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

Unveiling the hidden burden: Exploring the psychosocial impact of cutaneous leishmaniasis lesions and scars in southern Ethiopia

BACKGROUND

Cutaneous leishmaniasis (CL) poses a major public health concern in Ethiopia, with lesions and scars commonly affecting exposed body parts, resulting in physical, social, and psychological consequences. This study aims to assess the psychosocial impacts of CL, shedding light on the experiences and perceptions of affected individuals, thus contributing to the knowledge on Cutaneous leishmaniasis in Ethiopia and informing public health interventions to address its psychosocial effects.

METHODS

Using a descriptive phenomenological design, the study explored the lived experiences of individuals with Cutaneous leishmaniasis lesions and scars. Participants were purposively selected, and data was collected through open-ended in-depth interviews. The analysis combined inductive and deductive approaches through an iterative process, developing a coding framework with seven themes (lesion & CL scar each) and subthemes, resulting in giving important insights in the psychosocial impacts of CL. NVivo 12v supported the analysis process.

RESULT

The study unveiled negative views and misconceptions surrounding CL and its impact. Application of traditional herbal medicine for CL lesions often leads to pus formation and a foul odour, triggering negative attitudes from others, resulting in embarrassment, pain, and anxiety, leading to discomfort and isolation. The negative psychosocial attitudes associated with CL scars deeply impacted affected individuals, influencing their behaviour. This included isolation and absenteeism from school. CL scars served as unique identifiers, shaping the affected individuals' identity and self-perception. The unreceptive environment affected the participant's self-esteem and coping mechanisms. The negative impact of CL scars extended to role performance, marriage prospects, and overall happiness, particularly for females facing additional societal pressure and stigma.

CONCLUSION

The study highlights the need for improved education and awareness about CL to reduce misconceptions and negative attitudes towards affected individuals. Additionally, more effective treatment options and integrated preventive ways should be explored to minimize the physical and psychological impact of CL on affected individuals.

Prevalence and risk factors of cutaneous leishmaniasis in a newly identified endemic site in South-Ethiopia

BACKGROUND

Although there are several areas in southern Ethiopia environmentally favourable for cutaneous leishmaniasis (CL), studies on the existence and risk factors of CL are lacking beyond a few well-known hotspots. This study aimed to assess the prevalence and risk factors of CL in Bilala Shaye, a village in the southern Ethiopian highlands at an altitude of 2,250 meters.

METHODS

A cross-sectional house-to-house survey was done between July-August 2021. Those with skin lesions were clinically assessed and data on individual risk behaviour and environmental and household features were collected using questionnaires. Univariate and multivariable logistic regression models were used to identify independent risk factors of CL at a 5% significance level with two-sided P-values <0.05 considered statistically significant.

RESULT

A total of 1012 individuals were interviewed; the median age was 23 years (interquartile range 12-50), with 7% below the age of five; 51% were female. All households had domestic animals, and for 143 (57%) households goats/sheep lived inside or around the house. Animal dung was found in the compounds of 194 (77%) households. The overall prevalence of active CL was 2.5% (95% confidence interval (CI) 1.6-3.6), reaching 6.7% (95% CI 3.6-11.2) in children between 5-12 years old. The prevalence of CL scars was 38.5% (95% CI 35.5-41.6). In multivariate analysis, the presence of animal dung in the compound (adjusted odds ratio (OR) 2.1; 95% CI: 1.3-3.5, P = 0.003) and time spent outside in the late evening in areas where hyraxes live (adjusted OR 2.4; 95% CI: 1.7-3.3, P <0.001) were identified as independent risk factors.

CONCLUSION

This is the first report on the existence of CL in this village, with the high prevalence of CL scars indicating long-term endemicity. Further studies are needed to understand the role of animals and their dung in (peri)-domestic CL transmission.

Protocol for a prospective observational cohort study of cutaneous leishmaniasis in Ethiopia

Background

Cutaneous leishmaniasis (CL) is a skin neglected tropical disease, with an estimated 40,000 new cases each year in Ethiopia. CL causes ulcers, nodules, and plaques on the skin, and in some instances the destruction of the nasopharyngeal mucosa and cartilage. Some CL lesions may heal spontaneously, whilst other lesions may require therapies which are associated with discomfort, adverse effects, prolonged treatment, and a frequent lack of a complete response. Scarring, a sequela of CL, causes permanent disfigurement and is associated with stigma linked with a reduction in health-related quality of life.The choice of treatment for CL is based upon factors including the causative species; the number, extent, size, and location of lesions; and the availability of treatments. The development of robust evidence for CL treatment is hindered by a lack of validated and appropriate outcome measures and few data to support hypothesis-generation and trial design. There is a paucity of prospective data with well-defined treatment outcomes for CL caused by L. aethiopica.

Aim

The overall aim of this study is to improve the understanding of the health and economic burden of CL.

Methods

We have designed an observational, multi-centre cohort study to examine treatment outcomes for CL in Ethiopia which includes clinical outcomes, laboratory outcomes, patient reported outcome measures, scar assessments and cost effectiveness. We aim to recruit up to 750 participants across two hospital sites. We present here the protocol for this cohort study with a 12-month follow up period for each participant.

Conclusions

These data will inform the design of randomized controlled trials to evaluate new treatment strategies, with appropriate economic evaluations. This will help improve evidence-based guidelines and support evidence-led policy decisions, not only in Ethiopia but also globally.

A case of adnexal cutaneous leishmaniasis in Washington DC

PURPOSE

To report a rare non-endemic case of Leishmania aethiopica in Washington DC.

CASE REPORT

A 68-year-old female presented for a routine examination with a complaint of right upper eyelid lesions for the past 5 months. On examination, a cluster of elevated and erythematous lesions extending from the medial canthus to the brow area of the right eye were seen. Initial treatment with Valtrex based on a suspected viral etiology failed. Although a biopsy was recommended at this time, the patient declined, and subsequent workup included nasolacrimal duct irrigation, blood work to rule out autoimmune etiology, a course of doxycycline, and an MRI, which yielded no improvement. Upon progression of the lesions into persistent plaques on the eyelids, a punch biopsy was performed, confirming leishmaniasis. The patient was then started on a 28-day course of oral miltefosine which led to complete resolution of her symptoms.

CONCLUSION

This case underlines the importance of a broad differential including non-endemic diseases, particularly in urban areas with frequent patient travel. Furthermore, the delayed punch biopsy in this case highlights the importance of patient counseling to ensure prompt diagnosis and treatment.

Medicinal plants with promising antileishmanial activity in Ethiopia: A systematic review and meta-analysis

INTRODUCTION

Toxicity and resistance to chemotherapy used to treat leishmaniasis are increasing. Research on natural plant compounds has revealed their antileishmanial effects on certain Leishmania organisms. This review aimed to estimate the pooled IC50 values of medicinal plants with promising antileishmanial activity in Ethiopia.

