Non-ulcerative cutaneous leishmaniasis in Honduras fails to respond to topical paromomycin

In Vivo Bioluminescence Imaging Reveals Differences in Leishmania infantum Parasite Killing Kinetics by Antileishmanial Reference Drugs

The bioluminescent Leishmania infantum BALB/c mouse model was used to evaluate the parasiticidal drug action kinetics of the reference drugs miltefosine, paromomycin, sodium stibogluconate, and liposomal amphotericin B. Infected mice were treated for 5 days starting from 7 days post-infection, and parasite burdens were monitored over time via bioluminescence imaging (BLI). Using nonlinear regression analyses of the BLI signal, the parasite elimination half-life (t1/2) in the liver, bone marrow, and whole body was determined and compared for the different treatment regimens. Significant differences in parasiticidal kinetics were recorded. A single intravenous dose of 0.5 mg/kg liposomal amphotericin B was the fastest acting with a t1/2 of less than 1 day. Intraperitoneal injection of paromomycin at 320 mg/kg for 5 days proved to be the slowest with a t1/2 of about 5 days in the liver and 16 days in the bone marrow. To conclude, evaluation of the cidal kinetics of the different antileishmanial reference drugs revealed striking differences in their parasite elimination half-lives. This BLI approach also enables an in-depth pharmacodynamic comparison between novel drug leads and may constitute an essential tool for the design of potential drug combinations.

Comparative assessment of interventions for treating cutaneous leishmaniasis: A network meta-analysis of randomized clinical trials

INTRODUCTION

Various interventions including laser therapy, heat therapy, and several drugs have been trialed in patients with cutaneous leishmaniasis. Due to the lack of an evidence-based comparison of all these interventions, we carried out the present network meta-analysis.

METHODS

Electronic databases were searched for randomized clinical trials evaluating the efficacy and safety of any interventions in patients with cutaneous leishmaniasis. The proportion of patients with complete cure was the primary outcome. The proportion of lesions cured at the end of treatment, the proportion of lesions with minimal/no response to treatment, and proportion of wounds with minimal/no change were the secondary outcomes. Random-effects modeling was used for generating pooled estimates. Rankogram plot was used for identifying the 'best intervention'. For interventions containing a combination of treatments, backslash (/) has been used for depicting the same.

RESULTS

One-hundred and thirty-one studies were included. Intralesional meglumine, topical paromomycin/gentamicin, topical paromomycin, parenteral sodium stibogluconate, topical honey/intralesional meglumine, topical liposomal amphotericin B, oral zinc sulphate, oral miltefosine, parenteral meglumine, heat therapy, topical liposomal azithromycin, intralesional meglumine/silver dressing, intralesional sodium stibogluconate, parenteral meglumine/intralesional meglumine, oral allopurinol/parenteral meglumine, topical trichloroacetic acid/heat therapy, oral zinc sulphate/oral ketoconazole, topical imiquimod/cryotherapy, intralesional meglumine/cryotherapy, topical herbal extract of Z-HE, parenteral pentamidine, topical trichloroacetic acid/intralesional meglumine, carbon-dioxide laser, topical recombinant granulocyte-macrophage colony-stimulating factor/parenteral meglumine, intralesional dapsone, carbon-dioxide laser/intralesional meglumine, moist wet dressing with sodium hypochlorite, parenteral sodium stibogluconate/intralesional recombinant granulocyte-macrophage colony-stimulating factor, oral dapsone, intralesional sodium stibogluconate/oral ketoconazole, intralesional sodium stibogluconate/parenteral sodium stibogluconate and electrocautery/moist wet dressing with sodium hypochlorite were observed with significantly greater proportion of patients with complete cure compared to placebo/untreated controls. Rankogram analysis revealed that parenteral pentamidine has the highest statistical probability of being the best in the pool.

CONCLUSION

We observed several interventions to be effective for treating cutaneous leishmaniasis. However, greater caution is required in interpreting the results as the estimates are likely to change with the advent of results from future studies.

Film-Forming Systems for the Delivery of DNDI-0690 to Treat Cutaneous Leishmaniasis

