Larva therapy in wound management

Maggot Treatment of Necrotic Toe Developed After Traumatic Subtotal Amputation

Maggot debridement therapy (MDT) has been used for years in the treatment of chronic wounds and necrotic tissues. We report a case of subtotally amputated third toe that was treated with MDT after reattachment and developing complete necrosis. The necrotic toe was replaced with viable tissue and the wound healed completely after 2 weeks of MDT application. This case points out the regenerative effects of MDT besides its mechanical debridement effect on the necrotic tissue.

Therapeutic effects of Lucilia sericata larval excretion/secretion products on Leishmania major under in vitro and in vivo conditions

BACKGROUND

Leishmaniasis is a neglected infectious disease caused by protozoa of the genus Leishmania. The disease generally manifests as characteristic skin lesions which require lengthy treatment with antimonial drugs that are often associated with adverse side effects. Therefore, a number of studies have focused on natural compounds as promising drugs for its treatment. This study aimed to evaluate the effects of larval excretion/secretion products (ES) of Lucilia sericata in crude and fractionated forms on Leishmania major, by using in vitro and in vivo models.

METHODS

The in vitro experiments involved evaluation of ES on both promastigotes and macrophage-engulfed amastigotes, whereas the in vivo experiments included comparative treatments of skin lesions in L. major-infected mice with Eucerin-formulated ES and Glucantime.

RESULTS

The half maximal inhibitory concentrations of the crude ES, > 10-kDa ES fraction, < 10-kDa ES fraction, and Glucantime were 38.7 μg/ml, 47.6 μg/ml, 63.3 μg/ml, and 29.1 μg/ml, respectively. Significant differences were observed between percentage viabilities of promastigotes treated with the crude ES and its fractions compared with the negative control (P < 0.0001). The crude ES was more effective on amastigotes than the two ES fractions at 300 μg/ml. The macroscopic measurements revealed that the reduction of lesion size in mice treated with the crude ES followed quicker cascades of healing than that of mice treated with Glucantime and the ES fractions.

CONCLUSIONS

The present study showed that the larval ES of L. sericata in both crude and fractionated forms are effective for both intracellular and extracellular forms of L. major. Also, the ES exert both topical and systemic effects on mice experimentally infected with L. major.

Maggot debridement therapy to treat hard-to-heal diabetic foot ulcers: a single-centre study

OBJECTIVE

Maggot debridement therapy (MDT) has seen a resurgence in recent years in the treatment of hard-to-heal wounds, as a result of rising antibiotic resistance. The sterilised larvae of Lucilia cuprina have been used in MDT in Malaysia since 2003, with encouraging results for the treatment of hard-to-heal diabetic wounds. We report a case series of 30 patients selected from our clinic by convenient sampling with diabetic lower limb ulcers treated with MDT. The average age of patients receiving MDT was >50 years. Of the 30 patients in the study, nine were female and 21 were male. All patients had underlying diabetes, two patients had leg ulcers and 28 patients had diabetic foot ulcers. Sterilised Lucilia cuprina larvae were applied via a standard method of 10 maggots per square centimetre and dressed with sterile gauze. The study endpoint was defined as ≤5% coverage with slough or necrotic tissue following three successive applications of MDT. In this study, maximum debridement of wounds was achieved in 96.6% (29 patients) of our patients, with ≤5% coverage with slough or necrotic tissue, in addition to a reduction in wound-related pain, as assessed by a visual analogue scale. No adverse events were reported. The findings of this study support the use of MDT as a safe, efficacious, and cost-effective method of managing diabetic wounds.

Effectiveness of broad-spectrum antiseptics in production of disinfected maggots of Lucilia sericata for use in wound debridement therapy

The establishment of low-cost, effective, safe and practical methods is necessary to increase the use of larval therapy in wound care. Although studies on external disinfection of calliphorid eggs have been reported, many studies lack data on the effect of disinfection on egg viability and the microorganisms found before disinfection. Therefore, the main objective of this study was to compare three antiseptic solutions, that is, chlorhexidine (5%), Dakin's solution (0.5% NaOCl) and povidone-iodine (10%), in terms of their ability to disinfect Lucilia sericata eggs. Egg viability after disinfection and microorganisms present on the eggs and larvae before and after treatment were also examined. None of the antiseptics had a significant effect on egg viability. Disinfection of L. sericata eggs with 0.5% NaOCl was the best method, as sterility tests showed no contamination. Escherichia coli, Bacillus subtilis and Proteus mirabilis were present in all cultures isolated from the non-disinfected eggs and larvae, while Enterococcus faecium, Enterococcus faecalis, Morganella morganii, Corynebacterium spp. and Providencia stuartii were isolated from more than half of the same cultures. Sterility testing of medicinal maggots after disinfection is crucial to prevent secondary infections and achieve a positive therapeutic outcome.

