Topical treatment of American cutaneous leishmaniasis with paramomycin and methylbenzethonium chloride: a clinical study under field conditions in Ecuador

Self-application of aminoglycoside-based creams to treat cutaneous leishmaniasis in travelers

BACKGROUND

In endemic foci, the use of an aquaphilic cream containing paromomycin with/without gentamicin to treat cutaneous leishmaniasis (CL) is safe, painless and cures 78-82% of patients with New and Old World CL. Self-application in travelers requires evaluation.

METHODS

Travelers with 1-10 lesions of confirmed CL were prospectively treated with the paromomycin-gentamicin formulation (WR279396, 2012-2017, Group 1) and carefully follow up, or treated with a locally produced paromomycin-only cream (2018-2022, Group 2). The cream was applied once under supervision, then self-applied daily for 20-30 days. A cured lesion was defined as 100% re-epithelialization at day 42 without relapse at three months.

RESULTS

Medical features were similar in Group 1 (17 patients), and Group 2 (23 patients). Patients were infected with either Leishmania major, L. infantum, L. killicki, L. guyanensis, L. braziliensis, or L. naiffi. Intention-to-treat and per-protocol cure rates were 82% (95% confidence interval (CI) [64.23;100.00]) and 87% (95% CI [71,29;100.00]) in Group 1, and 69% (95% CI [50.76; 88.37]) and 76% (95% CI [57.97; 94.41]) in Group 2. In the pooled Group 1&2, 75% (95% CI [61.58;88.42]) (30/40) and 81% (95% CI [68,46;93.6]) (30/37) of patients were cured in intention-to-treat and per-protocol, respectively. There were no significant differences observed in the success rates between Old World and New World CL (83.3% vs. 60%, p = 0.14). Prospective observations in Group 1 showed that adverse events were mainly pruritus (24%) and pain (18%) on lesions (all mild or moderate). No mucosal involvement was observed in either group.

DISCUSSION

In this representative population of travelers who acquired CL either in the Old or New World, the 81% per-protocol cure rate of a self-applied aminoglycoside cream was similar to that observed in clinical trials.

Field-Deployable Treatments For Leishmaniasis: Intrinsic Challenges, Recent Developments and Next Steps

Leishmaniasis is a neglected tropical disease endemic primarily to low- and middle-income countries, for which there has been inadequate development of affordable, safe, and efficacious therapies. Clinical manifestations of leishmaniasis range from self-healing skin lesions to lethal visceral infection with chances of relapse. Although treatments are available, secondary effects limit their use outside the clinic and negatively impact the quality of life of patients in endemic areas. Other non-medicinal treatments, such as thermotherapies, are limited to use in patients with cutaneous leishmaniasis but not with visceral infection. Recent studies shed light to mechanisms through which Leishmania can persist by hiding in cellular safe havens, even after chemotherapies. This review focuses on exploring the cellular niches that Leishmania parasites may be leveraging to persist within the host. Also, the cellular, metabolic, and molecular implications of Leishmania infection and how those could be targeted for therapeutic purposes are discussed. Other therapies, such as those developed against cancer or for manipulation of the ferroptosis pathway, are proposed as possible treatments against leishmaniasis due to their mechanisms of action. In particular, treatments that target hematopoietic stem cells and monocytes, which have recently been found to be necessary components to sustain the infection and provide a safe niche for the parasites are discussed in this review as potential field-deployable treatments against leishmaniasis.

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.

Therapeutic advances in the topical treatment of cutaneous leishmaniasis: A review

Cutaneous leishmaniasis has been endemic since decades. Millions of cases are reported worldwide specially in developing and underdeveloped countries. There are 2 major types of cutaneous leishmaniasis based on the causating species found in different regions of the world. These include New and Old World cutaneous leishmaniasis, which are self-healing, but if not treated, these may cause severe scars and many other complications like mucosal involvement. The conventional gold standard treatment for both types is mainly intralesional or parenteral administration of antimonial. Lately, a great deal of research has been done on development of topical treatment based on single agent or combination therapy. This review summarizes the current state of literature regarding therapeutic outcome of topical treatment against cutaneous leishmaniasis caused by different species in different regions.

Evaluating the effect of oral clarithromycin on acute cutaneous leishmaniasis lesions compared with systemic glucantime

BACKGROUND AND AIM

It is widely accepted that the high prevalence of leishmaniasis, demands the search for a tolerable effective treatment with the least side effects. This study aimed to evaluate the effect of treatment with clarithromycin on regression of lesions.

MATERIALS AND METHODS

This study was performed on 20 patients with leishmaniasis referred to dermatology clinic in 2017-2018. They were divided into two groups of intervention (500 mg oral clarithromycin twice a day) and control (20 mg/kg/day systematic glucantime). Induration size of lesions was recorded.