In cutaneous leishmaniasis (CL), parasites reside in the dermis, creating an opportunity for local drug administration potentially reducing adverse effects and improving treatment adherence compared to current therapies. Polymeric film-forming systems (FFSs) are directly applied to the skin and form a thin film as the solvent evaporates. In contrast to conventional topical dosage forms, FFSs strongly adhere to the skin, favouring sustained drug delivery to the affected site, reducing the need for frequent applications, and enhancing patient compliance. This study reports the first investigation of the use of film-forming systems for the delivery of DNDI-0690, a nitroimidazole compound with potent activity against CL-causing Leishmania species. A total of seven polymers with or without plasticiser were evaluated for drying time, stickiness, film-flexibility, and cosmetic attributes; three FFSs yielded a positive evaluation for all test parameters. The impact of each of these FFSs on the permeation of the model skin permeant hydrocortisone (hydrocortisone, 1% (w/v) across the Strat-M membrane was evaluated, and the formulations resulting in the highest and lowest permeation flux (Klucel LF with triethyl citrate and Eudragit RS with dibutyl sebacate, respectively) were selected as the FFS vehicle for DNDI-0690. The release and skin distribution of the drug upon application to Leishmania-infected and uninfected BALB/c mouse skin were examined using Franz diffusion cells followed by an evaluation of the efficacy of both DNDI-0690 FFSs (1% (w/v)) in an experimental CL model. Whereas the Eudragit film resulted in a higher permeation of DNDI-0690, the Klucel film was able to deposit four times more drug into the skin, where the parasite resides. Of the FFSs formulations, only the Eudragit system resulted in a reduced parasite load, but not reduced lesion size, when compared to the vehicle only control. Whereas drug delivery into the skin was successfully modulated using different FFS systems, the FFS systems selected were not effective for the topical application of DNDI-0690. The convenience and aesthetic of FFS systems alongside their ability to modulate drug delivery to and into the skin merit further investigation using other promising antileishmanial drugs.

Nanoemulsified Butenafine for Enhanced Performance against Experimental Cutaneous Leishmaniasis

The production of ergosterol lipid involves the activity of different enzymes and is a crucial event for the Leishmania membrane homeostasis. Such enzymes can be blocked by azoles and allylamines drugs, such as the antifungal butenafine chloride. This drug was active on parasites that cause cutaneous and visceral leishmaniasis. Based on the leishmanicidal activity of butenafine chloride and considering the absence of reports about the therapeutic potential of this drug in cutaneous leishmaniasis, the present work is aimed at analyzing the efficacy of butenafine formulated in two different topical delivery systems, the self-nanoemulsifying drug delivery systems (BUT-SNEDDS) and in a SNEDDS-based nanogel (BUT-SNEDDS gel) as well as in the free form in experimental cutaneous leishmaniasis. Physical studies showed that both formulations were below 300 nm with low polydispersity (<0.5) and good colloidal stability (around -25 mV). Increased steady-state flux was reported for nanoenabled butenafine formulations with reduced lag time in Franz cell diffusion assays across Strat-M membranes. No toxic or inflammatory reactions were detected in animals treated with BUT-SNEDDS, BUT-SNEDDS gel, or butenafine. Animals topically treated with butenafine (free or nanoformulated) showed small dermal lesions and low tissue parasitism. Furthermore, BUT-SNEDD gel and butenafine presented similar efficacy than the standard drug Glucantime given by the intralesional route. Increased levels of IFN-γ were observed in animals treated with BUT-SNEDDS gel or butenafine. Based on these data, the antifungal drug butenafine chloride can be considered an interesting repurposed drug for the treatment of cutaneous 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.

Interventions for American cutaneous and mucocutaneous leishmaniasis

BACKGROUND

On the American continent, cutaneous and mucocutaneous leishmaniasis (CL and MCL) are diseases associated with infection by several species of Leishmania parasites. Pentavalent antimonials remain the first-choice treatment. There are alternative interventions, but reviewing their effectiveness and safety is important as availability is limited. This is an update of a Cochrane Review first published in 2009.

OBJECTIVES

To assess the effects of interventions for all immuno-competent people who have American cutaneous and mucocutaneous leishmaniasis (ACML).

SEARCH METHODS

We updated our database searches of the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, LILACS and CINAHL to August 2019. We searched five trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing either single or combination treatments for ACML in immuno-competent people, diagnosed by clinical presentation and Leishmania infection confirmed by smear, culture, histology, or polymerase chain reaction on a biopsy specimen. The comparators were either no treatment, placebo only, or another active compound.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our key outcomes were the percentage of participants 'cured' at least three months after the end of treatment, adverse effects, and recurrence. We used GRADE to assess evidence certainty for each outcome.