METHODS

A systematic literature search was conducted using Science Direct, PubMed, Cochrane Library, and Google Scholar to locate potential studies. Studies published in peer-reviewed journals and gray literature in university repositories before April 1, 2022, which included a full-length study reporting the half-maximal inhibitory concentration (IC50) of Ethiopian medicinal plants that were written in English were included. Conference proceedings, review articles, letters to the editor, and correspondence were excluded. The quality of the included studies was assessed using the GIVIMP critical appraisal tools. Heterogeneity between studies was verified using Cochrane Q test statistics and I2 test statistics, and the effects were checked using Egger statistical test at a level of significance. A random-effects model was used to estimate the pooled IC50 of the medicinal plants.

RESULTS

Six articles that were conducted in Ethiopia that fulfilled the inclusion criteria, with a total of 62 in vitro experiments, were reviewed. The aggregated mean IC50 for medicinal plants in Ethiopia was 16.80 (95% CI: 12.44, 21.16) and 13.81 (95% CI: 13.12, 14.50) µg/mL for antipromastigote and antiamastigote activity, respectively. Aqueous was the significant preparation with IC50 of 0.53 (0.34, 0.73) µg/mL against promastigote and 0.98 (0.20, 1.76) µg/mL against the amastigote stage.

DISCUSSION

This review indicated that the pooled mean of IC50 for Ethiopian medicinal plants against promastigotes and amastigotes was relatively low and showed better efficacy. This strongly suggests the need to focus on antipromastigote and antiamastigote medicinal plants in Ethiopia for the development of antileishmanial drugs. It is necessary to identify their active components, and their potential toxic effects can lead to the production of well-tolerated and safe drugs for leishmaniasis. The high heterogeneity is the limitation of this study.

REGISTRATION

The review has been registered at Prospero with identification number CRD42022343543.

In vitro antileishmanial activities of hydro-methanolic crude extracts and solvent fractions of Clematis simensis fresen leaf, and Euphorbia abyssinica latex

As a result of increasing drug resistance, crossover resistance development, prolonged therapy, and the absence of different agents with innovative methods for implementation, the efficacy of recent antileishmanial medications is severely declining. So, it is vital to look for other medications from botanical remedies that have antileishmanial activity. The latex of Euphorbia abyssinica (E abyssinica) and the leaves of Clematis simensis fresen (C simensis) were macerated in methanol (80%). In vitro antileishmanial activity of the preparation was tried on promastigotes of Leishmania aethiopica (L aethiopica) and Leishmania donovani (L donovani) using resazurin assay, and fluorescence intensity was measured. One percent of dimethyl sulfoxide (DMSO) and media as negative control and amphotericin B as positive control were used. Additionally, hemolytic & phytochemical tests of the preparation were done. The mean and standard errors of each extract were evaluated and interpreted for statistical significance using one-way analysis of variance. From sigmoidal dose-response curves of % inhibition, half maximal inhibitory concentration (IC50) values were determined by GraphPad Prism and Microsoft Excel; outcomes were presented as mean ± standard error of mean of triplicate trials. P < .05 was statistical significance. The phytochemical screening of C simensis and E abyssinica confirmed the existence of steroids, phenols, tannins, saponins, alkaloids, terpenoids, flavonoids and glycosides. C simensis possesses antileishmanial activity with IC50 outcomes of 46.12 ± 0.03 and 8.18 ± 0.10 µg/mL on the promastigotes of L aethiopica and L donovani, respectively. However, E abyssinica showed stronger activity with IC50 outcomes of 16.07 ± 0.05 µg/mL and 4.82 ± 0.07 µg/mL on L aethiopica and L donovani, respectively. C simensis and E abyssinica have a less hemolytic effect on human red blood cells at low concentrations. The outcomes from this investigation demonstrated that the preparation of C simensis and E abyssinica indicated significant antileishmanial activity. Therefore, further in vivo assessment of antileishmanial, cytotoxicity activity and quantitative identification of secondary metabolites are highly recommended.

Comparative Efficacy of Intralesional Chloroquine With Intralesional Meglumine Antimoniate in the Treatment of Cutaneous Leishmaniasis

BACKGROUND AND AIM

This comparative prospective study was conducted at the Department of Dermatology, Pak Emirates Military Hospital, Rawalpindi, from August 1, 2018, to January 31, 2019 (six months). This study aimed to compare the efficacy of intralesional chloroquine with intralesional meglumine antimoniate in the treatment of cutaneous leishmaniasis.

MATERIALS AND METHODS

A total of 64 patients fulfilling the inclusion criteria reporting to the Department of Dermatology, Pak Emirates Military Hospital were included in this study. Informed consent was taken and demographic data including patients' hospital registration number, age, gender, and number of lesions were noted. The subjects were randomly assigned into two groups. In group A, intralesional chloroquine was injected two times per week, and in group B, intralesional meglumine antimoniate was injected two times per week. The efficacy of both treatments was noted after eight weeks of treatment. Frequency and percentages were computed for qualitative variables like gender and number of lesions. Mean±standard deviation was presented for quantitative variables like age. Analysis was done to compare the proportion of both groups. Chi-square test was applied to compare the efficacy of both groups, p≤0.05 was taken as significant.

RESULTS

In this study, the mean age of patients was 29.69±08.95 years. There were 63 (98.44%) males and one (1.56%) female. In this study, efficacy was achieved in six (18.8%) patients in group A, while in 17 (53.1%) patients in group B. This difference was statistically significant, i.e., p=0.004.

CONCLUSION

This study concluded that intralesional meglumine antimoniate is more effective in treating cutaneous leishmaniasis than intralesional chloroquine.

Treatment outcomes of cutaneous leishmaniasis due to Leishmania aethiopica: A systematic review and meta-analysis

BACKGROUND

Leishmania aethiopica is a unique species that causes cutaneous leishmaniasis (CL), and studies evaluating treatment outcomes for this condition reported inconsistent findings. This study aimed to summarize the evidence on treatment outcomes of CL caused by L. aethiopica to support decisions or propose further study.

METHODS

We searched PubMed, Scopus, and ScienceDirect. In addition, we searched grey literature on Google Scholar and performed manual searching on the reference list of articles. Two authors did the screening, selection, critical appraisal, and data extraction. With the narrative synthesis of evidence, we performed a random effects model meta-analysis using the metaprop package in Stata 17. We did sensitivity and subgroup analyses after assessing heterogeneity using the I-squared test and forest plots. The funnel plot and Egger's test were used to assess publication bias.

RESULTS

The review included 22 studies with 808 participants, and the meta-analysis included seven studies with 677 participants. Most studies documented treatment outcomes with antimonial monotherapy, and only one study reported outcomes with combination therapy. The overall pooled proportion of cure was 63% (95% CI: 38-86%). In the subgroup analysis, systemic antimonial monotherapy showed a cure rate of 61%, and the proportion of cure was 87% with topical therapy. Topical therapy showed a better cure for the localized clinical phenotype. A cohort study documented a cure rate of 94.8% with combination therapy for the localized, mucocutaneous, and diffuse clinical phenotypes. The pooled proportion of unfavourable outcomes was partial response (19%), relapse (17%), discontinuation (19%), and unresponsiveness (6%).