RESULTS

We had 20 patients with acute cutaneous leishmaniasis (CL) with 45 lesions in the control group and 49 lesions in the intervention group. In the control group, the mean number of lesions was 3 ± 2.8 and 5 ± 4.3 in each person in the control and intervention group (p=.63). The mean size of the largest diameter of lesions' induration at the beginning of the treatment was 19.81 ± 13 and 15.47 ± 15.6 mm in control and intervention group (p=.3) which changed to 1.59 and 0 respectively in three months after the treatment (p=.001).

CONCLUSIONS

We concluded oral clarithromycin had therapeutic effects on acute CL similar to systematic glucantime and could be considered as a safe and effective treatment option.

Application of laser for treatment of cutaneous leishmaniasis: a review of literature

Cutaneous leishmaniasis (CL) is a major health problem in developing countries with high economic and health impact. Despite suggested treatment for CL, there is still no definite therapy for this infection, and many of these treatments are associated with serious local and systemic side effects. In the current paper, use of different laser types including continuous and fractional CO2, argon, PDL, erbium glass, and Nd:YAG have been reviewed. Based on our review, given the high reported efficacy and low side-effect profile, use of laser can be considered as a good alternative to standard treatment of cutaneous leishmaniasis (CL). Performing more studies using different types of lasers is recommended to evaluate the efficacy of this method for treatment of CL.

Leishmaniases in Ecuador: Comprehensive review and current status

This article reviews current knowledge about leishmaniases in Ecuador, proceeding from 1920, when the first human case was described, to the present, mainly focusing on the recent research events published. Regarding basic situations, it appears that 23 of Ecuador's 24 provinces have leishmaniasis-case reports. The disease is one of the mandatory notification infectious diseases in the country since 2005. All the 21,305 cases notified to the Ministry of Public Health, during the period from 2001 through 2014, were said to involve different clinical features of cutaneous leishmaniasis (CL) but not visceral (VL). Eight Leishmania species, L. (Viannia) guyanensis, L. (V.) panamensis, L. (V.) braziliensis, L. (Leishmania) mexicana, L. (L.) amazonensis, L. (L.) major-like, L. (V.) naiffiand L. (V.) lainsoni were characterized. The last two species were most recently reported from the Ecuadorian Amazon regions. Of the 73 Ecuadorian Lutzomyia species (43 man-biting species) recorded, only four, Lu. trapidoi, Lu. gomezi, Lu. ayacuchensis, and Lu. tortura were incriminated as vectors of the Leishmania parasites. Current knowledge on the reservoir hosts of Leishmania in Ecuador is extremely poor. Recently, in Ecuador different kinds of molecular techniques were developed for diagnosis and mass screening of the disease, employing various materials derived from patients and sand fly vectors. These are PCR-RFLP, colorimetric FTA-LAMP etc. Brief comments and recommendations were also given, for future research and control of leishmaniases in Ecuador.

Cutaneous and mucocutaneous leishmaniasis: Differential diagnosis, diagnosis, histopathology, and management

The diagnosis of leishmaniasis can be challenging because it mimics both infectious and malignant conditions. A misdiagnosis may lead to an unfavorable outcome. Using culture, histologic, and/or polymerase chain reaction study results, a diagnosis of leishmaniasis can be established and treatment initiated. Appropriate management requires an accurate diagnosis, which often includes identification of the specific etiologic species. Different endemic areas have varying sensitivities to the same medication, even within individual species. Species identification may be of practical value, because infections with select species have a substantial risk of visceral involvement. In addition, HIV and otherwise immunocompromised patients with leishmaniasis have a propensity for diffuse cutaneous leishmaniasis. For most New World Leishmania species, parenteral antimonial drugs remain the first line of therapy, while Old World species are easily treated with physical modalities. Historically, live organism vaccination has been used and is effective in preventing leishmaniasis, but results in an inoculation scar and an incubation period that may last for years. A more effective method of vaccination would be welcome.

Selective inhibitors of trypanosomal uridylyl transferase RET1 establish druggability of RNA post-transcriptional modifications

Non-coding RNAs are crucial regulators for a vast array of cellular processes and have been implicated in human disease. These biological processes represent a hitherto untapped resource in our fight against disease. In this work we identify small molecule inhibitors of a non-coding RNA uridylylation pathway. The TUTase family of enzymes is important for modulating non-coding RNA pathways in both human cancer and pathogen systems. We demonstrate that this new class of drug target can be accessed with traditional drug discovery techniques. Using the Trypanosoma brucei TUTase, RET1, we identify TUTase inhibitors and lay the groundwork for the use of this new target class as a therapeutic opportunity for the under-served disease area of African Trypanosomiasis. In a broader sense this work demonstrates the therapeutic potential for targeting RNA post-transcriptional modifications with small molecules in human disease.

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.

Efficacy of thermotherapy to treat cutaneous leishmaniasis: a meta-analysis of controlled clinical trials

Introduction

The efficacy of thermotherapy for the treatment of cutaneous leishmaniasis presents diverse results with low statistical power.