MAIN RESULTS

We included 75 studies (37 were new), totalling 6533 randomised participants with ATL. The studies were mainly conducted in Central and South America at regional hospitals, local healthcare clinics, and research centres. More male participants were included (mean age: roughly 28.9 years (SD: 7.0)). The most common confirmed species were L. braziliensis, L. panamensis, and L. mexicana. The most assessed interventions and comparators were non-antimonial systemics (particularly oral miltefosine) and antimonials (particularly meglumine antimoniate (MA), which was also a common intervention), respectively. Three studies included moderate-to-severe cases of mucosal leishmaniasis but none included cases with diffuse cutaneous or disseminated CL, considered the severe cutaneous form. Lesions were mainly ulcerative and located in the extremities and limbs. The follow-up (FU) period ranged from 28 days to 7 years. All studies had high or unclear risk of bias in at least one domain (especially performance bias). None of the studies reported the degree of functional or aesthetic impairment, scarring, or quality of life. Compared to placebo, at one-year FU, intramuscular (IM) MA given for 20 days to treat L. braziliensis and L. panamensis infections in ACML may increase the likelihood of complete cure (risk ratio (RR) 4.23, 95% confidence interval (CI) 0.84 to 21.38; 2 RCTs, 157 participants; moderate-certainty evidence), but may also make little to no difference, since the 95% CI includes the possibility of both increased and reduced healing (cure rates), and IMMA probably increases severe adverse effects such as myalgias and arthralgias (RR 1.51, 95% CI 1.17 to 1.96; 1 RCT, 134 participants; moderate-certainty evidence). IMMA may make little to no difference to the recurrence risk, but the 95% CI includes the possibility of both increased and reduced risk (RR 1.79, 95% CI 0.17 to 19.26; 1 RCT, 127 participants; low-certainty evidence). Compared to placebo, at six-month FU, oral miltefosine given for 28 days to treat L. mexicana, L. panamensis and L. braziliensis infections in American cutaneous leishmaniasis (ACL) probably improves the likelihood of complete cure (RR 2.25, 95% CI 1.42 to 3.38), and probably increases nausea rates (RR 3.96, 95% CI 1.49 to 10.48) and vomiting (RR 6.92, 95% CI 2.68 to 17.86) (moderate-certainty evidence). Oral miltefosine may make little to no difference to the recurrence risk (RR 2.97, 95% CI 0.37 to 23.89; low-certainty evidence), but the 95% CI includes the possibility of both increased and reduced risk (all based on 1 RCT, 133 participants). Compared to IMMA, at 6 to 12 months FU, oral miltefosine given for 28 days to treat L. braziliensis, L. panamensis, L. guyanensis and L. amazonensis infections in ACML may make little to no difference to the likelihood of complete cure (RR 1.05, 95% CI 0.90 to 1.23; 7 RCTs, 676 participants; low-certainty evidence). Based on moderate-certainty evidence (3 RCTs, 464 participants), miltefosine probably increases nausea rates (RR 2.45, 95% CI 1.72 to 3.49) and vomiting (RR 4.76, 95% CI 1.82 to 12.46) compared to IMMA. Recurrence risk was not reported. For the rest of the key comparisons, recurrence risk was not reported, and risk of adverse events could not be estimated. Compared to IMMA, at 6 to 12 months FU, oral azithromycin given for 20 to 28 days to treat L. braziliensis infections in ACML probably reduces the likelihood of complete cure (RR 0.51, 95% CI 0.34 to 0.76; 2 RCTs, 93 participants; moderate-certainty evidence). Compared to intravenous MA (IVMA) and placebo, at 12 month FU, adding topical imiquimod to IVMA, given for 20 days to treat L. braziliensis, L. guyanensis and L. peruviana infections in ACL probably makes little to no difference to the likelihood of complete cure (RR 1.30, 95% CI 0.95 to 1.80; 1 RCT, 80 participants; moderate-certainty evidence). Compared to MA, at 6 months FU, one session of local thermotherapy to treat L. panamensis and L. braziliensis infections in ACL reduces the likelihood of complete cure (RR 0.80, 95% CI 0.68 to 0.95; 1 RCT, 292 participants; high-certainty evidence). Compared to IMMA and placebo, at 26 weeks FU, adding oral pentoxifylline to IMMA to treat CL (species not stated) probably makes little to no difference to the likelihood of complete cure (RR 0.86, 95% CI 0.63 to 1.18; 1 RCT, 70 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Evidence certainty was mostly moderate or low, due to methodological shortcomings, which precluded conclusive results. Overall, both IMMA and oral miltefosine probably result in an increase in cure rates, and nausea and vomiting are probably more common with miltefosine than with IMMA. Future trials should investigate interventions for mucosal leishmaniasis and evaluate recurrence rates of cutaneous leishmaniasis and its progression to mucosal disease.

Clinical and Immunological Features of Human Leishmania (L.) infantum-Infection, Novel Insights Honduras, Central America

Leishmania (Leishmania) infantum is the etiological agent of both American visceral leishmaniasis (AVL) and non-ulcerated cutaneous leishmaniasis (NUCL) in Honduras. Although AVL is the most severe clinical form of infection, recent studies have shown that human immune response to parasite infection can result in a clinical-immunological spectrum. The overall prevalence rate of infection and clinical-immunological profiles of the L. (L.) infantum infection in Amapala municipality, South Honduras was determined. We examined 576 individuals with diagnosis based on combined ELISA (IgG/IgM) and DTH assays. We also used genus-specific kDNA PCR and Hsp70 PCR-RFLP for NUCL cases. Clinical evaluation found 82% asymptomatic and 18% symptomatic individuals. All symptomatic cases (n = 104) showing NUCL were positive for parasites. We identified L. (L.) infantum species in 100% of the skin lesion scrapings and in 90% of the blood samples from NUCL cases studied. A total of 320 asymptomatic individuals were exposed (ELISA+ and/or DTH+), providing an overall L. (L.) infantum prevalence of 73.6%. Clinical, parasitological, and immunological evaluations suggest seven infection profiles, three asymptomatic and four symptomatic. This represents the first report on clinical and immunological features of human L. (L.) infantum-infection in Amapala municipality, Honduras.