CONCLUSIONS

The pooled proportion of cure is low with antimonial monotherapy. Despite limited evidence, combination therapies are a promising treatment option for all clinical phenotypes of CL caused by L. aethiopica. Future high-quality randomized control trials are needed to identify effective monotherapies and evaluate the effectiveness of combination therapies.

Health-related quality of life of adults with cutaneous leishmaniasis at ALERT Hospital, Addis Ababa, Ethiopia

BACKGROUND

Cutaneous leishmaniasis (CL) is a growing public health threat in Ethiopia. Leishmania aethiopica is the predominant causative organism. Affected individuals develop chronic skin lesions on exposed parts of the body, mostly on the face, which are disfiguring and cause scarring. The effects of CL on the health-related quality of life (HRQoL) of affected individuals has not been assessed in Ethiopia.

OBJECTIVE

To assess HRQoL in adults with active CL at ALERT Hospital, Addis Ababa, Ethiopia.

METHODS

A cross-sectional study was done using the Amharic version of the Dermatology Life Quality Index (DLQI). Trained health staff administered the DLQI.

RESULTS

Three hundred and two adults with active CL participated and all of them exhibited a reduced HRQoL. The median DLQI score was 10 (IQR 8). Almost half of the participants reported very poor HRQoL, 36.4% and 11.3% fell within the very large and extremely large effect categories respectively. DLQI scores were higher (median 18) in patients diagnosed with diffuse cutaneous leishmaniasis (DCL) compared to those with localized cutaneous leishmaniasis (LCL). The DLQI domain of 'work and school' was the most affected, scoring 73.3% and 66.6% of total possible score for female and male respectively, followed by that of 'symptom and feeling' (at 50.0% and 56.6% for female and male respectively). Men were more affected than women in the domains of 'leisure' (P = 0.002) and 'personal relationships' (P = 0.001). In the multivariate ordinal logistic regression site of lesion, clinical phenotype and age of participant remained associated with significantly poor HRQoL.

CONCLUSION

The HRQoL impairment associated with CL is significant. Thus, patient-reported outcome measure should be used to assess the efficacy of treatments along with clinical outcome measures.

Burden of neglected tropical diseases and access to medicine and diagnostics in Ethiopia: a scoping review

BACKGROUND

More than 1.7 billion people are affected by neglected tropical diseases (NTDs) worldwide. Forty percent of the NTD-affected people live in Africa with the poorest, most vulnerable, and hard to reach geographical areas. The NTDs cause significant social and economic burden and deepen marginalization and stigmatization. The World Health Organization's current roadmap for NTD aims to prevent, control, eliminate, or eradicate 20 tropical diseases. Ethiopia experiences a high burden of these diseases, but current access to diagnostics, medicine, and/or care has been little explored to inform the country's NTD strategic plan. The overall purpose of the scoping review was to map and characterize the burden of NTDs and challenges in access to diagnostics, medicine, and/or care in Ethiopia.

METHODS

A systematic search of evidence was conducted in PubMed, Cochrane Library, and Google Scholar from January 2000 until May 2022, without restrictions of language or study design. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review was followed for screening of studies. Key findings were extracted and narrated qualitatively.

RESULTS

The search resulted in 4532 articles, of which 105 met the inclusion criteria and were included in the scoping review under three themes: burden of NTDs, access to diagnostics, medicine and/or care, and key barriers. Although gains have been made in the prevention and control of NTDs in Ethiopia, the burden remains high, and progress in access to diagnostics, medicine/drugs, and/or care is very slow. Poverty, poor quality of life, and underfunding of NTD programs decelerate the process of NTD elimination program in the country.

CONCLUSIONS

The scoping review identified a considerable number of studies on the burden of NTDs in Ethiopia and strategies for diagnosis, treatment, and/or care; however, there is a paucity of evidence on the suitability and potential benefits of novel diagnostic technologies and medicines in the country. A regular review and analysis of such country-level evidence is important to inform the country NTDs roadmap and local implementation strategies.

Treatment of Cutaneous Leishmaniasis with Sodium Stibogluconate and Allopurinol in a Routine Setting in Ethiopia: Clinical and Patient-Reported Outcomes and Operational Challenges

Cutaneous leishmaniasis (CL) is common in Ethiopia, but the national guideline does not offer specific treatment recommendations. Consequently, different treatment regimens are used in the country, without quality evidence. In Boru Meda Hospital, sodium stibogluconate (SSG) is routinely used in combination with allopurinol for systemic CL treatment, although evidence on its effectiveness is limited. An observational cohort study was carried out to document clinical treatment outcomes in patients receiving SSG/allopurinol at the end of each 28-day treatment cycle and after 180 days. Patient-reported outcomes were assessed by asking patients to rate lesion severity, and by the dermatological life quality index. A total of 104 patients were included. After one treatment cycle, only four patients were clinically cured, although patient-reported outcomes significantly improved. The majority (88) of patients were appointed for a second treatment cycle, of whom only 37 (42%) attended. Among the 36 patients who came for final outcome assessment, 50% were cured. Follow-up and treatment were severely affected by conflict; drug stock-outs and insufficient ward capacity for treatment were additional challenges. The treatment outcomes of SSG/allopurinol were relatively poor, and most patients required more than one cycle of treatment. Shortages of drugs and beds indicate the existing gaps in providing CL treatment in Ethiopia.

Cutaneous leishmaniasis in a newly established treatment centre in the Lay Gayint district, Northwest Ethiopia

Background

Cutaneous leishmaniasis (CL) is a neglected tropical disease that primarily affects the most vulnerable populations. In Ethiopia, where this study took place, CL is an important health problem, however, the incidence of CL is poorly monitored.

Objectives

This study took place in a recently established CL treatment centre, at Nefas Mewcha Hospital, Lay Gayint. This area was considered to be endemic for CL, however, no cases of CL from Lay Gayint had previously been officially reported to the Amhara Regional Health Bureau.

Methods

Following a CL awareness campaign, a retrospective data review was performed of patients presenting to this centre between July 2019 and March 2021. Basic demographic and clinical data were collected by a nurse and recorded in the logbook of the CL treatment centre.

Results

Two hundred and one patients presented for diagnosis and treatment. The age of the patients ranged from 2 to 75 years and 63.2% were males. Most patients were between 10- and 19-years-old. The majority (79.1%) of the patients presented with localised cutaneous leishmaniasis and 20.9% with mucocutaneous leishmaniasis. 98% of the patients tested positive for Leishmania parasites by microscopy.

Conclusions

This work underpinned how CL is a major public health problem in the Lay Gayint district. It also shows that raising awareness about CL in the community and providing diagnosis and treatment encouraged patients to travel to seek diagnosis and treatment.

