What is the optimal treatment time for larval therapy? A study on incubation time and tissue debridement by bagged maggots of the greenbottle fly, Lucilia sericata

Maggot therapy for resistant infections: the disconnect between scientific evidence, clinical acceptance and practice

OBJECTIVE

Practitioners and scientists are re-examining marginalised wound care therapies to find strategies that combat the growing problem of antimicrobial resistance (AMR) without compromising patient outcomes. Maggot therapy (MT) makes up just an estimated 0.02% of UK's National Health Service spending on wound care. This study aims to uncover why MT is not used more often, despite its affordability and high level of efficacy for both debridement and disinfection, particularly in the context of AMR infections, and to determine what can be done to ensure MT is more effectively used in the future to improve patient outcomes and manage the growing problem of AMR.

METHOD

For this investigation, a qualitative review of case studies using MT against AMR infections and a quantitative analysis of randomised control trials (RCTs) were performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework.

RESULTS

Analysis showed that MT is highly effective against a range of infections and wound types, and compares well against conventional therapies. The low use of MT may be due in part to the documented 'yuck factor', often associated with maggots as well as misconceptions around the cost, efficacy and accessibility of MT. To overcome these factors, more RCTs on the spectrum and efficacy of MT across various clinical manifestations are needed, as well as professional and public engagement campaigns.

CONCLUSION

MT is an underused therapy, particularly regarding AMR infections, and expanding its use in these circumstances appears warranted. MT could play a vital role in conserving the efficacy of the existing pool of antimicrobials available and should be considered in the development of antimicrobial stewardship programmes.

DECLARATION OF INTEREST

This work was supported by the Swansea Employability Academy, Swansea University (internal funding). The authors have no conflicts of interest to declare.

Use of biosurgery for the treatment of foot ulcers infected with therapy-resistant bacteria: a case report

Biosurgery (larval therapy) has been used for centuries. However, in recent times, this treatment has been replaced with the use of antibiotics for the treatment of wounds. Due to increasing antibiotic resistance, larval therapy is once again coming to the fore as an effective and efficient treatment. Due to the increasing ageing population, along with an increase in patients with arterial occlusive disease, diabetes and immobility, the number of patients with hard-to-heal wounds will increase. The stressors associated with wounds, such as pain, limited physical functionality, depression and social withdrawal, have a negative impact on patient quality of life. This case report documents the performance of biosurgery in a patient with multimorbidities.

Larval Wound Therapy: Possibilities and Potential Limitations-A Literature Review

Patient-centered care (PCC) is recognized as a standard in healthcare for determining high quality. Honoring patients' values, experiences, needs, and preferences in devising, coordinating, and delivering care underscores the enhancement of the therapeutic rapport between patients and healthcare providers. Wound treatment involves a multi-stage process encompassing diagnostics and local wound dressing, which reduces the risk of infection through a coordinated interdisciplinary team. Within this team, nurses undertake specific professional functions and roles. The implementation of local therapy using innovative and scientifically substantiated methods may be hindered by a deficit of knowledge or inappropriate knowledge among staff and patients themselves. This study presents the challenges concerning the care of patients with chronic wounds treated using Lucilia sericata larvae, based on a review of the current scientific literature. A critical analysis of the literature spanning from 2002 to 2022 was conducted using the Medline, PubMed, Cochrane, and Termedia databases, employing keywords such as "maggot debridement therapy" in relation to acceptance and perception. As a result of the preliminary selection, 472 papers were identified, of which 12 publications were included in the development of this concept. The acquired data were organized and presented in the concluding section in the form of tables, accompanied by descriptions and references to individual studies. Negative psychological and somatic sensations were among the most prominent challenges among patients treated with Maggot Debridement Therapy (MDT). Pain related to peripheral ischemia or infection in this group of patients requires pain prophylaxis, including hyperalgesia and allodynia, in order to improve method tolerance. On the other hand, augmenting patients' understanding of MDT diminishes negative emotions, reinforces positive behaviors, and mitigates anxiety levels. MDT constitutes an effective and safe method. Its widespread use for chronic wounds requires substantial knowledge among healthcare professionals and patient education, along with that of their caregivers, to develop a positive attitude.

How Rearing Systems for Various Species of Flies Benefit Humanity

Flies (Diptera) have played a prominent role in human history, and several fly species are reared at different scales and for different beneficial purposes worldwide. Here, we review the historical importance of fly rearing as a foundation for insect rearing science and technology and synthesize information on the uses and rearing diets of more than 50 fly species in the families Asilidae, Calliphoridae, Coelopidae, Drosophilidae, Ephydridae, Muscidae, Sarcophagidae, Stratiomyidae, Syrphidae, Tachinidae, Tephritidae, and Tipulidae. We report more than 10 uses and applications of reared flies to the well-being and progress of humanity. We focus on the fields of animal feed and human food products, pest control and pollination services, medical wound therapy treatments, criminal investigations, and on the development of several branches of biology using flies as model organisms. We highlight the relevance of laboratory-reared Drosophila melanogaster Meigen as a vehicle of great scientific discoveries that have shaped our understanding of many biological systems, including the genetic basis of heredity and of terrible diseases such as cancer. We point out key areas of fly-rearing research such as nutrition, physiology, anatomy/morphology, genetics, genetic pest management, cryopreservation, and ecology. We conclude that fly rearing is an activity with great benefits for human well-being and should be promoted for future advancement in diverse and innovative methods of improving existing and emerging problems to humanity.