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.

Efficacy of maggot debridement therapy on refractory leg ulcers of Behçet disease: an open-label study

BACKGROUND

Cutaneous ulcers of Behçet disease (BD) are rare but have high morbidity and resistance to conventional therapies. An important and essential aspect of ulcer management is debridement. Regarding maggot therapy (MT), excretions of the green bottle fly, Lucilia sericata, have been shown to have the ability to remove necrotic debris and promote healing.

AIM

To evaluate the efficacy of MT for cutaneous ulcers of BD.

METHODS

In this open-label trial, patients with BD with refractory leg ulcers suitable for MT were enrolled. Maggot application was performed until complete debridement was achieved, and all patients were followed up for 12 months afterwards to assess the total healing of ulcers.

RESULTS

In total, 24 patients with 32 ulcers were enrolled. Using MT, 91.6% of all ulcers were completely debrided. Mean time to debridement was 14.9 days and mean number of cycles required was 5.3. Mean ulcer size was decreased by 23% with treatment. Time to debridement was positively correlated with pretreatment ulcer size and ulcer duration (P = 0.01 and P < 0.01) but not with ulcer depth, comorbidities, smoking, age or sex (P > 0.05 for all). During follow-up, 79.1% of all ulcers healed completely. Mean time required for total healing was positively correlated with ulcer duration, pretreatment and post-treatment ulcer area, ulcer depth and mean time to total debridement (P < 0.03, P = 0.00, P = 0.04 and P < 0.01, respectively).

CONCLUSIONS

To our knowledge, the findings presented in this first and unique study may provide key answers about factors affecting success rate of MT in BD cutaneous ulcers.

Changing attitudes toward maggot debridement therapy in wound treatment: a review and discussion

Maggot debridement therapy is the real-time placement of maggots into a wound by health professionals for the treatment of diabetic ulcers or hard-to-heal wounds infected with antibiotic-resistant bacteria. Maggot debridement therapy shortens healing and disinfects wounds. This paper is a literature review of maggot debridement therapy in the clinical setting today and addresses the costs and benefits of this therapy. It includes recommendations to engage healthcare providers and increase awareness of this therapeutic treatment. A case study is presented on the use of maggot therapy for full debridement of a necrotic wound and clearing of a meticillin-resistant Staphylococcus aureus infection. There is also discussion on how to engage healthcare workers and reduce anxieties about the use of maggots as a treatment for hard-to-heal wounds. Education and awareness are the key factors in changing healthcare workers attitudes to maggot debridement therapy.

Histological and Immunohistochemical Study of Wounds in Sheep Skin in Maggot Therapy by Using Protophormia terraenovae (Diptera: Calliphoridae) Larvae

A study was performed to evaluate the implication of Protophormia terraenovae larvae as a surgical therapy for wounded skin. Three groups of sheep (n = 25) were considered based on larval doses. Groups 1 and 2 were artificially infested with low and high concentrations of L1 stage P. terraenovae, respectively, and group 0 served as a control. Skin biopsies were taken at 4 and 14 d postinfestation (D.P.If). A histopathological study was carried out to evaluate the lesions with a score, numbers of eosinophils and mast cells, and an immunohistochemical analysis of CD3, CD79α, and CD68 as T lymphocytes, B lymphosytes, and macrophages, respectively. The results indicated that higher larval doses led to faster regeneration by 14 D.P.If. Furthermore, the higher larval doses showed a high number of the CD68 marker and eosinophils and a low number of CD3 and CD79α markers and mast cells. In addition, the number of mast cells, T lymphocytes, and macrophage markers increased when the lesion progressed; however, a low number of immunolabeled CD79α cells and eosinophils were observed. The results indicate a possible positive effect of larvae in the healing of certain wounds.

