Maggot Therapy: Reviving An Ancient Healing Method

Maggot therapy (MGT), also known as Maggot Debridement or Biotherapy, involves using disinfected green-bottle fly larvae to remove dead tissue from wounds. Despite society's general aversion to insects lacking apparent benefits, this method of treatment has a rich history, featuring accounts of maggots aiding wound healing across different cultures. From the Aboriginal Ngemba tribe in New South Wales to the Mayans of Burma, who soaked bandages in cow's blood to attract these tiny healers, these stories cast maggots as symbols of revitalisation rather than agents of decay.¹

And what better arena to witness a maggot’s work than on the battlefield? Modern medicine's rediscovery of MGT draws from multiple accounts by military surgeons spanning the 15th to 20th centuries. These accounts consistently linked the presence of maggots in wounds to increased survival rates and wound healing. Notably, during the Great War of 1917, orthopaedic surgeon William S. Baer encountered the same experiences as these surgeons and set himself to extensively study the life cycle of the blowfly. Baer pioneered methods for producing sterile maggots, supporting the efficacy of this ancient healing method with the first clinical trials.²

However, the discovery of penicillin led to a decline in MGT, as antibiotics offered practical advantages such as longer shelf life and ease of use, and larvae were not fully understood on a molecular level. Nevertheless, with the rise of antibiotic-resistant bacteria, healthcare professionals revisited MGT, which led to its availability as a therapy on the NHS in 2004.

How do they do it?

The types of maggots used in MGT are not the common household maggots you find in your bins after coming back from holiday, but the humble larvae of the green-bottle fly: Lucilia sericata. Maggots feed via the process of extracorporeal digestion; this is where enzymes that digest proteins are produced by maggots to liquefy dead skin for easy swallowing. This is clinically known as enzymatic debridement. If wounds are successfully cleared, cleaned, and healed, there is huge potential to save patients from amputation of limbs, sepsis, or further infections.

The critical first step is debridement

Debridement is the process of wound clearing; ensuring that all the dead skin is removed allows for new healthy skin to form. Studies have shown that MGT significantly reduces the time to debridement of necrotic skin in comparison to standard therapies.^3,5

Step two: keeping wounds clean

Hospitals prioritise sterility, yet the rise of antibiotic resistance demands effective wound-bacterial burden management. Genetic sequencing of Lucilia sericata has revealed up to 47 genes encoding antimicrobial proteins.⁶ Polat et al. found that Lucilia sericata larvae secretions reduce bacteria levels in wounds, including:

• Staphylococcus aureus (MRSA)⁷
• Escherichia coli (E.Coli)
• Pseudomonas aeruginosa (Pa)⁸

Maggots also contribute to wound cleanliness through ammonia production—a waste product that alkalinises wounds, creating an inhospitable bacterial environment and optimising maggot enzyme activity.

Step three: wound healing

After clearing and cleaning wounds, healing begins with MGT fostering faster new tissue formation. Studies demonstrate that maggots aid wound healing by:

• Producing secretions that promote human tissue growth.⁹
• Physically moving, stimulating wound secretion for cleaning and bacterial dilution.
• Promoting new blood vessel growth.
• Improving oxygen access to vital cells in the wound bed.^10,11

Clinical evidence, including observational trials and case reports, confirms MGT’s effectiveness, particularly in accelerating wound debridement. However, there remains an appetite for further randomised trials to showcase its efficacy concerning antimicrobial effects, wound healing, and its contrast with traditional methods.

Indications

MGT is a versatile procedure suitable for patients with persistent chronic wounds; these have become more prevalent due to increased life expectancy and chronic health conditions. These wounds often affect the legs and feet, such as:

• Diabetic ulcers
• Pressure ulcers
• Necrotic and infected wounds

It’s recommended for static, infected wounds without large blood vessels or arterial wall involvement.^10,12

Safety considerations

Patients understandably have concerns about the safety of MGT, especially when applying live maggots to infected wounds. Healthcare professionals are diligent in evaluating potential risks to ensure safe and beneficial care. They address:

• Risk of maggot escape and infection – modern dressings have reduced this risk, with proper collection and disposal.
• Allergic reactions – patients allergic to ingredients in maggot production or used during larvae disinfection won't undergo MGT.
• Patient selection – MGT isn't suitable for those with bleeding disorders, wounds near arteries, or on blood-thinning medication like warfarin.

After minimising risks, regular patient progress monitoring ensures treatment effectiveness. Some regimens may even be administered at home, depending on the monitoring requirements.¹³

Application and procedure - larvae & pupa & flies! Oh my!

Preparing and sterilising maggots is crucial for MGT. While it may seem counterintuitive to apply living organisms that could potentially introduce infection, the creation of sterile 'medical-grade' larvae is essential. Industry laboratories like BioMonde play a significant role in producing larvae, adhering to strict quality control standards under Good Manufacturing Practices.

