Novel low-cost thermotherapy for cutaneous leishmaniasis in Peru

Alternative Non-Drug Treatment Options of the Most Neglected Parasitic Disease Cutaneous Leishmaniasis: A Narrative Review

With more than 12 million cases worldwide, leishmaniasis is one of the top 10 neglected tropical diseases. According to the WHO, there are approximately 2 million new cases each year in foci in around 90 countries, of which 1.5 million are cutaneous leishmaniasis (CL). Cutaneous leishmaniasis (CL) is a complex cutaneous condition that is caused by a variety of Leishmania species, including L. (Leishmania) major, L. (L) tropica, L. (L) aethiopica, L. (L) mexicana, L. (Viannia) braziliensis, and L. (L) amazonensis. The disease imposes a significant burden on those who are affected since it typically results in disfiguring scars and extreme social stigma. There are no vaccines or preventive treatments available, and chemotherapeutic medications, including antimonials, amphotericin B, miltefosine, paromomycin, pentamidine, and antifungal medications, have a high price tag, a significant risk of developing drug resistance, and a variety of systemic toxicities. To work around these limitations, researchers are continuously looking for brand-new medications and other forms of therapy. To avoid toxicity with systemic medication use, high cure rates have been observed using local therapy techniques such as cryotherapy, photodynamic therapy, and thermotherapy, in addition to some forms of traditional therapies, including leech and cauterization therapies. These CL therapeutic strategies are emphasized and assessed in this review to help with the process of locating the appropriate species-specific medicines with fewer side effects, lower costs, and elevated cure rates.

Systems biology of autophagy in leishmanial infection and its diverse role in precision medicine

Autophagy is a contentious issue in leishmaniasis and is emerging as a promising therapeutic regimen. Published research on the impact of autophagic regulation on Leishmania survival is inconclusive, despite numerous pieces of evidence that Leishmania spp. triggers autophagy in a variety of cell types. The mechanistic approach is poorly understood in the Leishmania parasite as autophagy is significant in both Leishmania and the host. Herein, this review discusses the autophagy proteins that are being investigated as potential therapeutic targets, the connection between autophagy and lipid metabolism, and microRNAs that regulate autophagy and lipid metabolism. It also highlights the use of systems biology to develop novel autophagy-dependent therapeutics for leishmaniasis by utilizing artificial intelligence (AI), machine learning (ML), mathematical modeling, network analysis, and other computational methods. Additionally, we have shown many databases for autophagy and metabolism in Leishmania parasites that suggest potential therapeutic targets for intricate signaling in the autophagy system. In a nutshell, the detailed understanding of the dynamics of autophagy in conjunction with lipids and miRNAs unfolds larger dimensions for future research.

Treatment of Cutaneous Leishmaniasis and Insights into Species-Specific Responses: A Narrative Review

Cutaneous leishmaniasis (CL) is a complex skin infection that has imposed a heavy burden on many developing countries and is caused by more than 20 Leishmania species. This disease is predominantly associated with disfiguring scars and major social stigma upon infection. The severity of the disease seemingly depends on many factors including the species of parasite, the host, region of endemicity, socio-economic status and the accessibility to health facilities. Despite myriad studies that have been performed on current and novel therapies, the treatment outcomes of CL remain contentious, possibly because of the knowledge gaps that still exist. The differential responses to the current CL therapies have become a major drawback in disease control, and the dearth of information on critical analyses of outcomes of such studies is a hindrance to the overall understanding. On the basis of currently available literature on treatment outcomes, we discuss the most effective doses, drug susceptibilities/resistance and treatment failures of the Leishmania genus for both monotherapy and combination therapy. This review focuses on the available treatment modalities for CL caused by different Leishmania species, with insights into their species-specific efficacies, which would inform the selection of appropriate drugs for the treatment and control of leishmaniasis.

Heat therapy for cutaneous leishmaniasis: A literature Review

Cutaneous leishmaniasis (CL) is endemic in many parts of the world with a high economic and health impact. Despite many treatments that have been suggested for this zoonotic infection, there is still no definite therapy for CL. Meglumine antimony compounds are considered as a standard treatment for leishmaniasis, however, these medications have a relatively high side effect profile and not always effective. Physical modalities including cryotherapy, laser, and heat therapy have also been used for this purpose. As a source of heat therapy, different methods have been used including radiofrequency, ultrasound, infrared, exothermic crystallization thermotherapy, and microwave. We reviewed all of the articles in PubMed regarding the use of heat therapy for the treatment of CL up to January 2020. According to our literature review, heat therapy using different sources showed promising results for the treatment of CL that were comparable to meglumine antimony. In addition, heat therapy has very low side effect profiles that are localized to the treatment area suggesting this method as a safe procedure for CL therapy. This study is a brief review of the literature about the effect of heat therapy on the treatment of CL. Performing randomized clinical trials to compare different methods of heat therapy and to compare it with meglumine antimony compounds is recommended.