Cutaneous Leishmaniasis Induces a Transmissible Dysbiotic Skin Microbiota that Promotes Skin Inflammation

Skin microbiota can impact allergic and autoimmune responses, wound healing, and anti-microbial defense. We investigated the role of skin microbiota in cutaneous leishmaniasis and found that human patients infected with Leishmania braziliensis develop dysbiotic skin microbiota, characterized by increases in the abundance of Staphylococcus and/or Streptococcus. Mice infected with L. major exhibit similar changes depending upon disease severity. Importantly, this dysbiosis is not limited to the lesion site, but is transmissible to normal skin distant from the infection site and to skin from co-housed naive mice. This observation allowed us to test whether a pre-existing dysbiotic skin microbiota influences disease, and we found that challenging dysbiotic naive mice with L. major or testing for contact hypersensitivity results in exacerbated skin inflammatory responses. These findings demonstrate that a dysbiotic skin microbiota is not only a consequence of tissue stress, but also enhances inflammation, which has implications for many inflammatory cutaneous diseases.

The Cure Rate after Placebo or No Therapy in American Cutaneous Leishmaniasis: A Systematic Review and Meta-Analysis

INTRODUCTION

There are few drugs with proven efficacy in cutaneous leishmaniasis (CL), and pentavalent antimonial derivatives are still the main first-line therapeutic agents worldwide, despite their recognized high toxicities. Randomized controlled clinical trials assessing the efficacy and safety of new therapeutic modalities are of high priority, and the definition of the design of such trials raises debate about the use of placebo as a comparator. To support the use of placebo as a comparator, two main points need to be addressed: 1--the cure rate without any therapeutic intervention and 2--the damage caused by CL and its impact on patients.

OBJECTIVE

The aim of this study was to systematically assess the spontaneous cure rate for American CL and to broaden the discussion about placebo use in CL trials.

METHODS

The PRISMA guidelines for systematic reviews and the Cochrane manual were followed. The sources used were the PubMed and LILACS databases. Studies were included if they reported cure rates using placebo or no treatment in American CL.

RESULTS

Thirteen studies of a total of 352 patients were ultimately included in this review. The summarized global cure rates for all Leishmania species according to the intention-to-treat analyses performed at approximately three ("initial cure") and nine ("definitive cure") months after "no treatment" or placebo use were 26% (CI95%: 16 to 40%) and 26% (CI95%:16 to 38%), respectively. Notably, a significantly lower cure rate was observed for L. braziliensis infection (6.4%, CI95%:0.2 to 20%) than for L. mexicana infection (44%, CI95%:19 to 72%), p = 0.002. Of note, relapse occurred in 20% of patients with initial healing (CI95%:9.2 to 38.9%).

CONCLUSION

These results clearly demonstrate a low spontaneous cure rate following no-treatment or placebo use, confirming that this strategy for the control group in CL studies expose patients to greater morbidity, especially for CL caused by L. braziliensis. Therefore, from this point, the crucial question to consider regarding placebo use is the seriousness of the suffering caused by this disease.

Topical Treatment Modalities for Old World Cutaneous Leishmaniasis: A Review

Diagnosis and therapy of cutaneous leishmaniasis (CL) can be difficult due to the variability of the clinical pictures and resistance to therapy. There is no vaccine currently available for CL. The aim of the present review is to describe different topical treatment modalities for old world CL. The mainstays of treatment for old world CL are pentavalent antimony compounds which are administered parenterally or intralesionally. New topical treatment alternatives have been available within the past few years. Amongst several treatments used topically, physical therapies including cryotherapy, heat therapy and CO2 laser are promising for the treatment of old world CL. Along with that, other randomized placebo controlled trials should be designed to find new effective therapeutic regimens.

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.

Interventions for American cutaneous and mucocutaneous leishmaniasis: a systematic review update

Introduction

Leishmaniasis is an important public health problem in the Americas. A Cochrane review published in 2009 analyzed 38 randomized controlled trials (RCT). We conducted a systematic review to evaluate the effects of therapeutic interventions for American cutaneous and mucocutaneous leishmaniasis.

Methods

All studies were extracted from PubMed, Embase, Lilacs (2009 to July, 2012 respectively), the Cochrane Central Register of Controlled Trials (6-2012) and references of identified publications. RCTs’ risk of bias was assessed.