Cutaneous leishmaniasis in Kutaber District, Ethiopia: Prevalence, sand fly fauna and community knowledge, attitude and practices

Background

Cutaneous leishmaniasis (CL) affects 25% of the population living in the highlands of Ethiopia. CL intervention has not decreased the number of leishmaniasis patients. A cross-sectional study was conducted to determine CL prevalence, community's knowledge, attitude and practices (KAP), and the sand fly fauna in Kutaber district, northeast Ethiopia.

Methods

A retrospective, community-based cross-sectional study was conducted in Boru Meda Hospital from December 2014-March 2021 to study CL prevalence of Kutaber district. A Pre-tested, well-structured questionnaire was used to collect data on the participants' socio-demographic characteristics, KAP towards CL and knowledge about sand fly vectors. Chi-square test and logistic regression analysis were used in the study, and data were analyzed using SPSS version 23 (p < 0.05).

Results

A total of 10,002 (14.02%), of which 71,325 samples were confirmed as positive for CL. The infection rate of CL in females (7.1%) was a little bit higher than males (7.0%). More cases were recorded among 15-29 age category. The study also revealed that 77.1% of the respondents had poor knowledge about CL treatment, prevention, clinical presentation and disease transmission. Farmers tended to have poorer knowledge about sand flies than non-workers and students (32.7 vs. 35 and 44.1%; P = 0.049). Housewives had poorer knowledge about sand flies than farmers and workers (22.2 vs. 32.7 and 33.3%; P = 0.023). Phlebotomus longipes comprised the highest composition (80%) of the sand fly species identified in Kutaber district.

Conclusions

The data showed that the community had poor knowledge about CL, vector, and transmission mode. CL preventive measures were prevalent, implying the need to raise CL awareness. Phlebotomus longipes was identified as the most dominant sand fly species which accounted for CL. The findings can be used in developing an effective control strategy to reduce CL transmission in the study area and elsewhere in Ethiopia.

The Extraordinary Case of a Woman with a 30-Year-Long Diffuse Leishmaniasis Cured with One Single Ampoule of Intranasal Pentavalent Antimoniate

Infection with Leishmania amazonensis and L. mexicana may lead to diffuse cutaneous leishmaniasis. The cure is exceptional, especially for the strange case of this lady. Case report: The patient acquired the disease in childhood and remained with lesions for over 30 years, albeit several treatments. She worsened after a pregnancy, developing disseminated lesions. Miltefosine with amphotericin B and pentamidine resulted in remission. Lesions reappeared after one year, accompanied by intra-nasal infiltration of the disease. The nasal spraying of a single ampoule of pentavalent antimoniate resulted in the sustained disappearance of the nasal symptoms and all the cutaneous lesions. After over eight years, she remains disease-free, albeit under renal replacement therapy. The high nasal mucosal antimonial concentration may explain the long-lasting cure via new MHC class I epitope-specific CD8+ cell clones against L. amazonensis present in the nasal mucosa.

Effectiveness of intralesional sodium stibogluconate for the treatment of localized cutaneous leishmaniasis at Boru Meda general hospital, Amhara, Ethiopia: Pragmatic trial

Background

Cutaneous leishmaniasis (CL) is generally caused by Leishmania aethiopica in Ethiopia, and is relatively hard to treat. Sodium stibogluconate (SSG) is the only routinely and widely available antileishmanial treatment, and can be used systemically for severe lesions and locally for smaller lesions. There is limited data on the effectiveness of intralesional (IL) SSG for localized CL in Ethiopia and therefore good data is necessary to improve our understanding of the effectiveness of the treatment.

Methodology/Principal findings

A pragmatic (before and after Quazi experimental) study was done to assess the effectiveness of intralesional SSG among localized CL patients at Boru Meda general hospital, Northeast Ethiopia. Patients who were assigned to intralesional SSG by the treating physician were eligible for this study. Study subjects were recruited between January and August 2021. Infiltration of intralesional SSG was given weekly to a maximum of six doses. However, when a patient’s lesions were already cured before getting 6 doses, treatment was not conintued, and patient were only asked to come for lesion assessment. Skin slit smears (SSS) were taken each week until they became negative. Outcomes were assessed at day 90, with patients who had 100% reepithelization (for ulcerative lesions) and/or flattening (for indurated lesions) defined as cured. Multi-level logistic regression was done to assess factors associated with cure.

A total of 83 patients were enrolled, and final outcomes were available for 72 (86.75%). From these 72, 43 (59.7%, 95% confidence interval 0.44–0.69) were cured at day 90. Adverse effects were common with 69/72 patients (95.8%) reporting injection site pain. Factors associated with cure were age (OR 1.07 95% CI: 1.07–1.27), being male (OR 1.79, 95% CI: 1.10–2.25), size of the lesion (OR 0.79, 95% CI: 0.078–0.94) and skin slit smear (SSS) result +1 grading (OR 1.53, 95% CI: 1.24–1.73) and +2 grading (OR 1.51, 95% CI: 1.41–3.89) compared to the SSS grade +6.

Conclusion

Our findings revealed that intralesional sodium stibogluconate resulted in a cure rate of around 60%, with almost all patients experiencing injection site pain. This emphasizes the need for local treatment options which are more patient-friendly and have better cure rates.

Effects of negative air ions (NAIs) on Leishmania major: A novel tool for treatment of zoonotic cutaneous leishmaniasis (ZCL)

Background

Cutaneous leishmaniasis (CL) is a Neglected Tropical Disease (NTD) that causes high morbidity in the tropics and sub-tropics. Despite the remarkable advancements in the treatment of CL, the available therapeutics are far from ideal and also cause serious adverse side effects. Negative air ions (NAIs) generators are widely available for domestic and industrial uses. Several studies have reported on positive effects of NAIs therapy on human health as a non-pharmaceutical treatment for respiratory disease, allergy, or stress-related health conditions, including infectious diseases. To our knowledge, no studies have examined the effectiveness of the NAIs therapy against Leishmania parasites. The aims of this study were to investigate the effect of NAIs therapy on Leishmania major (L. major) the causative agent of CL in in vitro and in a murine model.

Methodology/Principal findings

In vitro anti-leishmanial effects of NAIs therapy were measured by parasitological methods. NAIs therapy was assessed in vivo in L. major infected BALB/c mice by measuring the footpad (FP) lesion size and parasite load using metric caliper tool and qPCR, respectively. Immune responses in treated and non-treated mice were assessed by measuring the levels of IFN-γ, IL-4, NO and arginase activity. In vitro NAIs therapy significantly decreased the viability of Leishmania promastigotes and of amastigotes cultured in macrophages, but did not affect the host cells. NAIs therapy of L. major infected BALB/c mice resulted in reduced FP lesion size, diminished parasite burden, and importantly decreased induction of IL-4 and arginase activity in the presence of NAIs. In contrast IFN-γ and NO levels were significantly enhanced. NAIs therapy significantly diminished the progression of disease compared to the control group, but was less effective than amphotericin B treatment.