Therapeutic Response to Thermotherapy in Cutaneous Leishmaniasis Treatment Failures for Sodium Stibogluconate: A Randomized Controlled Proof of Principle Clinical Trial

Treatment failure to intralesional sodium stibogluconate (IL-SSG) is a health challenge for cutaneous leishmaniasis (CL) in Sri Lanka. A randomized controlled proof of principle clinical trial, with two arms (viz., radio frequency-induced heat therapy [RFHT] by a ThermoMed™ device and thermotherapy by a handheld exothermic crystallization thermotherapy for CL [HECT-CL] device) was conducted on 40 CL treatment failures to IL-SSG, from three hospitals in Tangalle, Hambantota, and Anuradhapura, from January 2017 to January 2018, followed up for 180 days post-thermotherapy with a final follow-up in February 2020. Intention-to-treat cure rates were calculated at day 90 (initial cure rate) and at day 180 (final cure rate) posttreatment. Radio frequency-induced heat therapy group: the initial cure rate was 100% (20/20) and the final cure rate was 95% (19/20), with one patient relapsing. The HECT-CL group: both the initial and final cure rates were 80% (16/20), with no relapses and one excluded from the trial. In February 2020 (1.6-3 years posttreatment), 27 traceable patients (RFHT = 16, HECT-CL = 11) remained healed. Second-degree burns were observed with RFHT in 65% (13/20), with HECT-CL in 15% (3/20), which completely resolved subsequently. The cure rates between the two treatment groups were comparable (P = 0.15). Radio frequency-induced heat therapy consumed less time and required only a single hospital visit. Handheld exothermic crystallization thermotherapy for CL is potentially usable at community settings with both being less costly than IL-SSG. This study is the first proof that thermotherapy is an efficacious and safe treatment for CL patients in Sri Lanka, complicated by treatment failure to IL-SSG.

Recent advances and new strategies on leishmaniasis treatment

Leishmaniasis is one of the most important tropical neglected diseases according to the World Health Organization. Even after more than a century, we still have few drugs for the disease therapy and their great toxicity and side effects put in check the treatment control program around the world. Moreover, the emergence of strains resistant to conventional drugs, co-infections such as HIV/Leishmania spp., the small therapeutic arsenal (pentavalent antimonials, amphotericin B and formulations, and miltefosine), and the low investment for the discovery/development of new drugs force researchers and world health agencies to seek new strategies to combat and control this important neglected disease. In this context, the aim of this review is to summarize new advances and new strategies used on leishmaniasis therapy addressing alternative and innovative treatment paths such as physical and local/topical therapies, combination or multi-drug uses, immunomodulation, drug repurposing, and the nanotechnology-based drug delivery systems.Key points• The treatment of leishmaniasis is a challenge for global health agencies.• Toxicity, side effects, reduced therapeutic arsenal, and drug resistance are the main problems.• New strategies and recent advances on leishmaniasis treatment are urgent.• Immunomodulators, nanotechnology, and drug repurposing are the future of leishmaniasis treatment.

Failure of an Innovative Low-Cost, Noninvasive Thermotherapy Device for Treating Cutaneous Leishmaniasis Caused by Leishmania tropica in Pakistan

Cutaneous leishmaniasis (CL), a neglected parasitic skin disease, is endemic in Pakistan, where Leishmania tropica and Leishmania major are the causative protozoan species. Standard treatment with antimonial injections is long, painful, and costly; has toxic side effects; and is not always available in public hospitals. Small pilot studies have previously evaluated a low-cost and noninvasive hand-held exothermic crystallization thermotherapy for cutaneous leishmaniasis (HECT-CL) device. We aimed to further establish the effectiveness, safety, and feasibility of HECT-CL in L. tropica. In a prospective observational study, patients with parasitological confirmation of CL were treated using the HECT-CL heat pack for 3 minutes with an initial temperature of 52–53°C for 7 consecutive days. Dried blood spot samples were taken for species identification by polymerase chain reaction (PCR). Effectiveness was assessed by using medical photographs and measurements of the lesion size at baseline and subsequent follow-up visits, for up to 180 days. We intended to enroll 317 patients. The HECT-CL treatment was easy to apply and well tolerated. Species identification demonstrated the presence of L. tropica. Interim analysis of 56 patients showed a failure rate of 91% at follow-up (median 45 days after treatment, interquartile range 30–60 days). Enrollment of patients was prematurely suspended because of futility. This study showed a high failure rate for HECT-CL thermotherapy in this setting. Leishmania tropica is known to be less sensitive to antileishmanial drugs, more temperature-resistant, and spontaneous healing is slower than that in L. major. More research is needed to identify low-cost, effective, and more patient-friendly treatment for L. tropica.