Effective wound bed preparation using maggot debridement therapy for patients with critical limb ischaemia

OBJECTIVE

Patients with critical limb ischaemia (CLI) lack sufficient blood flow in to the limb, which leads to difficulties in the normal wound healing process. Therefore, maggot debridement therapy (MDT) has not generally been recommended for CLI patients. We evaluated the effectiveness of wound bed preparation by MDT in CLI patients who had undergone mid-foot amputation.

METHODS

Patients who underwent mid-foot amputation after angioplasty between April 2014 and October 2016 were retrospectively investigated by classifying them into an MDT group or a conventional treatment group. The primary outcome was defined as achievement of wound healing. Secondary outcomes were the proportions of amputation-free survival (AFS) and successful ambulatory improvement. Propensity scores were used to evaluate treatment outcomes based on five factors: ankle-brachial index, skin perfusion pressure of the foot, nutritional status, experience with dialysis and age.

RESULTS

A total of 39 patients (39 legs) were included, seven within the MDT group and 32 in the conventional treatment group. Clinical backgrounds of the two groups showed no significant differences except for higher albumin levels for the MDT group (3.5±0.4g/dl; p=0.014). The wound healing proportion was significantly higher in the MDT group (86%) than in the control group (38%) (p=0.035). At 6 months after amputation, no significant differences were found between the two groups for AFS (71% versus 47%; p=0.41) or ambulatory capability (43% versus 28%; p=0.65). This result was also similar to the propensity score adjustment analysis.

CONCLUSIONS

The efficacy of MDT with favourable wound bed preparation was shown in our CLI patients based on effective debridement and granulation formation by maggots, avoiding the loss of their heels. Wound-healing rates after MDT were higher for patients than for those receiving conventional treatment. MDT is considered a valid adjuvant treatment strategy for patients with CLI after revascularisation treatment is conducted. More favourable wound bed preparation and successful graft take were achieved in the MDT group, suggesting the effectiveness of MDT for wound healing in CLI patients.

Investigation of antimicrobial effects of treated Lucilia sericata larvae extract on bacteria

BACKGROUND AND OBJECTIVES

Larval therapy refers to the use of Lucilia sericata larvae on chronic wounds, which is a successful method of chronic wounds treatment. The secretions of these larvae contain antibacterial compounds and lead to death or inhibition of bacterial growth.

MATERIALS AND METHODS

In this study, we investigated the antibacterial effects of Lucilia sericata larvae secretions which were in sterilized and multi antibiotic-resistant bacteria-treated forms on Gram-positive Bacillus subtilis bacteria and Gram-negative Escherichia coli bacteria. In the following, we evaluated changes in gene expression of lucifensin and attacin during treatment with multi antibiotic-resistant bacteria. Investigation of the antibacterial effect was carried out using optical absorption and antibiotic disk diffusion in order to study the expression of the aforementioned genes.

RESULTS

The results of this study showed that E. coli-treated larvae were able to inhibit the growth of E. coli and secretions of B. subtilis-treated larvae and were also able to inhibit the growth of B. subtilis. Gene expression of antibacterial peptides in multi antibiotic-resistant bacteria-treated larvae was increased in comparison to non-treated larvae.

CONCLUSION

Due to the significant antibacterial potency of bacteria-treated larvae secretions, the secretions can be a suitable candidate as a drug against antibiotic resistant bacteria, but additional tests are required. Since the antimicrobial peptides of insects have not yet produced any resistance in human pathogenic bacteria, they can be considered as a promising strategy for dealing with resistant infections.

Maggot debridement therapy for a patient with critical limb ischaemia and severe cardiac dysfunction: possibility of limb salvage

Ischaemic skin ulcer occurred on the foot of a 73-year-old man who had a history of fulminant myocarditis with severe cardiac dysfunction. We attempted wound bed preparation by maggot debridement therapy and salvaged his limb. It can be one of the adjuvant treatment strategies for critical limb ischaemia.

National Athletic Trainers' Association Position Statement: Management of Acute Skin Trauma

OBJECTIVE

  To present recommendations for the cleansing, debridement, dressing, and monitoring of acute skin trauma in patients.

BACKGROUND

  Acute skin trauma is common during participation in athletic and recreational activities. Clinical decisions and intervention protocols after injury vary among athletic trainers and are often based on ritualistic practices. An understanding of cleansing, debridement, and dressing techniques; clinical features of infection and adverse reactions; and monitoring of acute skin trauma is critical for certified athletic trainers and other allied health and medical professionals to create a local wound environment that promotes healing and lessens the risk of complications.

