Introduction

While maggots will always have an image problem, they have a lot to offer the field of medicine in the 21st century. Maggot Debridement Therapy (MDT) is an old remedy that has been revised and proven to be invaluable in cleansing non-healing wounds. This simple procedure involves the placement, using restrictive dressings, of live disinfected maggots into non-healing wounds to provide for cleansing of necrotic tissue and initiation of the healing process.


The History of MDT

For centuries, maggots (which is the immature stage of a fly) were known to have beneficial effects on wounds. Ambroise Paré is credited to be the first to note his observations in 1500's. Throughout military history many other positive comments have been recorded in regard to maggot infested wounds by military surgeons that attended wounded soldiers. However, it wasn't until the 1920's that therapeutic experimentation with maggots was instigated by William Baer, a clinical professor in orthopaedic surgery at the Johns Hopkins University in Baltimore, Maryland, whose unorthodox methods were successful in the treatment of osteomyelitis and pyogenic wounds. His methodology of MDT was adopted and routinely used in over 300 hospitals in the USA throughout the 1930's and early 1940's. Thereafter, with the introduction of penicillin and other modern surgical procedures, MDT was replaced in the late 1940's.

MDT, the Modern Pioneers

The 1980's brought an increase of bacterial resistance to antibiotics, and MDT was revisited as a procedure to assist in the treatment of non-healing wounds that were recalcitrant to antibiotics and when surgical intervention was not an option. Dr Ronald Sherman, and associates from the Veterans Affairs Medical Centre, California, pioneered the reintroduction of MDT. His clinical trials indicated that MDT was several times more efficient at debriding infected and gangrenous wounds (and healing them more rapidly) when compared with other modern non-surgical treatments. In the last 15 years, thousands of patients with bedsores, leg ulcers, diabetic foot wounds and post surgical infections have been successfully treated by MDT. At present, health care facilities in the UK, Europe and the USA now produce thousands of medicinal maggots per week for therapists. In the UK alone, MDT has been estimated at saving the national health system over one billion dollars annually, and is now recognised as a procedure that can be officially prescribed and claimed on health care benefits.

How MDT Works

Mystery still surrounds the unique way that maggots 'nurse' wounds as they actively consume dead tissue and fluids. As they cleanse the wound site the maggots exude an antibacterial agent that has a wide spectrum of activity against many resistant pathogens. They also possess diverse proteolytic enzymes, which are capable of digesting bacteria. The mechanical feeding of the maggots and the reduction of necrotic tissue changes the wound's environment from an acid to a more alkaline pH, which assists in stimulating healthy granulated tissue.

How to obtain MDT in Australia

Persistent requests for sterile maggots from throughout Australia encouraged the Department of Medical Entomology at ICPMR to maintain a colony of the blow fly Lucilia sericata (the species most widely used for MDT) and establish a procedure for surface sterilisation of the maggots. Based on Ronald Sherman's methodology we now supply (with cost recovery) disinfected maggots on request for local, interstate and overseas patients.

Contact details for the supply of MDT:

Department of Medical Entomology, ICPMR
Westmead Hospital
WESTMEAD NSW 2145
Ph: 02 9845 7265
Fax: 02 9893 8659

Note that maggots can be delivered anywhere, although a service charge will be added. Please contact the Department for pricing details.

Conclusion

Although not all patients are suited to this therapy, MDT is an efficient, low cost alternative method to cleanse and promote the healing of chronic soft tissue wounds before they progress to a stage where amputation is the only alternative. Although acceptance of MDT is not yet widespread in Australia, perhaps a new image of maggots is slowly emerging wherein they are an effective and economic means of treating wounds and saving limbs for patients in our health system!

Further Reading

R.A.Sherman, M.J.R.Hall, S.Thomas. Medicinal Maggots: An Ancient Remedy for some Contemporary Afflictions. Annual Review of Entomology, 2000, 45:55-81.

Church, J.C.T., Larva Therapy in Modern Wound Care : A Review. Primary Intention. May: 63-68. 1999.

L.M. Vistnes, M.S.RitaLee, G.A.Ksander, Proteolytic activity of blowfly larvae secretions in experimental burns. Surgery, Nov, 1981.

Sherman, R.A., Maggot Debridement in Modern Medicine. Infections in Medicine. Sept: 651-656. 1998.

Teich, S., & Myers, R.A.M., Maggot Therapy for Severe Skin Infections. Southern Medical Journal. Vol. 79, No. 9, 1153-1155, 1986.

Web Links

http://www.ucihs.uci.edu/com/pathology/sherman/home_pg.htm (Ronald Sherman's MDT web site)

http://www.smtl.co.uk/ (LarvE Biosurgical Research Unit, Wales)