Objective

To evaluate the efficacy of thermotherapy to treat cutaneous leishmaniasis.

Methods

A meta-analysis of controlled clinical trials in 12 databases based on the implementation of a research protocol with inclusion and exclusion criteria and an assessment of methodological quality. The reproducibility and completeness were guaranteed in the information search and extraction. Heterogeneity, sensitivity and publication bias were assessed by graphical methods (Galbraith, L'Abblé, funnel plot, Egger plot, and influence plot) and analytical methods (DerSimonian-Laird, Begg and Egger). Random-effects forest plots were constructed, and a cumulative meta-analysis was performed.

Results

Eight studies were included with 622 patients who underwent thermotherapy, with an efficacy of 73.2% (95% confidence interval (CI) = 69.6-76.7%), and with 667 patients who underwent systemic treatment, with an efficacy of 70.6% (95% CI=67.1-74.1%). Heterogeneity between studies, good sensitivity for the combined measure, and no publication bias were observed. The relative risk for comparison of the efficacy of treatment was 1.02 (95%CI=0.91, 1.15), showing that the effectiveness of thermotherapy is equal to that of pentavalent antimonial drugs.

Conclusion

Due to its efficacy, greater safety and lower cost, thermotherapy should be the first treatment option for cutaneous leishmaniasis in areas where the prevalence of the mucocutaneous form is low and in patients with contraindications to systemic treatment, such as kidney, liver and heart diseases, as well as in pregnant women, infants, and patients with human immunodeficiency virus infection/acquired immune deficiency syndrome.

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.

Therapeutic options for old world cutaneous leishmaniasis and new world cutaneous and mucocutaneous leishmaniasis

Estimated worldwide incidence of tegumentary leishmaniasis (cutaneous leishmaniasis [CL] and mucocutaneous leishmaniasis [MCL]) is over 1.5 million cases per year in 82 countries, with 90 % of cases occurring in Afghanistan, Brazil, Iran, Peru, Saudi Arabia and Syria. Current treatments of CL are poorly justified and have sub-optimal effectiveness. Treatment can be based on topical or systemic regimens. These different options must be based on Leishmania species, geographic regions, and clinical presentations. In certain cases of Old World CL (OWCL), lesions can spontaneously heal without any need for therapeutic intervention. Local therapies (thermotherapy, cryotherapy, paromomycin ointment, local infiltration with antimonials) are good options with less systemic toxicity, reserving systemic treatments (azole drugs, miltefosine, antimonials, amphotericin B formulations) mainly for complex cases. The majority of New World CL (NWCL) types require systemic treatment (mainly with pentavalent antimonials), either to speed the healing or to prevent dissemination to oral-nasal mucosa as MCL (NWMCL). These types of lesions are potentially serious and always require systemic-based regimens, mainly antimonials and pentamidine; however, the associated immunotherapy is promising. This paper is an exhaustive review of the published literature on the treatment of OWCL, NWCL and NWMCL, and provides treatment recommendations stratified according to their level of evidence regarding the species of Leishmania implicated and the geographical location of the infection.

LeishMan recommendations for treatment of cutaneous and mucosal leishmaniasis in travelers, 2014

BACKGROUND

Treatment of cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML) in travelers is still controversial. Over the last decade, national and international consortia have published recommendations for treating CL in travelers. These guidelines harmonize many issues, but there are some discrepancies.

METHODS

Leishmania parasites causing CL can now be genotyped by polymerase chain reaction techniques for detecting Leishmania DNA. Therefore, treatment recommendations can now be species based rather than based on geographical exposure. To review the evidence on which the recommendations were based, "LeishMan" (Leishmaniasis Management), a group of experts from 13 institutions in eight European countries, performed a PubMed MEDLINE) literature search and considered unpublished evidence and the experts' own personal experiences. The Oxford evidence grading system was used to evaluate the information.

RESULTS AND CONCLUSION

In this article, the authors provide practical treatment recommendations for imported CL and ML in Europe, drawn up from the review by the European experts.

Local or systemic treatment for New World cutaneous leishmaniasis? Re-evaluating the evidence for the risk of mucosal leishmaniasis

This review addresses the question of whether the risk of developing mucosal leishmaniasis (ML) warrants systemic treatment in all patients with New World cutaneous leishmaniasis (CL) or whether local treatment might be an acceptable alternative. The risk of patients with New World CL developing ML after the initial infection has been the main argument for systemic treatment. However, this statement needs re-evaluation and consideration of all the available data. The putative benefit of preventing ML should outweigh the toxicity of systemic antileishmanial therapy. To assess the need for and risk of systemic treatment the following factors were reviewed: the incidence and prevalence of ML in endemic populations and in travellers; the severity of mucosal lesions; the efficacy of current options to treat ML; the toxicity and, to a lesser extent, the costs of systemic treatment; the risk of developing ML after local treatment; and the strengths and limitations of current estimates of the risk of developing ML in different situations. Local treatment might be considered as a valuable treatment option for travellers suffering from New World CL, provided that there are no risk factors for developing ML such as multiple lesions, big lesions (>4 cm(2)), localisation of the lesion on the head or neck, immunosuppression or acquisition of infection in the high Andean countries, notably Bolivia.