RECOMMENDATIONS

  These guidelines are intended to provide the certified athletic trainer and others participating in athletic health care with specific knowledge about and recommendations for the management of acute skin trauma.

The effect of Lucilia sericata- and Sarconesiopsis magellanica-derived larval therapy on Leishmania panamensis

This study's main objective was to evaluate the action of larval therapy derived from Lucilia sericata and Sarconesiopsis magellanica (blowflies) regarding Leishmania panamensis using an in vivo model. Eighteen golden hamsters (Mesocricetus auratus) were used; they were divided into 6 groups. The first three groups consisted of 4 animals each; these, in turn, were internally distributed into subgroups consisting of 2 hamsters to be used separately in treatments derived from each blowfly species. Group 1 was used in treating leishmanial lesions with larval therapy (LT), whilst the other two groups were used for evaluating the used of larval excretions and secretions (ES) after the ulcers had formed (group 2) and before they appeared (group 3). The three remaining groups (4, 5 and 6), consisting of two animals, were used as controls in the experiments. Biopsies were taken for histopathological and molecular analysis before, during and after the treatments; biopsies and smears were taken for assessing parasite presence and bacterial co-infection. LT and larval ES proved effective in treating the ulcers caused by the parasite. There were no statistically significant differences between the blowfly species regarding the ulcer cicatrisation parameters. There were granulomas in samples taken from lesions at the end of the treatments. The antibacterial action of larval treatment regarding co-infection in lesions caused by the parasite was also verified. These results potentially validate effective LT treatment against cutaneous leishmaniasis aimed at using it with humans in the future.

Maggot Debridement Therapy in the Palliative Setting

Success rates of Maggot Debridement Therapy (MDT) differ, but range from 70% to 80%. In this article it is argued that wound closure is not always feasible and is not always the aim of the treatment. A patient is described in whom the intent of MDT was not wound closure, but infection removal, reduction of odor, and eventually prevention of a below knee amputation. This succeeded: the pain was diminished, the odor reduced, and the wound showed signs of healing. Still the patient died. In maggot literature, as with other wound treatments, outcome is recorded as closed or as failed. In our opinion, MDT has other indications besides wound closure.

Maggot Debridement Therapy for Chronic Wounds

This article presents a general overview of maggot debridement therapy, as used in the management of chronic infected wounds. Much has been written about this treatment method, both historically and in the past decade. Current clinical practice is discussed and clinical and laboratory research are reviewed, with attention to the inherent challenges of such research. The nature of microbial and fungal bio-film formation in chronic wounds is considered, although little is yet known of the extent and characterization of this phenomenon. The prospects for the future are addressed. These include the need for globally acceptable criteria for clinical outcomes and guidelines for “best practice,” together with the pressing need for appropriately structured randomized controlled studies.

Evaluation of conventional therapeutic methods versus maggot therapy in the evolution of healing of tegumental injuries in Wistar rats with and without diabetes mellitus

Larval therapy consists on the application of sterilized carrion flies larvae, reared in laboratory, on acute, chronic, and/or infected wounds in order to promote healing. Conventional methods for treating injuries include mechanical debridement or silver-based dressings; however, they are not always effective for wound healing. Larval therapy is a feasible and safe treatment for therapeutic application and, in many cases, the only and the most recommended alternative for difficult healing injuries. Thus, this study aimed to evaluate the competence of Cochliomyia macellaria F. (Diptera: Calliphoridae) as a suitable species for therapeutic application and evaluate time and effectiveness of the types of treatments most commonly used to treat integumental injuries. C. macellaria eggs were obtained from colonies established in laboratory and sterilized prior to application. Twenty-five larvae were applied for each centimeter squared of lesion. Lesions were induced in 24 Wistar rats; type 1 diabetes mellitus was induced in 12 of them. Animals were divided in four groups with three individuals each, being denominated: larval therapy, larval therapy associated with foam dressing with silver release, mechanical debridement with foam dressing silver and control group, without treatment. All treatments were applied once and held for 24 h. Medical application of larvae was found to be safe, as only dead tissue was removed, and efficient to accelerate healing process when compared to other treatments.