Conclusions

Our study shows that NAIs treatment was effective in vitro and in Leishmania-infected mice, elicited a T-helper 1 (Th1) response and increased efficient cellular immunity, resulting in a diminished parasite load. Therefore, NAIs therapy can be considered as a useful and safe tool that can contribute to clearing L. major infections without inducing toxicity in host cells. The applications and mechanisms of NAIs therapy warrant further investigation especially in humans suffering from CL.

Making the Most of Its Short Reads: A Bioinformatics Workflow for Analysing the Short-Read-Only Data of Leishmania orientalis (Formerly Named Leishmania siamensis) Isolate PCM2 in Thailand

Simple Summary

Leishmaniasis is a parasitic disease caused by flagellated protozoa of the genus Leishmania. Multiple genome sequencing platforms have been employed to complete Leishmania genomes at the expense of high cost. This study proposes an integrative bioinformatic workflow for assembling only the short-read data of Leishmania orientalis isolate PCM2 from Thailand and produce an acceptable-quality genome for further genomic analysis. This workflow gives extensive information required for identifying strain-specific markers and virulence-associated genes useful for drug and vaccine development before a more exhaustive and expensive investigation.

Abstract

Background: Leishmania orientalis (formerly named Leishmania siamensis) has been neglected for years in Thailand. The genomic study of L. orientalis has gained much attention recently after the release of the first high-quality reference genome of the isolate LSCM4. The integrative approach of multiple sequencing platforms for whole-genome sequencing has proven effective at the expense of considerably expensive costs. This study presents a preliminary bioinformatic workflow including the use of multi-step de novo assembly coupled with the reference-based assembly method to produce high-quality genomic drafts from the short-read Illumina sequence data of L. orientalis isolate PCM2. Results: The integrating multi-step de novo assembly by MEGAHIT and SPAdes with the reference-based method using the L. enriettii genome and salvaging the unmapped reads resulted in the 30.27 Mb genomic draft of L. orientalis isolate PCM2 with 3367 contigs and 8887 predicted genes. The results from the integrated approach showed the best integrity, coverage, and contig alignment when compared to the genome of L. orientalis isolate LSCM4 collected from the northern province of Thailand. Similar patterns of gene ratios and frequency were observed from the GO biological process annotation. Fifty GO terms were assigned to the assembled genomes, and 23 of these (accounting for 61.6% of the annotated genes) showed higher gene counts and ratios when results from our workflow were compared to those of the LSCM4 isolate. Conclusions: These results indicated that our proposed bioinformatic workflow produced an acceptable-quality genome of L. orientalis strain PCM2 for functional genomic analysis, maximising the usage of the short-read data. This workflow would give extensive information required for identifying strain-specific markers and virulence-associated genes useful for drug and vaccine development before a more exhaustive and expensive investigation.

Establish an allele-specific real-time PCR for Leishmania species identification

Background

Leishmaniasis is a serious neglected tropical disease that may lead to life-threatening outcome, which species are closely related to clinical diagnosis and patient management. The current Leishmania species determination method is not appropriate for clinical application. New Leishmania species identification tool is needed using clinical samples directly without isolation and cultivation of parasites.

Methods

A probe-based allele-specific real-time PCR assay was established for Leishmania species identification between Leishmania donovani and L. infantum for visceral leishmaniasis (VL) and among L. major, L. tropica and L. donovani/L. infantum for cutaneous leishmaniasis (CL), targeting hypoxanthine-guanine phosphoribosyl transferase (HGPRT) and spermidine synthase (SPDSYN) gene with their species-specific single nucleotide polymorphisms (SNPs). The limit of detection of this assay was evaluated based on 8 repeated tests with intra-assay standard deviation < 0.5 and inter-assay coefficients of variability < 5%. The specificity of this assay was tested with DNA samples obtained from Plasmodium falciparum, Toxoplasma gondii, Brucella melitensis and Orientia tsutsugamushi. Total 42 clinical specimens were used to evaluate the ability of this assay for Leishmania species identification. The phylogenetic tree was constructed using HGPRT and SPDSYN gene fragments to validate the performance of this assay.

Results

This new method was able to detect 3 and 12 parasites/reaction for VL and CL respectively, and exhibited no cross-reaction with P. falciparum, T. gondii, B. melitensis, O. tsutsugamushi and non-target species of Leishmania. Twenty-two samples from VL patients were identified as L. donovani (n = 3) and L. infantum (n = 19), and 20 specimens from CL patients were identified as L. major (n = 20), providing an agreement of 100% compared with sequencing results. For further validation, 29 sequences of HGPRT fragment from nine Leishmania species and 22 sequences from VL patients were used for phylogenetic analysis, which agreed with the results of this new method. Similar results were obtained with 43 sequences of SPDSYN fragment from 18 Leishmania species and 20 sequences from CL patients.

Conclusions

Our assay provides a rapid and accurate tool for Leishmania species identification which is applicable for species-adapted therapeutic schedule and patient management.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-00992-y.

Tackling Drug Resistance and Other Causes of Treatment Failure in Leishmaniasis

Leishmaniasis is a tropical infectious disease caused by the protozoan Leishmania parasite. The disease is transmitted by female sand flies and, depending on the infecting parasite species, causes either cutaneous (stigmatizing skin lesions), mucocutaneous (destruction of mucous membranes of nose, mouth and throat) or visceral disease (a potentially fatal infection of liver, spleen and bone marrow). Although more than 1 million new cases occur annually, chemotherapeutic options are limited and their efficacy is jeopardized by increasing treatment failure rates and growing drug resistance. To delay the emergence of resistance to existing and new drugs, elucidating the currently unknown causes of variable drug efficacy (related to parasite susceptibility, host immunity and drug pharmacokinetics) and improved use of genotypic and phenotypic tools to define, measure and monitor resistance in the field are critical. This review highlights recent progress in our understanding of drug action and resistance in Leishmania, ongoing challenges (including setbacks related to the COVID-19 pandemic) and provides an overview of possible strategies to tackle this public health challenge.

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.