Leishmaniasis

Leishmaniasis is a poverty-related disease with two main clinical forms: visceral leishmaniasis and cutaneous leishmaniasis. An estimated 0·7-1 million new cases of leishmaniasis per year are reported from nearly 100 endemic countries. The number of reported visceral leishmaniasis cases has decreased substantially in the past decade as a result of better access to diagnosis and treatment and more intense vector control within an elimination initiative in Asia, although natural cycles in transmission intensity might play a role. In east Africa however, the case numbers of this fatal disease continue to be sustained. Increased conflict in endemic areas of cutaneous leishmaniasis and forced displacement has resulted in a surge in these endemic areas as well as clinics across the world. WHO lists leishmaniasis as one of the neglected tropical diseases for which the development of new treatments is a priority. Major evidence gaps remain, and new tools are needed before leishmaniasis can be definitively controlled.

The successful use of radiofrequency-induced heat therapy for cutaneous leishmaniasis: a review

The present gold standard of the treatment of cutaneous leishmaniasis (CL) is pentavalent antimonials either sodium stibogluconate (Pentostam) or meglumine antimoniate (Glucantime), These drugs are quite toxic. They are given by injection and usually administered intramuscularly or intravenously for three weeks or intralesionally for seven or more weeks. That is why the successful introduction of radiofrequency-induced heat therapy using a Thermomed™ 1.8 instrument administered in a single application, with minimal toxic effects, is so important for the treatment of CL.

Clinical features and treatment response of cutaneous leishmaniasis in North-West Ethiopia

OBJECTIVE

Cutaneous leishmaniasis (CL) receives far less attention than visceral leishmaniasis. Nevertheless, CL is predominantly caused by a unique species in Ethiopia (L. aethiopica), which is known to cause severe forms such as diffuse (DCL) and mucocutaneous leishmaniasis (MCL). We report on the number and type of CL cases diagnosed, the clinical features, the treatments and treatment outcomes in North-West Ethiopia.

METHODS

This is a retrospective chart record analysis of CL patients treated at the Leishmania Research and Treatment Center (LRTC) of the University of Gondar, Ethiopia.

RESULTS

From 178 CL patients seen between January 2014 and December 2015, a total of 154 chart records were retrieved. These included 80 localised CL (LCL), 7 DCL and 67 MCL. The median age was 23 years; 71.4% were male. Most (n = 121, 78.6%) of the lesions were on the face. The median time since onset was 12 months (6-24 months), and 28.6% presented after a trial of traditional medicine. The treatment of all forms of CL mainly consisted of 30 days of IM antimonial injections. Of these, 51/133 (38.3%) required treatment extension or change due to nonresponse. Three cases were treated with liposomal amphotericin B or miltefosine (two received the combination), of which two responded well.

CONCLUSION

CL was found to be complicated and difficult to treat. MCL was common, and patients presented after long delays. There is an urgent need to look for better treatment options for CL and improve access to care.

Treatment of Cutaneous Leishmaniasis Caused by Leishmania aethiopica: A Systematic Review

Leishmania aethiopica is the etiological agent of cutaneous leishmaniasis (CL) in Ethiopia and can cause severe and complicated cases such as diffuse CL (DCL), mucocutaneous leishmaniasis or extensive CL, requiring systemic treatment. Despite the substantial burden, evidence-based treatment guidelines are lacking. We conducted a systematic review of clinical studies reporting on treatment outcomes of CL due to L aethiopica in order to help identify potentially efficacious medications on CL that can be taken forward for clinical trials. We identified a total of 24 records reporting on 506 treatment episodes of CL presumably due to L aethiopica. The most commonly used drugs were antimonials (n = 201), pentamidine (n = 150) and cryotherapy (n = 103). There were 20 case reports/series, with an overall poor study quality. We only identified two small and/or poor quality randomized controlled trials conducted a long time ago. There were two prospective non-randomized studies reporting on cryotherapy, antimonials and pentamidine. With cryotherapy, cure rates were 60-80%, and 69-85% with antimonials. Pentamidine appeared effective against complicated CL, also in cases non-responsive to antimonials. However, all studies suffered from methodological limitations. Data on miltefosine, paromomycin and liposomal amphotericin B are extremely scarce. Only a few studies are available on DCL. The only potentially effective treatment options for DCL seem to be antimonials with paromomycin in combination or pentamidine, but none have been properly evaluated. In conclusion, the evidence-base for treatment of complicated CL due to L aethiopica is extremely limited. While antimonials remain the most available CL treatment in Ethiopia, their efficacy and safety in CL should be better defined. Most importantly, alternative first line treatments (such as miltefosine or paromomycin) should be explored. High quality trials on CL due to L aethiopica are urgently needed, exploring group sequential methods to evaluate several options in parallel.