Results

We identified 1865 references of interest; we finally included 10 new RCTs. The risk of bias scored low or unclear for most domains. Miltefosine was not significantly different from meglumine antimoniate in the complete cure rate at 6 months (4 RCT; 584 participants; ITT; RR: 1.12; 95%CI: 0.85 to 1.47; I2 78%). However a significant difference in the rate of complete cure favoring miltefosine at 6 months was found in L. panamensis and L. guyanensis (2 RCTs, 206 participants; ITT; RR: 1.22; 95%CI: 1.02 to 1.46; I2 0%). One RCT found that meglumine antimoniate was superior to pentamidine in the rate of complete cure for L. braziliensis (80 participants, ITT; RR: 2.21; 95%CI: 1.41 to 3.49), while another RCT assessing L. guyanensis did not find any significant difference. Although meta-analysis of three studies found a significant difference in the rate of complete cure at 3 months favoring imiquimod versus placebo (134 participants; ITT; RR: 1.45; 95%CI: 1.12 to 1.88; I2 0%), no significant differences were found at 6 and 12 months. Thermotherapy and nitric oxide were not superior to meglumine antimoniate.

Conclusion

Therapeutic interventions for American cutaneous and mucocutaneous leishmaniasis are varied and should be decided according to the context. Since mucosal disease is the more neglected form of leishmaniasis a multicentric trial should be urgently considered.

Polymerase chain reaction detection of Leishmania kDNA from the urine of Peruvian patients with cutaneous and mucocutaneous leishmaniasis

We hypothesized that Leishmania kDNA may be present in urine of patients with cutaneous leishmaniasis (CL). Urine samples and standard diagnostic specimens were collected from patients with skin lesions. kDNA polymerase chain reaction (PCR) was performed on samples from patients and 10 healthy volunteers from non-endemic areas. Eighty-six of 108 patients were diagnosed with CL and 18 (21%) had detectable Leishmania Viannia kDNA in the urine. Sensitivity and specificity were 20.9% (95% confidence interval [CI] 12.3-29.5%) and 100%. Six of 8 patients with mucocutaneous involvement had detectable kDNA in urine versus 12 of 78 patients with isolated cutaneous disease (P < 0.001). L. (V.) braziliensis (N = 3), L. (V.) guyanensis (N = 6), and L. (V.) peruviana (N = 3) were identified from urine. No healthy volunteer or patient with an alternate diagnosis had detectable kDNA in urine. Sensitivity of urine PCR is sub-optimal for diagnosis. On the basis of these preliminary data in a small number of patients, detectable kDNA in urine may identify less localized forms of infection and inform treatment decisions.

New World cutaneous leishmaniasis: updated review of current and future diagnosis and treatment

BACKGROUND

Cutaneous leishmaniasis (CL) has traditionally been underrecognized and underreported. Improved awareness is warranted as the number of cases has increased as a result of increased travel to endemic countries, the HIV/AIDS pandemic, and the larger number of military and contract workers deployed overseas.

OBJECTIVE

We sought to present a systematic review of evidence from a gamut of research trials on the treatment efficacy of different regimens and aggregate this knowledge for use as a guide for clinical practice decisions.

METHODS

We performed a comprehensive search of print and electronic sources to identify the accumulated research information on New World CL.

RESULTS

Topical treatment of New World CL lesions is generally not recommended. Findings support the systemic administration of pentavalent antimonials as first-line treatment. Exception to this is infection with L guyanensis in French Guiana where systemic pentamidine is suggested as first-line treatment.

LIMITATIONS

The reliability of the findings of this review of research evidence is dependent on the individual quality and potential bias in its component principal trials. There was a conscious attempt to only include evidence derived from randomized controlled studies, with adequate randomization, adequate patient numbers, and complete follow-up information. However, because of the relatively small number of such studies on New World CL, evidence from nonrandomized studies and case series studies was also considered.

CONCLUSIONS

The pentavalent antimony compounds remain the first-line treatment choice for the treatment of New World CL. Concerns with cost, availability, poor compliance, and systemic toxicity, however, may compel clinicians to opt for alternative treatment modalities. Some advances in the development of an antileishmanial vaccine have been made but none is yet available for clinic use. The increase, over recent years, in the incidence of CL warrants an enhanced effort to increase awareness of the disease, assure timely diagnosis, and implement effective management and treatment strategies.

Interventions for American cutaneous and mucocutaneous leishmaniasis

BACKGROUND

Pentavalent antimonial drugs are the most prescribed treatment for American cutaneous and mucocutaneous leishmaniasis. Other drugs have been used with varying success.