The laboratory larvae life cycle

1. Female adult flies will lay up to 3,000 eggs.
2. The eggs are separated, placed on a protein source and sterilised for clinical use.
3. Hatching occurs within 24 hours.
4. Once sterilised, the larvae are ready for either placement into sterilised confinement dressings or for delivery to hospitals for further use.^14,15

Application

Larvae placement and containment methods include:

• Free-range – maggots are applied directly to the wound
• Containment dressings – Le Flap™, place maggots on the wound and cover them with netting to keep them in place.¹⁶
• Confinement dressings – Such as the BioBag™, which resembles a small netted bag, like a tea bag, which confines maggots, reduces patient discomfort and prevents them from crawling over exposed nerves. This also eliminates direct handling for healthcare professionals.¹⁷

After application, treatment duration follows the larvae feeding cycle of 96 hours (4 days). Monitoring the wound's size allows healthcare practitioners to determine how many applications are needed for efficient cleaning. Initially, maggots are only a few millimetres long, like a grain of rice, but they grow to approximately 12mm as they feed.

Patient and medical community perception

Misconceptions about how maggots work and their potential benefits in wound healing have been overshadowed for years by an inherent disgust and by their unsettling link to death and decomposition. Studies have now revealed that healthcare professionals often prove more resistant to the use of maggots than patients themselves. Those undergoing MGT have battled chronic wounds, sometimes for years, making them desensitized to discomfort and are, therefore, more willing to explore unconventional solutions to alleviate their suffering.

Education plays a pivotal role in translating and communicating the accumulating clinical evidence to patients and healthcare professionals alike, and although challenging perceptions has never been easy, a study by Bazalinski et al. showed the importance of education in promoting the use of MGT; revealing that nurses who were more knowledgeable in its benefits were more motivated to implement it.¹⁸

Comparison with modern wound care methods

Wound care has advanced significantly over the years, offering various approaches and technologies for healing and preventing complications. Some common conventional treatments include:

• Surgery
• Dressings like gauze and hydrogel
• Antibiotics
• Ultrasound therapy
• Skin grafts

Traditional chronic wound treatments often result in delayed healing due to frequent bandage changes, disrupting the healing process. MGT, with minimal disruption and no antibiotics, has shown comparable or superior results to modern methods. It improves debridement and healing times, lowers infection rates, and reduces the need for initial or subsequent major amputations.

Cost-effectiveness

Studies evaluating the cost-effectiveness of MGT in comparison to routine care methods conclude that there are significant savings that can be made in adopting MGT over costly conventional wound dressings.

Examples where savings can be made include:

• Nurses performing MGT instead of physicians, reducing labour costs.
• Lower average costs for MGT compared to conventional wound dressings.
• Reduced reliance on antibiotics.
• Replacing surgical debridement, which requires operating theatre expenses.^19,20

Current challenges

MGT is often only suggested after all other avenues of treatment have been explored. However, there are ongoing challenges to incorporate it into mainstream wound care:

• Standardized Protocols: Currently, there is no universally accepted set of guidelines for MGT. Different healthcare institutions and practitioners have their protocols, which can vary significantly in terms of maggot species used, application methods, dressing materials, monitoring procedures, and treatment duration. This lack of consistency makes it challenging to compare and replicate research findings and clinical outcomes.
• High-quality medical education: Access to interdisciplinary training programs specific to MGT is limited. Coordinating programs that offer education and hands-on experience can improve the safety and efficacy of applications.²¹

While education and training are crucial for introducing MGT to mainstream healthcare, it's important to consider that many institutions face resource constraints. This can impact the ability to introduce MGT in countries that could benefit the most, especially those with limited access to expensive conventional treatments.

That’s all we’ve maggot time for

Maggot therapy (MGT) is a historical and innovative approach to wound healing. It uses disinfected green-bottle fly larvae to remove dead tissue, with roots tracing back to ancient cultures. While antibiotics initially led to a decline in MGT, the rise of antibiotic-resistant bacteria has reignited interest, making it available as a therapy option.

MGT functions by enzymatic debridement, efficiently clearing dead skin and promoting healing. It also reduces bacterial burden and prevents further surgical intervention such as amputation. Maggots have many unique attributes, and their integration with contemporary wound care showcases a promising future where the revitalisation of an ancient therapy will optimise current treatment outcomes, provide novel therapeutics that reduce our reliance on antibiotics, and challenge medical prejudices in the use of alternative therapies.

Summary

Maggot therapy (MGT) utilizes disinfected green-bottle fly larvae to remove dead tissue from wounds, drawing from ancient healing practices. Its resurgence in modern medicine, driven by military surgeons' experiences, showcases its efficacy in enzymatic debridement, reducing bacterial burden, and promoting wound healing. Despite initial aversion, MGT offers a promising alternative for treating chronic wounds like diabetic ulcers, with careful patient selection and monitoring. Standardized protocols and education are essential for its integration into mainstream healthcare, offering cost-effective solutions and challenging medical prejudices.