Local Heat Application for the Treatment of Buruli Ulcer: Results of a Phase II Open Label Single Center Non Comparative Clinical Trial

Buruli ulcer (BU) is a necrotizing skin disease. Local thermotherapy is a highly effective, simple, cheap and safe treatment. It has in particular potential as home-based remedy for BU suspicious lesions at community level where laboratory confirmation is not available.

Background. Buruli ulcer (BU) is a necrotizing skin disease most prevalent among West African children. The causative organism, Mycobacterium ulcerans, is sensitive to temperatures above 37°C. We investigated the safety and efficacy of a local heat application device based on phase change material.

Methods. In a phase II open label single center noncomparative clinical trial (ISRCTN 72102977) under GCP standards in Cameroon, laboratory confirmed BU patients received up to 8 weeks of heat treatment. We assessed efficacy based on the endpoints ‘absence of clinical BU specific features’ or ‘wound closure’ within 6 months (“primary cure”), and ‘absence of clinical recurrence within 24 month’ (“definite cure”).

Results. Of 53 patients 51 (96%) had ulcerative disease. 62% were classified as World Health Organization category II, 19% each as category I and III. The average lesion size was 45 cm². Within 6 months after completion of heat treatment 92.4% (49 of 53, 95% confidence interval [CI], 81.8% to 98.0%) achieved cure of their primary lesion. At 24 months follow-up 83.7% (41 of 49, 95% CI, 70.3% to 92.7%) of patients with primary cure remained free of recurrence. Heat treatment was well tolerated; adverse effects were occasional mild local skin reactions.

Conclusions. Local thermotherapy is a highly effective, simple, cheap and safe treatment for M. ulcerans disease. It has in particular potential as home-based remedy for BU suspicious lesions at community level where laboratory confirmation is not available.

Clinical Trials Registration. ISRCT 72102977.

Cutaneous leishmaniasis in travellers: a focus on epidemiology and treatment in 2015

Imported cutaneous leishmaniasis (CL) is a growing problem with increasing global travel to endemic areas. Returned travellers seeking care encounter significant barriers to treatment, including diagnostic delays and difficult access to anti-leishmanial drugs. Treatment recommendations in non-endemic settings are a moving target, reflecting recent developments in Leishmania diagnostics and therapeutics. Accumulating experience with molecular-based species identification has enabled species-directed therapy. Clinicians are reevaluating more toxic traditional regimens in light of newly approved therapeutic agents and emerging data on local cutaneous treatments. Referral centers are implementing treatment decision algorithms designed to maximize efficacy while minimizing adverse events. Although management strategies continue to evolve, treatment of CL in non-endemic settings remains controversial. Persistent reliance on expert opinion reflects lack of research focused on travellers and limited randomized controlled trial evidence. We herein review the current epidemiology of cutaneous leishmaniasis in travellers and species-specific evidence for available therapies.

An update on pharmacotherapy for leishmaniasis

INTRODUCTION

Leishmaniasis broadly manifests as visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis. The treatment of leishmaniasis is challenging and the armamentarium of drugs is small, duration of treatment is long, and most drugs are toxic.

AREAS COVERED

A literature search on treatment of leishmaniasis was done on PubMed. Single dose of liposomal amphotericin B (L-AmB) and multidrug therapy (L-AmB + miltefosine, L-AmB + paromomycin (PM), or miltefosine + PM) are the treatment of choice for VL in the Indian subcontinent. A 17-day combination therapy of pentavalent antimonials (Sb(v)) and PM remains the treatment of choice for East African VL. L-AmB at a total dose of 18 - 21 mg/kg is the recommended regimen for VL in the Mediterranean region and South America. Treatment of CL should be decided by the severity of clinical lesions, etiological species and its potential to develop into mucosal leishmaniasis.

EXPERT OPINION

There is an urgent need to implement a single-dose L-AmB or combination therapy in the Indian subcontinent. Shorter and more acceptable regimens are needed for the treatment of post - kala-azar dermal leishmaniasis. Combination therapy with newer drugs needs to be tested in Africa. Due to the toxicity of systemic therapy, a trend toward local treatment for New World CL is preferred in patients without risk of mucosal disease.