MAGGOT DEBRIDEMENT THERAPY (MDT)
Compiled & Edited by-- DR RAJESH KUMAR SINGH, JAMSHEDPUR
History of Maggot Therapy
For centuries, the beneficial effects of maggot-infested wounds were noted by military surgeons who observed that injured soldiers abandoned on the battlefield fared better and that their wounds healed faster when those wounds were infested with maggots.7Himself having observed maggot-infested wounds during his service in World War I, the orthopedic surgeon, William Baer, was the first to apply maggots systematically to nonhealing wounds while a professor at Johns Hopkins and Children’s Hospital in Baltimore, Maryland. Baer presented his preliminary results in 1929 and his entire work in maggot therapy—treating over 100 children with osteomyelitis and problematic soft tissue wounds—was published posthumously in 1931
Medical grade maggots are a biological therapy that can yield excellent results in the most difficult of wound cases. Application of medical maggots was first described by William Baer in the 1929 (before the widespread usage of antibiotics). I consider them one of the most useful revivals of old to modern medicine, and they are currently gaining popularity for management of the most difficult types of human wounds (diabetic ulcers, pressure ulcers, and non-healing wounds).
In the equine world, maggots are most often used for severe infections within the hoof, but may have many other uses. Their main application is for use in necrotic or infected wounds. Maggots naturally debride and consume necrotic (dead) tissue with greater precision than a scalpel. They achieve this by secretion of a spectrum of proteolytic digestive enzymes to liquefy (and subsequently consume) necrotic tissue. Most wounds are debrided in 48-72hr, during which time the maggots rapidly increase in size. Once all necrotic tissue has been eliminated, maggots will migrate from the wound or expire (they do not disturb healthy tissues). Medical maggots also help disinfect wounds by secretion of various antimicrobial molecules, ingestion of bacteria, and disruption of biofilms. Aside from debriding and disinfecting the wound, maggots are also thought to stimulate more rapid growth of healthy tissue.
The specific fly larvae used for maggot therapy are from the ‘blow fly’ (Calliphoridae). They are grown and delivered germ free so there is minimal/no risk of transmitting disease to the wound in which they are applied.
Maggot Therapy Today
By the end of the 1980s, antimicrobial resistance was increasingly common, pressure ulcers and diabetic foot ulcers were on the rise, and conventional wound care was noticeably inadequate for an increasing number of recalcitrant wounds. This was the backdrop for a series of research questions: How would maggot therapy compare to modern wound care treatments? Why was MDT now used only as a “last resort” Should MDT be used earlier in the course of treatment, especially if it compared favorably to conventional therapy? The first controlled clinical studies of maggot therapy would address these questions. But before those studies could be carried out, and before widespread use of maggot therapy was imaginable, several technical challenges first had to be overcome.
Medicinal Maggots and How They Work
Maggot therapy is essentially a controlled therapeutic myiasis (maggot infestation on a live host). It is controlled by selecting a safe and effective species and strain, by chemical disinfection to make the maggots germ-free, by containing the maggots within special dressings that prevent them from leaving the wound unescorted, and through quality control measures throughout the breeding and production processes. Not all species are safe and effective. The maggots cleared for marketing in the United States belong to the (currently named) LB-01 strain of Phaenicia (Lucilia) sericata.
Maggots are applied to the wound at a dose of 5–10 larvae per square centimeter of wound surface area and are left within their dressing for 48–72 h. At that point they are satiated, finished working, and can be removed. Clinical and laboratory studies have identified four major actions of medicinal maggots on wounds:
Medicinal maggots are as precise in their debridement as a highly skilled microsurgeon, as attentive to their hosts’ wounds as the most dedicated wound-care nurse. It is no wonder that they have found their way into the hearts and wounds of so many.
Despite our low cultural esteem for maggots, more and more clinicians and patients are turning to medicinal maggots for assistance with their wound healing. For most, the drawbacks of maggot therapy pale in comparison to the remarkable efficacy in treating even the most recalcitrant wounds.
By combining the wisdom of the past with the technology of the present, we have solved many of maggot therapy’s drawbacks. Now vets of developed countries are bringing medicinal maggots back into their hospitals and clinics to help patients’ most troublesome wounds. Modern dressing materials have simplified the maggot therapy procedure and minimized the risk of escape. The establishment of laboratories throughout the world, along with access to overnight courier service in many regions, has made medicinal maggots readily available to millions of livestock farmers.