Efficacy of paromomycin ointment in the treatment of cutaneous leishmaniasis: results of a double-blind, randomized trial in Isfahan, Iran

Although pentavalent antimonials are often used in the first-line treatment of cutaneous leishmaniasis (CL), they have several adverse effects. Intralesional administration of antimonials and other antileishmanial drugs can be painful. In the present, double-blind, randomized study, to determine if topical treatment with paromomycin is effective in the treatment of CL, 35 cases of CL were treated, twice daily for 30 days, with a commercial skin-care lotion containing 10% urea (the placebo) and another 30 were similarly treated with the same lotion to which paromomycin sulphate had been added (to give a concentration of 15%). Each case was assessed clinically 7, 14, 21 and 30 days after treatment began, and parasitologically 30 and 60 days after the initiation of treatment. Five (17%) and five (17%) of the cases treated with paromomycin showed complete healing, with the apparent clearance of amastigotes from their lesions, 30 and 60 days after treatment began, respectively. At the same time-points, however, the lesions on six (17%) and seven (20%) of the cases in the placebo group, respectively, also appeared to have healed completely. Ointment containing 15% paromomycin therefore appears ineffective in the treatment of CL, at least when applied twice daily for 30 days to the lesions of cases from an endemic area of Isfahan, Iran.

Development of liposomes loaded with anti-leishmanial drugs for the treatment of cutaneous leishmaniasis

Cutaneous leishmaniasis is caused by different species of Leishmania parasites and its available treatments have not yet provided a strong consistent result. The weak response of current chemotherapeutics is due to their deficient effects on stealth parasites inside macrophages, rapid clearance from the site of action and systemic side effects in high doses. Liposomal formulation of anti-leishmanial drugs could overcome these problems. In this study, different liposomal formulations of three famous anti-leishmanial drugs: Glucantime®, miltefosine and paromomycin were prepared by a modified freeze-drying double emulsion method. Liposome size, zeta potential and encapsulation efficiency were evaluated, and their imaging was carried out by means of atomic force microscopy. Three formulations were evaluated in vivo by subcutaneous injection into skin lesions caused by Leishmania major in BALB/c mice. Encapsulation efficiency of prepared liposomes was up to 90%; however, they inherited a bimodal size distribution that caused their encapsulation efficiency to decrease to 50% during filtering sterilization. Besides, the effect of surface charge was significant on preparation procedure, size and encapsulation efficiency. All three formulations reduced amastigote counts and lesion size but only miltefosine-loaded formulations had significant therapeutic effects compared with control group (p < 0.05).

Leishmaniasis: an update of current pharmacotherapy

INTRODUCTION

Leishmaniasis broadly manifests as visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL). The treatment of VL is challenging. The duration of treatment is long, and drugs are toxic thereby needing monitoring and hospitalization.

AREAS COVERED

Novel therapies such as single dose of liposomal amphotericin B (L-AmB) and multidrug therapy are important breakthrough for VL in the Indian subcontinent and have been recommended as the treatment of choice in this region. African Leishmania donovani is less susceptible to L-AmB, miltefosine and paromomycin as compared to the Indian strains, and the treatment of choice remains a 17-day combination therapy of pentavalent antimonials (SB(v)) and paromomycin. L-AmB at a total dose of 18 - 21 mg/kg is the recommended regimen in the Mediterranean region and South America. It is also the treatment of choice for HIV-VL coinfection. Treatment of CL should be decided by the clinical lesions, etiological species and its potential to develop into mucosal leishmaniasis. A literature search on treatment of leishmaniasis was done on PubMed and through Google.

EXPERT OPINION

There is an urgent need for exploratory studies with short course, highly efficient regimens such as single dose L-AmB or combination therapy for all the endemic regions of VL. Shorter and more acceptable regimens are needed for the treatment of post-kala-azar dermal leishmaniasis. Treatment of CL remains one of the neglected areas of leishmaniasis as data are scarce and drawn from uncontrolled studies.

Treatment strategies for mucocutaneous leishmaniasis

Mucocutaneous is an infection caused by a single celled parasite transmitted by sand fly bites. There are about 20 species of Leishmania that may cause mucocutaneous leishmaniasis. Some Leishmania species are closely linked to humans and are therefore found in cities (L. tropica) whereas some others are more traditionally associated with animal species and therefore considered zoonoses (L. major). The evidence for optimal treatment of mucocutaneous leishmaniasis is patchy. Although the cutaneous form of the disease is often self-limiting, it does result in significant scarring and can spread to more invasive, mucocutaneous disease. Therefore, treatment may be considered to prevent these complications. Drugs for systemic and topical treatment are presented and discussed with regard to their application, use and adverse effects.