Reappraisal and updated review of maggot debridement therapy in chronic lower extremity ulcers

BACKGROUND

Dating back to the mid-1500s, maggot debridement therapy (MDT) has been a viable treatment modality for chronic wounds. In early 2004, the sterile larvae of Lucilia sericata received FDA approval for medical marketing for neuropathic, venous, and pressure ulcers, traumatic or surgical wounds, and nonhealing wounds that have not responded to standard care. However, it currently remains an under-utilized therapy. The proven efficacy of MDT begs the question if this treatment modality should be considered as a first-line option for all or a subset of chronic lower extremity ulcers.

OBJECTIVE

This article aims to address the history, production, and evidence of MDT and discuss future considerations for maggot therapy in the healthcare field.

METHODS

A literature search using the PubMed database was conducted using keywords, such as wound debridement, maggot therapy, diabetic ulcers, venous ulcers, among others.

RESULTS

MDT reduced short-term morbidity in non-ambulatory patients with neuroischemic diabetic ulcers and comorbidity with peripheral vascular disease. Larval therapy was associated with statistically significant bioburden reductions against both Staphylococcus aureus and Pseudomonas aeruginosa. Faster time to debridement was achieved when chronic venous or mixed venous and arterial ulcers were treated with maggot therapy versus hydrogels.

CONCLUSIONS

The literature supports the use of MDT in decreasing the significant costs of treating chronic lower extremity ulcers, with emphasis on those of diabetic origin. Additional studies with global standards for reporting outcomes are necessary to substantiate our results.

A human tissue-based assay identifies a novel carrion blowfly strain for maggot debridement therapy

Maggot debridement therapy (MDT) is a form of therapeutic wound treatment in which live fly larvae are used intentionally to debride necrotic tissues. MDT has been widely used to treat chronic wounds in humans or animals, such as diabetic foot ulcers. Larvae of a carrion blowfly, Lucilia sericata (green bottle fly), debride wounds by consuming necrotic tissue and removing pathogenic bacteria, promoting effective wound healing. Most medical L. sericata strains were initially collected from natural environments using animal meat as bait and reared on artificial protein-rich media or ground meat. It remains to be examined which strain would be more appropriate for MDT, whereas any method for evaluating the fly’s therapeutic potential in humans has not been available. A feeding assay was developed using minced human tissues obtained from surgical waste. To establish L. sericata strains highly eligible for MDT, carrion fly larvae were collected from 45 corpses subjected to forensic autopsy (such as decomposed bodies). Four corpse-derived L. sericata strains were obtained and evaluated using the feeding assay. One strain showed that its feeding activity was 1.4 times higher than the control strain used in conventional MDT. The body length of the adult fly of the corpse-derived strain was longer than the control, which was consistent with the observation that its cell size was enlarged. The human tissue-based assay developed in this study accurately evaluated the ability of fly larvae to debride necrotic wounds. The L. sericata strain newly established from human corpses harboring high feeding activity may offer a clinically significant improvement in MDT.

The role of debridement in wound bed preparation in chronic wound: A narrative review

Objective

To provide an overview of the types of wound debridement and update the available scientific consensus on the effect of wound debridement.

Methods

The articles were searched through CINAHL, PubMed, Cochrane Library, and Medline database for relevant articles on all types of wound debridement. Articles included were all systematic review on the effectiveness of wound debridement-related outcome, published within the year 2017 until Aug 2021, in English.

Results

A total of seven scientific articles had been selected for review out of 318 screened. The authors reviewed a total of 318 titles and abstracts related to wound debridement effectiveness. Seven articles that were selected were narratively reviewed by two authors. The findings of the review were organized into autolytic, enzymatic, sharp, surgical, biological, and mechanical debridement methods and includes the advantages and disadvantages of each. The author further explored on the role of wound debridement according to wound bed preparation model. Articles were synthesized and organized based on the authors, year, total studies included in the systematic review, study range of year, total sample, debridement method, wound types, and findings.

Conclusion

Maggot debridement therapy showed a consistent finding in terms of effectiveness in debriding chronic wounds. The newer debridement method includes hydro-surgery, low-frequency ultrasonic and enzymatic collagenase debridement were getting more attention due to faster wound bed preparation and less painful. However, these newer method of debridements showed inconclusive findings and the patient safety was not clearly defined. A higher level of review is warranted in the future study.