OBJECTIVES

To assess the effects of therapeutic interventions for American cutaneous and mucocutaneous leishmaniasis.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (January 2009), the Register of Controlled Clinical Trials in The Cochrane Library (Issue 1,2009), MEDLINE (2003 to January 2009), EMBASE (2005 to January 2009), LILACS (from inception to January 2009), CINAHL (1982-May 2007) and other databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) assessing treatments for American cutaneous and mucocutaneous leishmaniasis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included 38 trials involving 2728 participants. Results are based on individual studies or limited pooled analyses. There was good evidence in:Leishmania braziliensis and L. panamensis infections:Intramuscular (IM) meglumine antimoniate (MA) was better than oral allopurinol for 28 days (1RCT n=127, RR 0.39; 95% CI 0.26, 0.58). Intravenous (IV)MA for 20-days was better than 3-day and 7-day IVMA plus 15% paromomycin plus 12% methylbenzethonium chloride (PR-MBCL) or 7-day IVMA (1RCT n= 150, RR 0.24; 95% CI 0.11, 0.50; RR 0.69; 95% CI 0.53, 0.90; RR 0.64; 95% CI 0.44, 0.92 respectively). Oral allopurinol plus antimonials was better than IV antimonials (2RCT n= 168, RR 1.90; 95% CI 1.40, 2.59; I(2)=0%).L. braziliensis infections:Oral pentoxifylline plus IV sodium stibogluconate (SSG) was better than IVSSG (1RCT n= 23, RR 1.66; 95% CI 1.03, 2.69); IVMA was better than IM aminosidine sulphate (1RCT n= 38, RR 0.05; 95% CI 0.00, 0.78) and better than IV pentamidine isethionate (1RCT n= 80, RR 0.45; 95% CI 0.29, 0.71). Intramuscular MA was better than Bacillus Calmette-Guérin (1RCT n= 93, RR 0.46; 95% CI 0.32, 0.65).L .panamensis infections:Oral allopurinol was better than IVMA (1RCT n= 58, RR 2.20; 95% CI 1.34, 3.60). Aminosidine sulphate at doses of 12 mg/kg/day and 18 mg/kg/day for 14 days were better than aminosidine sulphate 12 mg/kg/day for 7 days (1RCT n= 60, RR 0.23; 95% CI 0.07, 0.73; RR 0.23; 95% CI 0.07, 0.73 respectively). Oral ketoconazole for 28 days, oral miltefosine and topical PR-MBCL were better than placebo.

AUTHORS' CONCLUSIONS

Most trials have been designed and reported so poorly that they are inconclusive. There is a need for large well conducted studies that evaluate long-term effects of current therapies to improve quality and standardization of methods.

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.

Paromomycin

Paromomycin is an aminoglycoside that is active against Gram-negative and many Gram-positive bacteria as well as some protozoa and cestodes. It is out of use as an antibiotic but was licensed in 2007 in India as an effective, well tolerated and affordable treatment for visceral leishmaniasis (VL) at a dose of 11 mg/kg (base) for 21 days. Currently, the non-profit group Drugs for Neglected Diseases Initiative is conducting studies on paromomycin (as monotherapy and in combination) in VL in Africa, and the Institute for OneWorld Health is conducting a Phase IV study in India. Paromomycin in combination with sodium stibogluconate has proven to be effective in African and Indian VL and improves survival in African VL. To prevent the emergence of drug-resistant leishmaniasis in areas of anthroponotic transmission (India and Africa), paromomycin should be used as part of combination therapy for VL. Further trials testing different combinations are much needed. In addition, the distribution of paromomycin (like other drugs for leishmaniasis) should be well regulated and preferably restricted to the public sector. These strategies should ensure the longevity of paromomycin as a useful drug for VL.

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.

Cutaneous leishmaniasis

Cutaneous leishmaniasis is endemic in the tropics and neotropics. It is often referred to as a group of diseases because of the varied spectrum of clinical manifestations, which range from small cutaneous nodules to gross mucosal tissue destruction. Cutaneous leishmaniasis can be caused by several Leishmania spp and is transmitted to human beings and animals by sandflies. Despite its increasing worldwide incidence, but because it is rarely fatal, cutaneous leishmaniasis has become one of the so-called neglected diseases, with little interest by financial donors, public-health authorities, and professionals to implement activities to research, prevent, or control the disease. In endemic countries, diagnosis is often made clinically and, if possible, by microscopic examination of lesion biopsy smears to visually confirm leishmania parasites as the cause. The use of more sophisticated diagnostic techniques that allow for species identification is usually restricted to research or clinical settings in non-endemic countries. The mainstays of cutaneous leishmaniasis treatment are pentavalent antimonials, with new oral and topical treatment alternatives only becoming available within the past few years; a vaccine currently does not exist. Disease prevention and control are difficult because of the complexity of cutaneous leishmaniasis epizoology, and the few options available for effective vector control.