Drug resistance in leishmaniasis

The treatment options of leishmaniasis are limited and far from satisfactory. For more than 60 years, treatment of leishmaniasis has centered around pentavalent antimonials (Sb^v). Widespread misuse has led to the emergence of Sb^v resistance in the hyperendemic areas of North Bihar. Other antileishmanials could also face the same fate, especially in the anthroponotic cycle. The HIV/ visceral leishmaniasis (VL) coinfected patients are another potential source for the emergence of drug resistance. At present no molecular markers of resistance are available and the only reliable method for monitoring resistance of isolates is the technically demanding in vitro amastigote-macrophage model. As the armametrium of drugs for leishmaniasis is limited, it is important that effective monitoring of drug use and response should be done to prevent the spread of resistance. Regimens of simultaneous or sequential combinations should be seriously considered to limit the emergence of resistance.

Current treatment for cutaneous leishmaniasis: a review

Cutaneous leishmaniasis is the most common form of leishmaniasis. It is a skin infection caused by a single-celled parasite that is transmitted by sand fly bites. There are about 20 species of Leishmania that may cause cutaneous leishmaniasis. Some Leishmania species are closely linked to humans and are therefore found in cities (Leishmania tropica), whereas some are more traditionally associated with animal species and are therefore considered zoonoses (Leishmania major). The evidence for optimal treatment of cutaneous leishmaniasis is patchy. Although the cutaneous form of the disease is often self-limiting, it does result in significant scarring and can spread to more invasive, mucocutaneous disease. Therefore, treatment may be considered to prevent these complications. Drugs for systemic and topical treatment are presented and discussed with regard to their application, use, and adverse effects.

WR279,396, a third generation aminoglycoside ointment for the treatment of Leishmania major cutaneous leishmaniasis: a phase 2, randomized, double blind, placebo controlled study

Background

Cutaneous leishmaniasis (CL) is a disfiguring disease that confronts clinicians with a quandary: leave patients untreated or engage in a complex or toxic treatment. Topical treatment of CL offers a practical and safe option. Accordingly, the treatment of CL with WR279,396, a formulation of paromomycin and gentamicin in a hydrophilic base, was investigated in a phase 2 clinical study in Tunisia and France.

Methods

A phase 2, randomized, double blind, vehicle-controlled study was conducted to assess the safety and efficacy of topical WR279,396 when applied twice a day for 20 days as treatment for parasitologically confirmed CL. The study protocol established the primary efficacy end point as complete clinical response (CCR) defined as 50% or greater reduction in the ulceration size of an index lesion by day 50 (D50) followed by complete re-epithelialization by D100, and no relapse through D180.

Results

Ninety-two subjects were randomized. Leishmania major was identified in 66 of 68 isolates typed (97%). In the intent-to-treat population, 47 of 50 WR279,396 treated participants (94%) met the definition of CCR, compared with 30 of 42 vehicle-placebo participants (71%) [p = 0.0045]. Erythema occurred in 30% and 24% of participants receiving WR279,396 and placebo, respectively [p = 0.64]. There was no clinical or laboratory evidence of systemic toxicity.

Conclusion

Application of WR279,396 for 20 days was found to be safe and effective in treating L. major CL, and offers great potential as a new, simple, easily applicable, and inexpensive topical therapy for this neglected disease.

Trial Registration

ClinicalTrials.gov NCT00703924

Cutaneous leishmaniasis is due to a small parasite (Leishmania) that creates disfiguring sores, and affects more than one million persons (mainly children) each year. Treating lesions with a cream—instead of with injections as currently done—would greatly improve the well-being of affected patients. No cream formulation that would be efficient and would not create important skin irritation has been identified yet. Here, we tested a new cream formulation (WR279,396) containing paromomycin and gentamicin, two members of a well-known family of antibacterial antibiotics (aminoglycosides). Injectable paromomycin is efficient in other forms of the disease (visceral leishmaniasis). This was a carefully monitored study (phase 2) involving mainly children in Tunisia and France. The cream was applied twice a day for 20 days. The proportion of patients treated with the paromomycin-containing cream (active formulation) that cured (94%) was higher than that observed (71%) in patients treated with a cream that did not contain the active product (placebo formulation). Local irritation affected less than one-third of the patients and was usually mild. This new cream formulation was safe and effective in treating cutaneous leishmaniasis, thereby providing a new, simple, easily applicable, and inexpensive treatment for this neglected disease.