Adjunct methods of the standard diabetic foot ulceration therapy

The outcome of management of diabetic foot ulceration (DFU) is poor and insufficient. DFU therapy includes the standard management as debridement of the wound, revascularization procedures, off-loading of the ulcer and antibacterial actions, and supplementation of growth factors and cytokines, leading to stimulation of granulation, epidermization, and angiogenesis. The aim of the present review is to summarize the adjunct methods of the standard DFU therapy as hyperbaric oxygen therapy (HBOT), maggot therapy (MT), and platelet-rich plasma therapy (PRPT). The results of preclinical and clinical trials indicated that the methods may reduce time of therapy, short-term morbidity, and the risk of major amputation.

Maggot debridement therapy for peripheral arterial disease

INTRODUCTION

Maggots are potent debriding agents capable of removing necrotic tissue and slough; however, it is still unclear which wounds are most likely to benefit from maggot debridement therapy (MDT). Thus, we performed this retrospective review to gain insight into the patient and therapy characteristics influencing outcome.

PATIENTS AND METHODS

We reviewed patients with foot ulcers caused by critical limb ischemia, encountered during the period between June 2005 and May 2010. The treatment outcomes were defined as effective or ineffective.

RESULTS

There were 16 patients with 16 leg ulcers. The patients were 13 men and 3 women, with an average age of 67.2 years (range, 47-85 years). Ten (63%) of the 16 ulcers were treated effectively. According to univariate analyses, an ankle brachial pressure index (ABI) lower than 0.6 (p = 0.03) had a negative impact on the outcome of MDT; however, outcome was not influenced by gender, obesity, ischemic heart disease, diabetes mellitus, hemodialysis, smoking, or laboratory findings.

CONCLUSIONS

Some patient characteristics, such as gender, obesity, ischemic heart disease, diabetes mellitus, hemodialysis, and smoking, do not seem to contraindicate eligibility for MDT. However, a limb with an ABI lower than 0.6 is less likely to benefit. (English Translation of J Jpn Coll Angiol 2011; 51: 209-213.).

Lucilia sericata chymotrypsin disrupts protein adhesin-mediated staphylococcal biofilm formation

Staphylococcus aureus and Staphylococcus epidermidis biofilms cause chronic infections due to their ability to form biofilms. The excretions/secretions of Lucilia sericata larvae (maggots) have effective activity for debridement and disruption of bacterial biofilms. In this paper, we demonstrate how chymotrypsin derived from maggot excretions/secretions disrupts protein-dependent bacterial biofilm formation mechanisms.

Increasing the options for management of large and complex chronic wounds with a scalable, closed-system dressing for maggot therapy

As reconstructive specialists, burn surgeons are often involved in managing large wounds of various etiologies. Such wounds can pose a management challenge, especially if they are chronic or occur in the setting of critical illness or multiple medical comorbidities. Medical maggots are an effective, selective, and low-risk method for wound debridement. However, their use in large and geometrically complex wounds is limited by the lack of scalability in currently available dressings, which are appropriate for smaller wounds but become cumbersome and ineffective in larger ones. This report describes a novel dressing designed for application of maggot debridement therapy in large and complex wounds. The authors then discuss how use of this dressing may create new management strategies for such wounds by allowing maggots to mechanically debride big, infected wounds. They describe the construction of a maggot containment dressing based on modified components from a negative pressure wound therapy system and provide a case report highlighting its successful clinical use in a large contaminated chronic wound resulting from Fournier's gangrene. In the case described, the novel dressing provided scalability, containment of maggots, control of secretions, and ease of use. The dressing created an environment suitable for maggot survival and allowed effective debridement of a heavily contaminated groin wound. The novel dressing described is shown to function appropriately, allowing controlled use of maggots for effective debridement of large, irregular wounds. Facilitating the use of maggots in such wounds may broaden the algorithm for their management.

Maggot therapy in wound management in modern era and a review of published literature

Maggot therapy is an old remedy, which is being looked into with renewed interest. The use of medicinal maggots was approved by Food and Drug Administration (FDA) as a medical device in 2004. Maggot therapy appears to be efficacious, well tolerated, and cost-effective. Because American Medical Association (AMA) and Centers for Medicare and Medicaid (CMS) released reimbursement coding guidelines with regards to maggot therapy, there is a potential for a wider use of maggot therapy in United States in the near future. Several mechanisms of action suggested for maggots in debriding wounds are discussed. While maggot therapy demonstrated effectiveness in necrotic wounds, not all wound types respond well to maggot therapy. Future large, randomized, well-designed studies would help better delineate the place of maggot therapy among other options for wound care, and determine whether maggot therapy should be initiated earlier in the course of treatment, or continued to be used as a last resort.