Diagnosis of visceral and cutaneous leishmaniasis using loop-mediated isothermal amplification (LAMP) protocols: a systematic review and meta-analysis

Sensitive, reliable and fast diagnostic tools that are applicable in low-resource settings, at the point of care (PoC), are seen as crucial in the fight against visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). Addressing the need for a PoC test, several diagnostic tests, including serological and molecular methods, have been developed and evaluated in the past. One promising molecular method, already implemented for diagnosis of a range of diseases, is the loop-mediated isothermal amplification (LAMP) protocol. In this systematic review and meta-analysis, using a comprehensive search strategy, we focus on studies evaluating the performance of LAMP for the diagnosis of leishmaniasis in humans and other mammals such as dogs, compared with microscopy and/or any other molecular diagnostic method. A meta-analysis, pooling sensitivity and specificity rates and calculating areas under the curve (AUCs) in summary receiver operating characteristic (SROC) plots, was conducted on datasets extracted from studies, grouped by clinical condition and sample type. We found high sensitivity and specificity for LAMP when compared with microscopy and PCR using blood samples, with pooled estimate values of > 90% for all subgroups, corresponding to calculated AUC values > 0.96, except for LAMP compared to microscopy for diagnosis of CL. However, only a limited number of studies were truly comparable. Most of the observed heterogeneity is likely based on true differences between the studies rather than sampling error only. Due to simple readout methods and low laboratory equipment requirements for sample preparation compared to other molecular methods, LAMP is a promising candidate for a molecular (near-)PoC diagnostic method for VL and CL.

In vitro growth inhibitory activity of Medicines for Malaria Venture pathogen box compounds against Leishmania aethiopica

Introduction

Leishmania aethiopica (L. aethiopica) is responsible for different forms of cutaneous leishmaniasis (CL) in Ethiopia. Treatment heavily depends on limited drugs, together with drawbacks like toxicity and microbial resistance. The current research aimed to investigate in vitro growth inhibitory activity of Medicines for Malaria Ventures - Pathogen Box (MMV - PB) compounds against L. aethiopica clinical isolate.

Methodology

Four hundred MMV – PB compounds were screened against L. aethiopica using resazurin based colourimetric assay. Compounds with > 70% inhibition were further tested using macrophage based intracellular amastigote assay. Cytotoxic and hemolytic activity of candidate hits were assessed on THP1- cells and sheep red blood cells (RBCs), respectively. In vitro drug interaction study was also conducted for the most potent hit using the combination index method.

Results

At the test concentration of 1 μM, twenty-three compounds showed > 50% inhibition of promastigotes parasite growth, of which 11 compounds showed > 70% inhibition. The 50% growth inhibition (IC₅₀) of the 11 compounds was ranged from 0.024 to 0.483 μM in anti-promastigote assay and from 0.064 to 0.899 μM in intracellular amastigote assay. Candidate compounds demonstrated good safety on sheep RBCs and THP-1 cell lines. MMV688415 demonstrated a slight hemolytic activity on sheep RBC (5.3% at 25 μM) and THP-1 cell line (CC₂₀ = 25 μM) while MMV690102 inhibited half of THP-1 cells at 36.5 μM (selectivity index = 478). No synergistic activity was observed from the combinations of MMV690102 and amphotericin B (CI > 1), and MMV690102 and Pentamidine (CI > 1) at lower and higher combination points.

Conclusion

The present study identified a panel of compounds that can be used as a novel starting point for lead optimization. MMV690102 appears to be the most potent inhibitor against L. aethiopica promastigotes and amastigotes. Future works should investigate the antileishmanial mechanism of action and in vivo antileishmanial activities of identified hits.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40360-021-00538-2.

Efficacy and safety of pentamidine isethionate for tegumentary and visceral human leishmaniasis: a systematic review

RATIONALE FOR REVIEW

We performed a systematic review of the literature to investigate the efficacy and safety of pentamidine isethionate for the treatment of human tegumentary and visceral leishmaniasis.

KEY FINDINGS

A total of 616 papers were evaluated, and 88 studies reporting data on 3108 cases of leishmaniasis (2082 patients with tegumentary leishmaniasis and 1026 with visceral leishmaniasis) were finally included. The majority of available studies were on New World cutaneous leishmaniasis and visceral leishmaniasis caused by Leishmania donovani. At the same time, few data are available for Old World cutaneous leishmaniasis, mucosal leishmaniasis, and visceral leishmaniasis caused by L. infantum. Pooled cure rate for tegumentary leishmaniasis was 78.8% (CI 95%, 76.9-80.6%) and 92.7% (CI 95%, 88.3-97.1%) according to controlled randomized trial and observational studies and case report and case series respectively. Pooled cure rate for visceral leishmaniasis was 84.8% (CI 95%, 82.6-87.1%) and 90.7% (CI 95%, 84.1-97.3%) according to controlled randomized trial and observational studies and case report and case series, respectively. Comparable cure rate was observed in recurrent and refractory cases of visceral leishmaniasis. Concerning the safety profile, among about 2000 treated subjects with some available information, the most relevant side effects were six cases of arrhythmia (including four cases of fatal ventricular fibrillation), 20 cases of irreversible diabetes, 26 cases of muscular aseptic abscess following intramuscular administration.

CONCLUSIONS/RECOMMENDATIONS

Pentamidine isethionate is associated with a similar cure rate of the first-line anti-leishmanial drugs. Severe and irreversible adverse effect appear to be rare. The drug may still have a role in the treatment of any form of human leishmaniasis when the first-line option has failed or in patients who cannot tolerate other drugs also in the setting of travel medicine. In difficult cases, the drug can also be considered as a component of a combination treatment regimen.

Miltefosine for the treatment of cutaneous leishmaniasis-A pilot study from Ethiopia

Background

Cutaneous leishmaniasis (CL) in Ethiopia, caused by Leishmania aethiopica, is often severe and hard to treat compared to CL caused by other species elsewhere. Miltefosine is the only oral anti-leishmanial drug, with a favorable side-effect profile compared to routinely available sodium stibogluconate (SSG), but evidence about its use for L. aethiopica is lacking.

Methodology and principal findings

In an observational cohort study, treatment outcomes, safety and adherence among CL patients who required systemic treatment and received miltefosine for 28 days in Boru Meda Hospital and University of Gondar Hospital were studied. Patient cure was defined as 100% flattening for non-ulcerated lesions and 100% flattening and 100% re-epithelization for ulcerated lesions. Outcomes were documented for day 28, 90 and 180, both per site, and pooled, adjusting for site as a fixed effect with effect coding. Among 94 included patients (32 in Gondar, 62 in Boru Meda), median lesion duration was 12 months, median size six cm, and mucosal involvement (46.8%) and diffuse (30.9%) lesions were common. Adherence to miltefosine was good, and side-effects were tolerable. Initial outcomes at day 28 were promising, with 68.8% and 94.0% of patients having good improvement or cure in Gondar and Boru Meda respectively. In Boru Meda, outcomes were good with 72.7% and 72.9% cure at day 90 and day 180 respectively. In Gondar, results were less promising, with only 12.5% and 26.7% cure at day 90 and day 180, although confidence intervals were wide. In pooled estimates, 48.7% of patients reached cure at day 180, and 32.3% relapsed. Outcomes were better in Boru Meda Hospital, for smaller lesions and for mucosal lesions.

Conclusions/Significance

Based on miltefosine’s good initial response, tolerable side-effects, tablet-form, we propose to include miltefosine for future clinical trials using extended treatment schedules, combination therapy, or targeting specific subgroups.

Trial registration

ClinicalTrials.gov NCT04004754.