Is paromomycin an effective and safe treatment against cutaneous leishmaniasis? A meta-analysis of 14 randomized controlled trials

Background

High cost, poor compliance, and systemic toxicity have limited the use of pentavalent antimony compounds (SbV), the treatment of choice for cutaneous leishmaniasis (CL). Paromomycin (PR) has been developed as an alternative to SbV, but existing data are conflicting.

Methodology/Principal Findings

We searched PubMed, Scopus, and Cochrane Central Register of Controlled Trials, without language restriction, through August 2007, to identify randomized controlled trials that compared the efficacy or safety between PR and placebo or SbV. Primary outcome was clinical cure, defined as complete healing, disappearance, or reepithelialization of all lesions. Data were extracted independently by two investigators, and pooled using a random-effects model. Fourteen trials including 1,221 patients were included. In placebo-controlled trials, topical PR appeared to have therapeutic activity against the old world and new world CL, with increased local reactions, when used with methylbenzethonium chloride (MBCL) compared to when used alone (risk ratio [RR] for clinical cure, 2.58 versus 1.01: RR for local reactions, 1.60 versus 1.07). In SbV-controlled trials, the efficacy of topical PR was not significantly different from that of intralesional SbV in the old world CL (RR, 0.70; 95% confidence interval, 0.26–1.89), whereas topical PR was inferior to parenteral SbV in treating the new world CL (0.67; 0.54–0.82). No significant difference in efficacy was found between parenteral PR and parenteral SbV in the new world CL (0.88; 0.56–1.38). Systemic side effects were fewer with topical or parenteral PR than parenteral SbV.

Conclusions/Significance

Topical PR with MBCL could be a therapeutic alternative to SbV in selected cases of the old world CL. Development of new formulations with better efficacy and tolerability remains to be an area of future research.

Millions of people worldwide are suffering from cutaneous leishmaniasis that is caused by parasites of the genus Leishmania. Although pentavalent antimony compounds are the treatment of choice, their use is limited by high cost, poor compliance, and systemic toxicity. Paromomycin was developed to overcome such limitations. However, there is no consensus on its efficacy. This meta-analysis assessed the efficacy and safety of paromomycin compared with placebo and pentavalent antimony compounds. Fourteen randomized controlled trials, including 1,221 patients, met our selection criteria. Topical paromomycin appeared to have therapeutic activity against the old world and new world cutaneous leishmaniasis, with increased local reactions, when combined with methylbenzethonium chloride. Topical paromomycin was not significantly different from intralesional pentavalent antimony compounds in treating the old world form, whereas it was inferior to parenteral pentavalent antimony compounds in treating the new world form. However, a similar efficacy was found between parenteral paromomycin and pentavalent antimony compounds in treating the new world form. Fewer systemic side effects were observed with topical and parenteral paromomycin than pentavalent antimony compounds. These results suggest that topical paromomycin with methylbenzethonium chloride could be a therapeutic alternative to pentavalent antimony compounds for selected cases of the old world cutaneous leishmaniasis.

Efeito de uma formulação hidrofílica de paromomicina tópica na leishmaniose cutânea em pacientes com contra-indicações de tratamento com antimonial pentavalente

Descrevem-se o efeito terapêutico e os eventos adversos associados com o uso tópico de paromomicina 10% em gel na leishmaniose cutânea. Quinze pacientes com leishmaniose cutânea cumpriram os critérios de inclusão descritos a seguir: contra-indicação para o uso de antimoniato de meglumina, intradermorreação de Montenegro positiva e até quatro lesões ulceradas. A fórmula foi prescrita duas vezes ao dia por 20 dias. Quatorze pacientes estiveram disponíveis para a avaliação do desfecho terapêutico e a proporção de cura foi de 21,4% (3/14), 50% melhoraram até a epitelização completa e a proporção de falha foi de 28,6%. Nove pacientes que não apresentaram cura inicialmente foram re-tratados. Oito receberam uma nova série de paromomicina tópica e um foi tratado com antimoniato de meglumina. Dois pacientes não receberam novo tratamento e tiveram melhora lenta e contínua. Cinco de oito pacientes retratados com paromomicina tópica alcançaram a cura clínica, e três apresentaram falha, incluindo um paciente que tinha apresentado melhora com o primeiro tratamento. Os eventos adversos foram leves e locais em 53,3% dos pacientes e nunca levaram à suspensão do tratamento.

Optimization of topical therapy for Leishmania major localized cutaneous leishmaniasis using a reliable C57BL/6 Model

Background

Because topical therapy is easy and usually painless, it is an attractive first-line option for the treatment of localized cutaneous leishmaniasis (LCL). Promising ointments are in the final stages of development. One main objective was to help optimize the treatment modalities of human LCL with WR279396, a topical formulation of aminoglycosides that was recently proven to be efficient and safe for use in humans.