Maggot debridement: an alternative method for debridement

Debridement is an essential component to promote healing in a problem wound. Several techniques are available including maggot debridement therapy (MDT).

OBJECTIVE

To describe the efficacy of MDT for treating problem wound especially diabetic foot ulcers.

METHODS

The topic is elucidated from different points of view: the mode of action, when to use, use in a practice, clinical results, and discussing the problem of creating evidence for the clinical effect.

RESULTS

Literature and own results demonstrate that MDT is a safe method with few side effects. Maggot debridement therapy is as good as or better than conventional often surgical debridement, is more selective than surgical debridement, decreases time to healing and stay of patients in the ward, and may decrease the risk of major amputations. However, the evidence of these effects of MDT on the highest level is presently lacking. A detailed description of how to use MDT in practice is provided including a visual demonstration in a video.

CONCLUSION

In spite of lacking clinical evidence, MDT clinical experience strongly suggests that this technique is effective and safe. It can be used for most types of problem wounds, but our indication is primarily diabetic foot ulcers, because of its selectivity for debriding necrotic dead tissue. It may be a valuable alternative surgical/sharp debridement.

[Evaluation of the cost of treating pressure ulcers in hospitalized patients using industrialized dressings]

This work evaluated wound dresses used in the Neurosurgery Department of Restauração Hospital: polyurethane, hydrogel and activated carbon wound dresses and hydrogel with alginate used for pressure ulcer care. This work aimed to identify a critical factor that increases demand and cost of wound dresses. The evaluation conducted at the Neurosurgery Department identified individuals at risk of pressure ulcer development. Sixty-two patients were evaluated and the prevalence of pressure ulcer was 22.6% according to the Braden scale. Comparative evaluation between patients that didn't receive preventive measures and others that received, showed that the average daily cost of hospitalization for the first group was 45% higher than the mean for the second group. The Wilcoxon-Mann-Withiney test compared the population at risk to develop pressure ulcer and population at low risk showing that the evaluation of Braden Scale scores between the groups presents statistically significant differences and confidence limits of 95%. Pressure ulcer is a key quality indicator in health services.It is possible to reduce costs and offer higher quality public health services by implementing a training program of nursing staff using a preventive measure protocol based on a test to evaluate risk as Braden Scale.

Control of the myiasis-producing fly, Lucilia sericata, with Egyptian essential oils

BACKGROUND

Myiasis caused by Lucilia sericata (Diptera: Calliphoridae) is widely distributed throughout the world and affects both humans and animals. In addition, L. sericata larvae and adults may play a role in spreading causal agents of mycobacterial infections. Therefore, it is important to establish new and safe alternative methods of controlling this blowfly.

METHODS

The insecticidal effectiveness of four commercially available essential oils [lettuce (Lactuca sativa), chamomile (Matricaria chamomilla), anise (Pimpinella anisum), rosemary (Rosmarinus officinalis)] against third larval instars of L. sericata was evaluated. The effects of sublethal concentrations of these oils on pupation rates, adult emergences, sex ratios, and morphological anomalies were also determined.

RESULTS

The oils were highly toxic to L. sericata larvae, with median lethal concentrations (LC(50) ) of 0.57%, 0.85%, 2.74%, and 6.77% for lettuce, chamomile, anise, and rosemary oils, respectively. Pupation rates were markedly decreased after treatment with 8% lettuce oil, and adult emergence was suppressed by 2% lettuce and chamomile oils. Morphological abnormalities were recorded after treatment with all tested oils, and lettuce was the major cause of deformation. There was a predominance of males over females (4 : 1) after treatment with lower concentrations of chamomile and rosemary; such a skew toward males would lead to a population decline.

CONCLUSIONS

The four tested oils are inexpensive and may represent new botanical insecticides for controlling blowflies.

Assessment of neuropathic pain in the community

The purpose of this paper is to provide the reader with evidence basedclinical guidance regarding assessing neuropathic pain. Persistent pain is a huge burden on health-care provision and the prevalence of persistent neuropathic pain is likely to increase owing to the ageing population. The provision of appropriate relieving interventions depends on accurate assessment. This paper sets out to provide the reader with simple neuropathic assessment tools that can be applied to community care. This will allow the community nurse to identify patients who have neuropathic pain and will therefore enable appropriate management.