Cutaneous leishmaniasis (CL) in Ethiopia is caused by Leishmania aethiopica, resulting in relatively severe lesions, which are hard to treat. Currently, most patients are treated with pentavalent antimonials, although effectiveness seems poor, with many patients requiring repeated treatment cycles before good response is seen. Miltefosine is the only oral drug available for leishmaniasis treatment and has a good safety profile compared to other treatment options. Although evidence on the use of miltefosine for CL in other regions looks promising, reports from Ethiopia are lacking.

We systematically recorded outcomes and side-effects for patients with CL lesions that required systemic treatment and who were treated with 28 days of miltefosine in a prospective study in two hospitals in Ethiopia. Side-effects were common but generally mild. Although all patients showed improvement after 28 days, overall, around half of patients were cured after six months, with relapse being common. Therefore, we propose to include miltefosine in future clinical trials, but to adapt the treatment regimen using combination therapy or treatment extension to improve overall outcomes and reduce relapse.

The effect of oral miltefosine in treatment of antimoniate resistant anthroponotic cutaneous leishmaniasis: An uncontrolled clinical trial

Background

Recent circumstantial evidence suggests increasing number of Iranian patients with cutaneous leishmaniasis (CL) who are unresponsive to meglumine antimoniate (MA), the first line of treatment in Iran. Oral meltifosine was previously reported to be effective in visceral leishmaniasis as well CL. The current study is designed to determine efficacy and safety of oral miltefosine for the treatment of anthroponotic cutaneous leishmaniasis (ACL) cases who were refractory to MA in Iran.

Methodology/Principal findings

Miltefosine was orally administered for 27 patients with MA resistant ACL with approved L.tropica infection, at a dosage of ∼2.5 mg/kg daily for 28 days. Patients were evaluated on day 14 and 28, as well as 3, 6 and 12 month post treatment follow up sessions. Laboratory data were performed and repeated at each visit. Data were analyzed using SPSS version 17. Twenty-seven patients including 16 men (59.25%) and 11 women (40.74%) with mean age of 28.56 ± 4.8 (range 3–54 years old) were enrolled. Total number of lesions were 42 (1–4 in each patient). Most of lesions were on face (76.19%). Mean lesions’ induration size was 2.38 ± 0.73 cm at the base-line which significantly decreased to1.31 ± 0.58 cm and 0.61 ±0.49 cm after 14 and 28 days of therapy, respectively (p value <0.05). At 12-months follow-up post treatment, 22 patients had definite/partial cure (81.48%) including 17 definitely cured patients, corresponding to a cure rate of 68% on per protocol analysis, and 62.96% according to intention to treat analysis. Recurrence of lesion was only occurred in one patient (3.70%). Nausea was the most subjective complication during the therapy (33.33%).

Conclusion

Oral miltefosine could be an effective alternative for the treatment of MA-resistant ACL.

Leishmaniasis is endemic in 98 countries, mainly the Middle Eastern countries including Iran. More than 20 causative species of leishmania are known resulting in diverse disease manifestations, ranging from cutaneous localized ulcers to visceral leishmaniasis that can be fatal. Cutaneous leishmaniasis is usually a localized and self-limited disease, however, chronic non-healing lesions are one of challenging issues. Cutaneous leishmaniasis in Iran is mainly cause by two species: L. major-which causes anthroponotic cutaneous leishmaniasis (ACL)- and L.tropica-which causes zoonotic cutaneous leishmaniasis (ZCL)-. Conventionally, meglumine antimoniate (MA) is administered as standard treatment for ACL. However, resistant forms of ACL to MA are increasingly recognized in endemic areas. Antileishmanial drug miltefosine is capable of immunomodulation and evokes host immune responses. Therapeutic effects of oral miltefosine has been previously confirmed for treatment of visceral and muco-cutaneous leishmanisis. In the current study, oral miltefosine (∼2.5 mg/kg daily) was administered by 27 patients (42 lesions) with MA resistant ACL lesions. After 6-month follow-up, 68% of patients were definitely cured. Therefore, oral miltefosine could be an effective treatment choice for MA resistant ACL.

Leishmaniasis Beyond East Africa

Climate change is having a substantial impact on our environment and ecosystems and has altered the way humans live, access, and utilize resources with increased risk of zoonotic infectious disease encounters. As global temperatures continue to increase, they impact on public health, migration, food security and land conflict, and as new environments become favorable, exposure to disease carrying vectors. Increased forests or natural habitat clearance for land repurposing, urbanization, road building, and water management are related to an increase in emerging vector borne parasitic diseases. The East African region remains one of the most impacted regions globally for leishmaniasis, a vector borne disease that impacts significantly on the health, wellbeing and livelihoods of affected communities and for which a lack of reporting and control interventions hinder progress toward elimination of this neglected tropical disease. As our world continues to transform, both politically and climatically, it is essential that measures are put in place to improve surveillance and disease management with implementation of control measures, including vector control, especially in low- and middle-income countries that are expected to be most impacted by changes in climate. Only through effective management, now, can we be sufficiently resilient to preventing the inevitable spread of vectors into suitable habitat and expansion of the geographical range of leishmaniasis. This review offers a current perspective on Leishmaniasis as an endemic disease in East Africa and examines the potential of the recent emergence of Leishmania infection in hitherto unaffected regions to become a public health concern if no disease management is achieved.

In vitro Antileishmanial Activity of Some Ethiopian Medicinal Plants

Introduction

Leishmaniasis is a group of diseases caused by protozoan parasites, which remains a burden for developing countries. The lack of a vaccine as well as the emergence of resistance toward the recommended drugs pose a challenge for the control of the disease. This urges the demand for new antileishmanial agents to prevent and treat this disease. Consequently, four Ethiopian plants were selected and tested for their antileishmanial activity against two Leishmanial parasites.

Methods

Methanol (80%) was used to macerate the plant materials. In vitro antipromastigote activity of the crude extracts was then tested against promastigotes and axenically cultured amastigotes of Leishmania aethiopica and Leishmania donovani clinical isolates using Alamar Blue assay, and cell viability was measured fluorometrically. 1% DMSO and the media were used as a negative control while amphotericin B was used as a positive control. Furthermore, preliminary phytochemical analysis of the extracts was performed.

Results

From the four plants’ extracts, Ferula communis and Otostegia integrifolia showed better activity with IC₅₀ value of 11.38±0.55 and 13.03±0.87 µg/mL against L. aethiopica, respectively. However, the same plant extracts exhibited lower activity against L. donovani with IC₅₀ values of 23.41±2.32 and 17.24±1.29 µg/mL, respectively. O. integrifolia exhibited highest effect against amastigotes of L. aethiopica (IC₅₀: 16.84±0.65) and L. donovani (IC₅₀:14.55±0.38). F. communis resulted second highest in growth inhibition against amastigotes of L. aethiopica and L. donovani with IC₅₀ value of 14.32±0.54 and 31.12±0.19, respectively. The phytochemical analysis of the extracts indicated the presence of phenol, flavonoids, tannins, saponins, terpenoids, and alkaloids.