Methodology/Principal Findings

C57BL/6 mice were inoculated in the ear with luciferase transgenic L. major and then treated with WR279396. The treatment period spanned lesion onset, and the evolution of clinical signs and bioluminescent parasite loads could be followed for several months without killing the mice. As judged by clinical healing and a 1.5-3 log parasite load decrease in less than 2 weeks, the 94% efficacy of 10 daily applications of WR279396 in mice was very similar to what had been previously observed in clinical trials. When WR279396 was applied with an occlusive dressing, parasitological and clinical efficacy was significantly increased and no rebound of parasite load was observed. In addition, 5 applications under occlusion were more efficient when done every other day for 10 days than daily for 5 days, showing that length of therapy is a more important determinant of treatment efficacy than the total dose topically applied.

Conclusions/Significance

Occlusion has a significant adjuvant effect on aminoglycoside ointment therapy of experimental cutaneaous leishmaniasis (CL), a concept that might apply to other antileishmanial or antimicrobial ointments. Generated in a laboratory mouse-based model that closely mimics the course of LCL in humans, our results support a schedule based on discontinuous applications for a few weeks rather than several daily applications for a few days.

When initiating the cutaneous disease named cutaneous leishmaniasis (CL), Leishmania parasites develop within the parasitophorous vacuoles of phagocytes residing in and/or recruited to the dermis, a process leading to more or less chronic dermis and epidermis-damaging inflammatory processes. Topical treatment of CL could be a mainstay in its management. Any improvements of topicals, such as new vehicles and shorter optimal contact regimes, could facilitate their use as an ambulatory treatment. Recently, WR279396, a third-generation aminoglycoside ointment, was designed with the aim to provide stability and optimal bioavailability for the molecules expected to target intracellular Leishmania. Two endpoints were expected to be reached: i) accelerated clearance of the maximal number of parasites, and ii) accelerated and stable repair processes without scars. A mouse model of CL was designed: it relies on the intradermal inoculation of luciferase-expressing Leishmania, allowing for in vivo bioluminescence imaging of the parasite load fluctuation, which can then be quantified simultaneously with the onset and resolution of clinical signs. These quantitative readout assays, deployed in real time, provide robust methods to rapidly assess efficacy of drugs/compounds i) to screen treatment modalities and ii) allow standardized comparison of different therapeutic agents.

Epidemiology of leishmaniasis in Ecuador: current status of knowledge -- a review

Although leishmaniasis is regarded as a significant health problem in Ecuador by the Ministry of Health, and the incidence has increased over the last years, an official map on the geographic distribution of disease and sand fly vectors or a control strategy do not exist yet. This article reviews the current situation based on published information to improve our knowledge and understand the epidemiological situation of leishmaniasis in Ecuador in order to help future research and to develop a national control strategy. The disease is endemic in most provinces throughout Pacific coastal region, Amazonian lowlands, and some inter-Andean valleys with a total 21,805 cases reported during 1990-2003. Whereas cutaneous leishmaniasis (CL) is found throughout Ecuador, mucocutaneous leishmaniasis (MCL) appears to be restricted to the Amazon region; one, parasitologically unconfirmed case of visceral form was reported in 1949. Most human infections are caused by Leishmania (Viannia) spp., which is distributed in the subtropical and tropical lowlands; infections due to L. (Leishmania) spp. are found in the Andean highlands and in the Pacific lowlands as well. The proven vectors are Lutzomyia trapidoi and Lu. ayacuchensis. Canis familiaris, Sciurus vulgaris, Potos flavus, and Tamandua tetradactyla have been found infected with Leishmania spp. It is estimated that around 3000-4500 people may be infected every year, and that 3.1 to 4.5 millions people are estimated to be at risk of contracting leishmaniasis.

Comparison of the effectiveness of two topical paromomycin treatments versus meglumine antimoniate for New World cutaneous leishmaniasis