Cutaneous leishmaniasis treatment

The causative species of cutaneous leishmaniasis determines the clinical features and courses, and treatments. Intralesional or systemic antimonials are the gold standard for the treatment of these diseases. However, as for visceral leishmaniasis, other therapeutic options appear promising. Paromomycin ointments are effective in Leishmania major, L. tropica, L. mexicana, and L. panamensis lesions. In L. braziliensis localized leishmaniasis, both paromomycin and imiquimod may be topically applied. Oral fluconazole and zinc sulfate are useful in L. major. Oral azithromycin, effective in vitro and in mice, needs further investigation in human leishmaniasis. On the contrary, data with oral itraconazole are disappointing. Oral miltefosine, which is very effective in visceral leishmaniasis caused by L. donovani, appears ineffective in L. major and L. braziliensis infections. Intramuscular pentamidine is required for L. guyanensis cutaneous leishmaniasis, for which systemic antimony is not effective. Liposomal amphotericin B could be an alternative to antimony in south American cutaneous leishmaniasis with mucosal involvement (especially L. braziliensis and L. guyanensis infections).

Identification of New WorldLeishmaniaspecies from Peru by biochemical techniques and multiplex PCR assay

We have characterized diverse strains or species of Leishmania isolated in humans that are currently circulating throughout Peru, by means of isoenzymatic characterization, kDNA analysis by restriction enzymes, and multiplex PCR assay. The cluster analysis gave five groups. Cluster 1 includes L. (L.) donovani together with the isolates LP4 and LP7, forming the donovani complex. Thus, this complex corresponds to the New World visceral form, L. (L.) chagasi. Cluster 2 is formed by the isolates LP1-LP3, LP6, LP10, LP9, and LP11, phylogenetically intermediate between Cluster 1 and Cluster 3, or they can be treated as hybrids. Cluster 3 is divided into two subgroups: one formed by L. (V.) peruviana, together with the isolates LP14 and LP5, and the second one formed by L. (V.) brazilensis and the isolate LP8. These two subgroups form part of the brazilensis complex. The three strains of L. (L.) infantum [L. (L.) infantum I and II and la LSI] make up Cluster 4. In Cluster 5, we include the three Mexican strains (LM1-LM3) forming one subgroup while we would place L. (L.) amazonensis in another subgroup. These two subgroups would comprise the complex mexicana.

Inorganic particles in the skin of inhabitants of volcanic areas of Central America: their possible immunomodulatory influence in leishmaniasis and leprosy

We have evaluated biopsies from patients with atypical nodular and typical ulcerated lesions of cutaneous leishmaniasis, from leishmanin reactions and skin from normal individuals from Nicaragua, Honduras and Guatemala for the presence of inorganic particles using confocal microscopy with a polarised light source and conventional histopathological techniques. Analysis by semiquantitative confocal microscopy permitted the demonstration of significantly larger numbers of particles in atypical lesions. Silica and aluminium, important components of these particles, were less abundant in particles from normal skin. The histology of these atypical lesions, characterised by 'naked' sarcoidal granulomas with epithelioid differentiation but very few lymphocytes, was very similar to the histological reaction observed after 14 days in persisting inflammation at leishmanin skin test sites. The presence of these unusual lesions in areas of Central American countries characterised by the presence of large amounts of volcanic ash, as well the unexpectedly low prevalence of leprosy in Central America, suggest that environmental factors may contribute significantly to the frequency and clinical manifestations of these infections. Among possible environmental features, the presence of inorganic particles with immunomodulatory properties in the skin may be a significant factor.

Atypical cutaneous leishmaniasis in Central America: possible interaction between infectious and environmental elements

Biopsies of 71 cases of atypical cutaneous leishmaniasis from Costa Rican patients were evaluated by histopathological procedures and attempts were made to culture Leishmania from nine biopsies. Leishmanin skin tests were carried out in 31 patients and 112 healthy individuals. Additional biopsies from 19 patients from Nicaragua were evaluated by routine histopathology. Ten biopsies were studied by confocal and nine by scanning electron microscopy. Inorganic material was analysed using an electron probe for microanalysis. Leishmania parasites were isolated from only two biopsies, but 90.3% of the patients from Costa Rica were leishmanin-positive, as were 27.7% of healthy individuals. Routine histopathological studies revealed naked granulomas formed by differentiated macrophages. Abundant inorganic material was observed in sections examined by confocal microscopy. Electron probe analysis revealed that silica and aluminium were the predominant elements in large particles. We postulate that the presence of this inorganic material, possibly of volcanic origin, in the skin may modulate the immunological response to Leishmania and may inhibit visceralization in the cases caused by Leishmania chagasi.

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.

Controlling the onset of natural cryptosporidiosis in calves with paromomycin sulphate

A prospective, controlled-blind field trial was conducted to evaluate the efficacy and safety of paromomycin sulphate, given for 10 days from birth, in preventing natural cryptosporidiosis in calves. In the untreated control group, oocyst shedding and diarrhoea followed the pattern that had occurred on the farm before the trial, consistent with a perinatal infection, whereas in the treated group, the prepatent period was significantly longer than in the control group (P < 0.01) and oocyst shedding and diarrhoea started only after the drug was withdrawn. However, the regimen did not reduce the incidence of disease in the treated group.