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Maggot debridement therapy (MDT) showed a consistent positive effect in treating chronic wounds.

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New debridement methods that gaining more attention includes hydro-surgery, low-frequency ultrasonic and enzymatic collagenase debridement.

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Newer debridement method reported faster wound bed preparation and deemed to be less pain.

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Patient safety was not clearly defined in these newer debridement methods.

A molecular approach to maggot debridement therapy with Lucilia sericata and its excretions/secretions in wound healing

Chronic wounds caused by underlying physiological causes such as diabetic wounds, pressure ulcers, venous leg ulcers and infected wounds affect a significant portion of the population. In order to treat chronic wounds, a strong debridement, removal of necrotic tissue, elimination of infection and stimulation of granulation tissue are required. Maggot debridement therapy (MDT), which is an alternative treatment method based on history, has been used quite widely. MDT is an efficient, simple, cost-effective and reliable biosurgery method using mostly larvae of Lucilia sericata fly species. Larvae can both physically remove necrotic tissue from the wound site and stimulate wound healing by activating molecular processes in the wound area through the enzymes they secrete. The larvae can stimulate wound healing by activating molecular processes in the wound area through enzymes in their excretions/secretions (ES). Studies have shown that ES has antibacterial, antifungal, anti-inflammatory, angiogenic, proliferative, hemostatic and tissue-regenerating effects both in vivo and in vitro. It is suggested that these effects stimulate wound healing and accelerate wound healing by initiating a direct signal cascade with cells in the wound area. However, the enzymes and peptides in ES are mostly still undefined. Examining the molecular content of ES and the biological effects of these ingredients is quite important to illuminate the molecular mechanism underlying MDT. More importantly, ES has the potential to have positive effects on wound healing and to be used more as a therapeutic agent in the future, so it can be applied as an alternative to MDT in wound healing.

Revisiting the concept of entomotoxicology

Until now, the term entomotoxicology has only been used in medico-legal sciences. However, entomotoxicology as a whole has a much wider scope and forensic entomotoxicology is just one of its branches. Based on the literature a wider definition of the term is presented. Today, we can distinguish two major branches of entomotoxicology: 1) Forensic entomotoxicology, which uses the insects as evidence of the presence of xenobiotics in decomposing tissue during an investigation and 2) Environmental entomotoxicology, which uses the insects as bioindicators of environmental pollution in non-criminal circumstances. While forensic entomotoxicology is a relatively new discipline, research in environmental entomotoxicology began as far back as the 1920s. A review of the work in entomotoxicology from the last 6 years is presented, covering several interesting new trends. This article aims to redefine entomotoxicology, which should increase awareness to bring more collaborations and multidisciplinary between related scientific fields.

The maggot therapy supply chain: a review of the literature and practice

Maggot therapy (MT) is the clinical application of living fly larvae for the treatment of non-healing wounds and wounds that require debridement. This systematized and expanded literature review is the first study to investigate MT through the conceptual and disciplinary framework of supply chain management. The review of 491 selected academic papers was expanded to include the grey literature and online information resources to construct a first-pass theory of the medicinal maggot supply chain. It shows that the literature to date has focused on isolated discussions of echelon-specific issues such as diet improvement and sterilization protocols in the production echelon, and the relative effectiveness of medicinal maggot application methods in the treatment echelon. There is little knowledge in the public domain regarding the transport and distribution of medicinal maggots, but existing supply chains for vaccines, blood and pathology specimens may provide learning and supply chain integration opportunities. Maggot therapy knowledge across the treatment echelon is generally substantive but there is still insufficient knowledge regarding patients' and health care providers' attitudes toward the therapy, and their experiences of receiving and administering MT. Moreover, there is no research concerned with the humane disposal of medicinal flies during production and after treatment.

What is the optimal treatment time for larval therapy? A study on incubation time and tissue debridement by bagged maggots of the greenbottle fly, Lucilia sericata

The effective use of larvae of the greenbottle fly, Lucilia sericata, in wound debridement requires a working knowledge of how feeding changes over time. Using a laboratory assay and bagged larval dressings, the effect of incubation time on larval feeding rates and body mass was investigated for up to 120 hours at 32°C. The mass of tissue digested increased significantly in incremental 24-hour periods up to 72 hours, with no significant consumption occurring afterwards. Larval mass increased only up to 48 hours. A further test comparing the efficacy of a single 96-hour application of larvae against two consecutive 48-hour applications found that the mass of tissue digested in the latter was 14.3% higher than the former, a difference that was statistically significant. Current clinical guidance suggests a 4-day application period for bagged larvae. Based on these results, an incubation time of 72 hours (3 days) for bagged larvae would be the most effective at the study temperature. However, it is acknowledged that wound temperature can vary, whereby feeding rates would likely differ. In view of this, we conclude that a period of 3 to 4 days is optimum for the application of larvae, and current guidelines should be adhered to.