Clinical research on the bio-debridement effect of maggot therapy for treatment of chronically infected lesions

OBJECTIVE

To evaluate the bio-debridement effect of maggot therapy for treating chronically infected lesions.

METHODS

A retrospective study was conducted of 25 patients with diabetic foot ulcers and 18 patients with pressure ulcers after spinal cord injury treated by maggot therapy or traditional dressing. Changes in the lesions were observed and bacterial cultures tested.

RESULTS

All ulcers healed completely. The times taken to achieve bacterial negativity, granulation and healing of lesions were all significantly shorter in the maggot therapy group than in the control group, both for diabetic foot ulcers (P < 0.05) and pressure ulcers (P < 0.05).

CONCLUSION

Maggot therapy is a safe and effective method for treating chronically infected lesions.

Maggot excretions/secretions induces human microvascular endothelial cell migration through AKT1

Maggot therapy is a simple and highly successful method for healing of infected and necrotic wounds. The increasing evidences indicate that Maggot excretions/secretions (ES) plays important roles in the wounds healing process. But the precise molecular mechanisms remain undefined. Herein, we investigated if ES induced cell migration during wound healing process using microvascular endothelial cells (HMEC-1) as model, and this effect was associated with the activation of AKT1 and ERK1/2. Wound healing and transwell migration assays were performed to study the effects of ES on HMEC-1 cell migration. Our data showed that ES significantly induced HMEC-1 cell migration in both wound healing and transwell assays, and time-dependently (P < 0.05) activated AKT1, but not ERK1/2. Moreover LY294002 (a PI3K inhibitor) partially attenuated (P < 0.05) ES-induced cell migration in wound healing assay while completely inhibited (P < 0.05) ES-induced AKT1 activation. These findings demonstrate that ES directly induces HMEC-1 cell migration and this event is partially mediated by the activation of AKT1.

Larval therapy as a palliative treatment for severe arteriosclerotic gangrene on the feet

Larval therapy (LT) is known to be a gentle and effective method for removing necrotic tissue and bacteria and reducing the accompanying unpleasant odour. Ischaemia has been considered a relative contraindication for LT. We report a patient with ischaemia treated with LT. Inguinal revascularization was performed on a 69-year-old man with critical limb ischaemia, diabetes mellitus, heart failure and end-stage renal disease. Areas of dry black malodorous gangrene remained on the distal areas of the feet after surgery and the patient's poor health did not allow any additional surgery. The patient was referred to the dermatology department for LT. Although patients are usually given this treatment as inpatients, the patient requested treatment at home. After the first LT, there was a marked reduction in odour. The gangrene needed repeated applications of larvae to remove the dead tissue. After eight treatments, the result was more positive than we had expected, with total lack of odour and initiation of healing. Larvae cannot penetrate eschar, thus free-range larvae were used because they can move beneath the hard necrotic tissue and dissolve it.

Wound care in the geriatric client

With our aging population, chronic diseases that compromise skin integrity such as diabetes, peripheral vascular disease (venous hypertension, arterial insufficiency) are becoming increasingly common. Skin breakdown with ulcer and chronic wound formation is a frequent consequence of these diseases. Types of ulcers include pressure ulcers, vascular ulcers (arterial and venous hypertension), and neuropathic ulcers. Treatment of these ulcers involves recognizing the four stages of healing: coagulation, inflammation, proliferation, and maturation. Chronic wounds are frequently stalled in the inflammatory stage. Moving past the inflammation stage requires considering the bacterial burden, necrotic tissue, and moisture balance of the wound being treated. Bacterial overgrowth or infection needs to be treated with topical or systemic agents. In most cases, necrotic tissue needs to be debrided and moisture balance needs to be addressed by wetting dry tissue and drying wet tissue. Special dressings have been developed to accomplish these tasks. They include films, hydrocolloids, hydrogel dressings, foams, hydrofibers, composite and alginate dressings.

Maggot debridement therapy of infected ulcers: patient and wound factors influencing outcome - a study on 101 patients with 117 wounds

INTRODUCTION

It has been known for centuries that maggots are potent debriding agents capable of removing necrotic tissue and slough. In January 2004, the US Food and Drug Administration decided to regulate maggot debridement therapy (MDT). As it is still not clear which wounds are likely or unlikely to benefit from MDT, we performed a prospective study to gain more insight in patient and wound characteristics influencing outcome.