Topical treatment with hexadecylphosphocholine (Miltex) efficiently reduces parasite burden in experimental cutaneous leishmaniasis

Ether-lipids and alkylphosphocholines have been found to have anti-leishmanial activity. Oral treatment with hexadecylphosphocholine (HePC) efficiently reduces parasite burden in murine visceral leishmaniasis. Drugs for the treatment of cutaneous leishmaniasis are most commonly administered parenterally, whereas efficient drugs for topical treatment are not in current use. Here we investigate the efficacy of topical treatment with HePC in mice infected with Leishmania mexicana or L. major, causative agents of cutaneous leishmaniasis in the New and Old World, respectively. BALB/c, CBA/J and C57BL/6 inbred mice do not control infection with L. mexicana because they do not mount an efficient Th1-type anti-parasitic lymphocyte response. In contrast, C57BL/6 mice are resistant to an infection with L. major, developing only transient lesions that heal spontaneously owing to an efficient Th1 response. BALB/c, CBA/J and C57BL/6 mice were infected subcutaneously with L. mexicana amastigotes, causing nodular lesions after 5 months. Topical treatment with HePC (Miltex) was highly effective in reducing parasite burden and healed established lesions. The treatment did not induce a Th1 response in L. mexicana-infected susceptible mice and most of the mice relapsed. In resistant C57BL/6 mice infected subcutaneously with 2 x 10(6) L. major promastigotes at the tail base, nodular lesions developed after 2 weeks. Topical treatment with Miltex reduced the parasite load and the mice healed their lesions much faster than the untreated infected controls. The clinical application of Miltex for treatment of cutaneous leishmaniasis may be highly efficient because humans, similarly to resistant mice, in general do not relapse after healing. Clinical trials should be straightforward considering that Miltex is an approved drug for the treatment of breast cancer metastases.

Efficacious topical treatment for murine cutaneous leishmaniasis with ethanolic formulations of amphotericin B

The goal of the present study was to evaluate the antileishmanial effects of topically applied lipid-based formulations containing amphotericin B (AmB) in CBA mice as a model for human cutaneous leishmaniasis. Such treatment, if efficacious, is expected to be superior to systemic treatments since, by acting in a localized manner, it will require lower, and therefore less toxic, drug dosages. Three preparations of AmB complexed to polar lipids were tested: Fungizone (mixed micelles composed of AmB and deoxycholate), Amphocil (AmB and cholesteryl sulfate complex), and ABPLC (AmB and phospholipid complex). All these formulations killed parasites in vitro with similar efficacies but were ineffective when they were applied topically. However, Amphocil and ABPLC, but not Fungizone, when dispersed in an aqueous solution containing 5 to 25% ethanol, induced a statistically significant improvement in lesion size from week 2 or 3 onward (a total of 15 mg of AmB per kg of body weight was applied over 3 weeks). AmB biodistribution measurements following topical application of Amphocil, determined by high-pressure liquid chromatography, showed that AmB was detectable in the skin but not in the internal organs. Application of at least 10 times more drug was necessary to obtain detectable levels of AmB in the internal organs. After application of therapeutic doses of ABPLC, very low levels of AmB were detected in the internal organs. These experiments show for the first time that AmB administered topically as a complex either with cholesteryl sulfate or with phospholipids and in the presence of ethanol can penetrate the skin and kill sensitive organisms in a localized manner by using very low total drug concentrations.

Single-step multiplex PCR assay for characterization of New World Leishmania complexes

We have developed a PCR assay for one-step differentiation of the three complexes of New World Leishmania (Leishmania braziliensis, Leishmania mexicana, and Leishmania donovani). This multiplex assay is targeted to the spliced leader RNA (mini-exon) gene repeats of these organisms and can detect all three complexes simultaneously, generating differently sized products for each complex. The assay is specific to the Leishmania genus and does not recognize related kinetoplastid protozoa, such as Trypanosoma cruzi, Trypanosoma brucei, and Crithidia fasciculata. It correctly identified Leishmania species with a broad geographic distribution in Central and South America. The sensitivity of the PCR amplification ranged from 1 fg to 10 pg of DNA (0.01 to 100 parasites), depending on the complex detected. Crude extracts of cultured parasites, prepared simply by boiling diluted cultures, served as excellent templates for amplification. Crude preparations of clinical material were also tested. The assay detected L. braziliensis in dermal scrapings from cutaneous leishmanial lesions, Leishmania chagasi in dermal scrapings of atypical cutaneous leishmaniasis, and L. mexicana from lesion aspirates from infected hamsters. We have minimized the material requirements and maximized the simplicity, rapidity, and informative content of this assay to render it suitable for use in laboratories in countries where leishmaniasis is endemic. This assay should be useful for rapid in-country identification of Leishmania parasites, particularly where different Leishmania complexes are found in the same geographical area.