The randomized, controlled study compared the therapeutic efficacy and safety of two paromomycin-containing topical preparations with the gold treatment standard, meglumine antimoniate, and with each other in 120 Ecuadorian patients with ulcerated lesions. The two paromomycin treatment comparisons were double-blinded. Group 1 (n = 14) received 15% paromomycin plus 12% methylbenzonium chloride (PR-MBCL) dissolved in a soft white paraffin base, applied twice daily for 30 days. Group 2 (n = 40) was also treated for 30 days with 15% paromomycin plus 10% urea (PR-U) dissolved in the same paraffin base. Group 3 (n = 40) received 20mg/kg/day of IM meglumine antimoniate (MA) for 10 days as per Ecuadorian Ministry of Public Health recommendations at the time of the study. The 10-day treatment was completed by 90% of the MA group compared to 72.5% of the PR-MBCL (X2 = 4.0, P = 0.045) and 75% of the PM-U (X2 = 3.1, P > 0.05) groups whose treatment regime lasted 20 days longer than the MA treatment. Post-treatment lesion burning, redness, inflammation, and soreness were more common in the two paromomycin groups compared to MA group (P < 0.05). The frequency of treatment-related side effects in the two paromomycin groups was similar. Six weeks after the start of treatment, 80.6% of MA subjects were clinically cured compared to 48.3% in the PR-MBCL (X2 = 6.1, P = 0.014) and 40% in the PM-U groups (X2 = 12.6, P = 0.002). By 12 weeks, the proportion of clinically cured subjects in the MA (91.7%) compared to PM-MBCL (79.3%) or PM-U (70%) groups was not significantly different (P > 0.05). MA-treated subjects clinically cured by 12 weeks had a faster mean healing time (29.5 +/- 12.2 days) compared to those in the PM-MBCL (versus 43.1 +/- 14.4 days, t = -3.7, P = 0.001) or PR-U groups (43.5 +/- 17 days; t = -3.2, P = 0.002). During the 48-week post-treatment follow-up period, infection reactivation was observed in 15.2% of the MA subjects compared to 17.4% in the PM-MBCL and 10.5% PM-U of subjects diagnosed as clinically healed by 12 weeks (P > 0.05). The results suggest that although the time required for the clinical healing of ulcerated lesions takes longer, topical paromomycin may be an acceptable therapeutic alternative in endemic areas where meglumine antimoniate is not available, is too costly or medically contraindicated.

[Therapy of tropical diseases after returning from travel]

Most tropical diseases imported by travelers can be treated quite effectively. Human endoparasites belong to the protozoa and worms. Protozoa can be seen as microparasites, characterized by short generation periods and high rates of reproduction within a host--consequently the diseases mainly are of short duration. Effective drugs are available for malaria, amebiasis and other intestinal protozoa as well as for leishmaniasis. Resistance, however, sometimes is a problem. Worms are macroparasites that generally do not reproduce within a host--teleologically speaking because otherwise they would rapidly damage their own basis of living. Accordingly, severe worm disease is rarely found in travelers. Levels of anthelminthic resistances so far are low. The most important worm disease in travelers is schistosomiasis, a disease that also can be treated effectively if diagnosed early.

Advances in the treatment of leishmaniasis

PURPOSE OF REVIEW

Treatment of leishmaniasis is far from satisfactory: all antileishmanial drugs are toxic and most have to be used parenterally for prolonged periods, especially for visceral leishmaniasis. In recent years, there has been a steady erosion in the efficacy of pentavalent antimony to cure visceral leishmaniasis in Bihar, India. In addition, several new antileishmanial formulations have become available.

RECENT FINDINGS

Through the publication of three studies from Africa, generic sodium stibogluconate, which is a fraction of the price of the branded drug Pentostam, has proven to be equivalent to Pentostam both in terms of safety and efficacy. The first oral drug, miltefosine, has been approved for treating visceral leishmaniasis in India, and preliminary reports of its efficacy against cutaneous leishmaniasis have been published. Interesting studies on successful low/single dose treatment of Indian visceral leishmaniasis with liposomal amphotericin B have been published. Several trials using different approaches towards treating cutaneous leishmaniasis are also reviewed. The results of clinical trials of two oral compounds are reported - fluconazole in treating cutaneous leishmaniasis was found to be safe and effective, whereas sitamaquine (WR6026) for visceral leishmaniasis was found to be toxic with poor efficacy.

SUMMARY

Generic stibogluconate enables the cost effective treatment of all forms of leishmaniasis as it remains the most important antileishmanial drug in most parts of the world. In India, successful single dose AmBisome for visceral leishmaniasis makes therapy simple and enables mass treatment, provided the drug cost is brought down. For cutaneous leishmaniasis, two new oral drugs, fluconazole and miltefosine, provide wider options to the clinician.

[Open therapeutic study with aminosidine sulfate in mucosal leishmaniasis caused by Leishmania (Viannia) braziliensis]

From September to November 1994. 21 patients with active mucosal leishmaniasis were treated with aminosidine sulphate 16 mg/kg/day by intramuscular injection for 20 days. They were principally adult male agricultural workers. Thirteen patients had not received specific treatment and eight had failed to respond to Glucantime therapy. Diagnosis was based on clinical and epidemiological observations, a search for the parasite, leishmanin skin sensitivity and indirect fluorescent antibody serological tests. Sixty seven percent of patients had leishmania parasites isolated from inoculated hamsters or visualized in imprints or histopathological sections. The mean follow-up period was 12.6 months. All patients completed treatment. Side effects were pain at the injection site (86%); mild proteinuria (24%), elevated serum creatinine (.5%) and subclinical bearing loss in one of two patients who did audiometric tests. Clinical cure was achieved in 48% and the accumulated relapse rate was 29% (4/14).

Tegumentary leishmaniasis in childhood

Very little has been published about tegumentary leishmaniasis in children and there are many controversies about this disorder in the literature. Therefore, we discuss the pathogenesis, clinical aspects, means to diagnosis, and treatment of this endemic disease.