PATIENTS AND METHODS

In the period between August 2002 and December 2005, patients with infected wounds with signs of gangrenous or necrotic tissue who seemed suited for MDT were enrolled in the present study. In total, 101 patients with 117 ulcers were treated. Most wounds were worst-case scenarios, in which maggot therapy was a treatment of last resort.

RESULTS

In total, 72 patients (71%) were classified as ASA III or IV. In total, 78 of 116 wounds (67%) had a successful outcome. These wounds healed completely (n = 60), healed almost completely (n = 12) or were clean at least (n = 6) at last follow-up. These results seem to be in line with those in the literature. All wounds with a traumatic origin (n = 24) healed completely. All wounds with septic arthritis (n = 13), however, failed to heal and led in half of these cases to a major amputation. According to a multivariate analysis, chronic limb ischaemia (odds ratio [OR], 7.5), the depth of the wound (OR, 14.0), and older age (>or= 60 years; OR, 7.3) negatively influenced outcome. Outcome was not influenced by gender, obesity, diabetes mellitus, smoking, ASA-classification, location of the wound, wound size or wound duration.

CONCLUSIONS

Some patient characteristics (i. e. gender, obesity, smoking behaviour, presence of diabetes mellitus and ASA-classification at presentation) and some wound characteristics (i. e. location of the wound, wound duration and size) do not seem to contra-indicate eligibility for MDT. However, older patients and patients with chronic limb ischaemia or deep wounds are less likely to benefit from MDT. Septic arthritis does not seem to be a good indication for MDT.

Surgical wound bed preparation of chronic and acute wounds

Our aging population has presented us with many new challenges. One such challenge is the need to manage an increase in wound-related problems effectively and efficiently. Over time, two parallel, yet divergent, management systems have developed. One strategy, used by medical specialists, uses a variety of dressings, topical enzymes, and local and systemic medications ultimately aimed at the promotion of healing by secondary intention or, in some cases, optimization of the wound for surgical reconstruction. In the second strategy, used by surgeons, early surgical intervention is used to prepare the wound for reconstruction in a timelier manner while promoting the healing process. This article reviews the development of these two distinct management systems and their areas of commonality and sets forth a new model to support the role of surgery in the treatment of problematic wounds.

Larval therapy from antiquity to the present day: mechanisms of action, clinical applications and future potential

When modern medicine fails, it is often useful to draw ideas from ancient treatments. The therapeutic use of fly larvae to debride necrotic tissue, also known as larval therapy, maggot debridement therapy or biosurgery, dates back to the beginnings of civilisation. Despite repeatedly falling out of favour largely because of patient intolerance to the treatment, the practice of larval therapy is increasing around the world because of its efficacy, safety and simplicity. Clinical indications for larval treatment are varied, but, in particular, are wounds infected with multidrug-resistant bacteria and the presence of significant co-morbidities precluding surgical intervention. The flies most often used in larval therapy are the facultative calliphorids, with the greenbottle blowfly (Lucilia sericata) being the most widely used species. This review summarises the fascinating and turbulent history of larval therapy from its origin to the present day, including mechanisms of action and evidence for its clinical applications. It also explores future research directions.

Infection following soft tissue injury: its role in wound healing

PURPOSE OF REVIEW

Wound infection has always been an unconquered problem temporarily improved with the discovery of antibiotics but now struggling with an epidemic of resistant organisms. Wound healing has become a popular sub-speciality for the doctor and allied health professional working in the laboratory or at the bedside. It is a field with many new journals and frequent congresses that publish elaborate proceedings. These have been examined for this review.

RECENT FINDINGS

Measurement of infection remains elusive. A clear difference between contamination and infection is difficult to delineate. In the era of the HIV/AIDS epidemic attention is drawn to host factors, which when attended to are as effective in suppressing infection as antisepsis. The bacterial capacity to put on a protective coat known as biofilm is a newly investigated system.

SUMMARY

Antisepsis and antibiotics continue to provide a wealth of studies and some new technology. The evidence base, as examined by Cochrane systematic reviews, suggests that our strategy for preventing and dealing with infection of wounds needs further refinement.