need. Studies show that fears of patient nonacceptance are unfounded. The medical literature is rapidly growing with scientific evidence demonstrating the efficacy and safety of maggot therapy for a variety of problematic wounds. This article examines how these and other technologies are optimizing the study and application of maggot therapy for wound care.

Results of this prospective study of myiasis differ significantly from those of our analysis of previously published reports and suggest that most cases of human myiasis are caused by noninvasive blowflies laying eggs in preexisting wounds. Five percent of infestations were nosocomially acquired and not necessarily associated with patient neglect.

To define the efficacy and safety of maggot therapy, a cohort of 103 inpatients with 145 pressure ulcers was evaluated. Sixty-one ulcers in 50 patients received maggot therapy at some point during their monitored course; 84 ulcers in 70 patients did not. Debridement and wound healing could be quantified for 43 maggot-treated wounds and 49 conventionally treated wounds. Eighty percent of maggot-treated wounds were completely debrided, while only 48% of wounds were completely debrided with conventional therapy alone (p=0.021). Within 3 weeks, maggot-treated wounds contained one-third the necrotic tissue (p = 0.05) and twice the granulation tissue (p < 0.001), compared to non-maggot-treated wounds. Of the 31 measurable maggot-treated wounds monitored initially during conventional therapy, necrotic tissue decreased 0.2 cm(2) per week during conventional therapy, while total wound area increased 1.2 cm(2) per week. During maggot therapy, necrotic tissue decreased 0.8 cm(2) per week (p = 0.003) and total wound surface area decreased 1.2 cm2 per week (p = 0.001). Maggot therapy was more effective and efficient in debriding chronic pressure ulcers than were the conventional treatments prescribed. Patients readily accepted maggot therapy, and adverse events were uncommon.

No abstract

In traditional medical practice, the larvae of some Diptera: Calliphoridae, notably Lucilia illustris (Meigen), L.sericata (Meigen) and Phormia regina (Meigen), have been employed for maggot therapy, i.e. to help clean lesions antiseptically, especially for treatment of chronic osteomyelitis. This mode of treatment remains appropriate for cases where antibiotics are ineffective and surgery impracticable.