Conclusion

The findings from this study demonstrate that crude extracts of F. communis and O. integrifolia showed promising antileishmanial activity against L. aethiopica and L. donovani that may be attributed to the presence of different secondary metabolites.

Challenges and Opportunities for Drug Discovery in Developing Countries: The Example of Cutaneous Leishmaniasis

The current drug discovery paradigm has failed to address the treatment need for diseases of high priority to developing countries. Cutaneous leishmaniasis is a good example of such diseases with virtually no new effective drug developed in the past 70 years. The past two decades had witnessed relatively increased attention toward neglected diseases by stimulating pharmaceutical industries through introductions of Priority Review Vouchers (PRVs) and Product Development Partnerships (PDPs). However, the lion's share of resources allocated for research and development by PRVs and PDPs is directed toward research organizations and pharmaceutical industries in developed countries. This new approach has also not led to the development of drugs for most neglected diseases including cutaneous leishmaniasis. Improving the medical discovery capacity of countries where these diseases are prevalent and enabling exploration of the hitherto untapped natural resources are an effective and sustainable solution.

Prevalence and Risk Factors of Human Leishmaniasis in Ethiopia: A Systematic Review and Meta-Analysis

Introduction

Tropical diseases are public health problems affecting hundreds of millions of people globally. However, the development of adequate, affordable, and accessible treatments is mostly neglected, resulting in significant morbidity and mortality that could otherwise be averted. Leishmaniasis is one of the neglected tropical diseases caused by the obligate intracellular protozoan Leishmania parasite and transmitted by the bite of infected phlebotomine sandflies. No systematic review and meta-analysis has been done to identify the prevalence and risk factors of leishmaniasis to the authors’ knowledge. Therefore, the objective was to determine the prevalence and risk factors of human leishmaniasis in Ethiopia.

Methods

Eleven studies conducted in all regions of Ethiopia, which were fully accessible, written in any language, and original articles done on prevalence and risk factors of leishmaniasis, were included. STATA™ version 11.1 was used for statistical analysis. Chi-square, I², and p values were assessed to check heterogeneity. A random effects model with heterogeneity taken from an inverse-variance model was employed to estimate the pooled effect. Subgroup meta-analysis was computed to reduce random variations among each article’s point prevalence, and Egger and funnel plots were used to check for publication bias.

Results

The highest proportion of human leishmaniasis was reported from a study done in Amhara region (39.1%), and the lowest was reported from a survey done in Tigray (2.3%). The overall pooled prevalence of leishmaniasis was 9.13% (95% CI 5–13.27). Subgroup analysis by region revealed moderate heterogeneity (I² = 51.8%) in studies conducted in the Southern Nations Nationalities and Peoples Region (SNNPR). The presence of hyraxes and being male were associated with an increased risk of human leishmaniasis.

Conclusion

The prevalence of leishmaniasis in Ethiopia remains high (9.13%), with significant risk factors being male and the presence of hyraxes within a 300-m radius of the sleeping area.

Efficacy and Tolerability of Miltefosine in the Treatment of Cutaneous Leishmaniasis

BACKGROUND

Cutaneous leishmaniasis (CL) is a neglected tropical disease causing an estimated 1 million new cases annually. While antimonial compounds are the standard of care worldwide, they are associated with significant adverse effects. Miltefosine, an oral medication, is United States (US) Food and Drug Administration approved to treat CL caused by Leishmania braziliensis, Leishmania guyanensis, and Leishmania panamensis. Evidence of efficacy in other species and side-effect profiles in CL has been limited.

METHODS

Twenty-six patients with CL were treated with miltefosine at the US National Institutes of Health. Species included L. braziliensis (n = 7), L. panamensis (n = 5), Leishmania mexicana (n = 1), Leishmania infantum (n = 3), Leishmania aethiopica (n = 4), Leishmania tropica (n = 2), Leishmania major (n = 1), and unspeciated (n = 3). Demographic and clinic characteristics of the participants, response to treatment, and associated adverse events were analyzed.

RESULTS

Treatment with miltefosine resulted in cure in 77 % (20/26) of cases, with cures among all species. Common adverse events included nausea/vomiting (97%) and lack of appetite (54%). Clinical management or dose reduction was required in a third of cases. Gout occurred in 3 individuals with a prior history of gout. Most laboratory abnormalities, including elevated creatinine and aminotransferases, were mild and normalized after treatment.

CONCLUSIONS

Our data suggest that miltefosine has good but imperfect efficacy to a wide variety of Leishmania species. While side effects were common and mostly mild to moderate, some resulted in discontinuation of therapy. Due to oral administration, broad efficacy, and manageable toxicities, miltefosine is a viable alternative treatment option for CL, though cost and lack of local availability may limit its widespread use.

Enhanced production of pro-inflammatory cytokines and chemokines in Ethiopian cutaneous leishmaniasis upon exposure to Leishmania aethiopica

The clinical course and outcome of cutaneous leishmaniasis (CL) vary due to the infecting Leishmania species and host genetic makeup that result in different immune responses against the parasites. The host immune response to Leishmania aethiopica (L.aethiopica), the causative agent of CL in Ethiopia, is poorly understood. To contribute to the understanding of the protective immune response in CL due to L.aethiopica, we characterized the cytokine response to L. aethiopica in patients with the localized form of CL (LCL) and age-and sex-matched apparently healthy controls. By applying a whole blood based in vitro culture we found enhanced release of TNF, IL-6, MCP-1 or CCL2, IP-10 or CXCL10, MIP-1β or CCL4 and IL-8 or CXCL8- but not of IL-10CL patients in response to L. aethiopica compared to the controls. No difference was observed between LCL cases and controls in the secretion of these cytokines and chemokines in whole blood cultures treated with the TLR-ligands LPS, MALP-2 or polyI: C. The observed increased secretion of the pro-inflammatory cytokines/chemokines reflects an enhanced response against the parasites by LCL patients as compared to healthy controls rather than a generally enhanced ability of blood leukocytes from LCL patients to respond to microbial constituents. Our findings suggest that the enhanced production of pro-inflammatory cytokines/chemokines is associated with localized cutaneous leishmaniasis caused by L.aethiopica.

Overview of herbal and traditional remedies in the treatment of cutaneous leishmaniasis based on Traditional Persian Medicine

This study aims to describe the herbal and traditional remedies in the treatment of cutaneous leishmaniasis (CL) with an overview on related available evidence in modern medicine. This study is a review that focuses on the most important Traditional Persian Medicine (TPM) sources including Avicenna's Canon of Medicine, Jorjani's Zakhīra-yi Khārazmshāhī, and Aazam-Khan's Eksir-e-Aazam, as well as pertinent information from Embase, PubMed, Scopus, Scientific Information Database, and Google Scholar by using the keywords salak, rīsh-e-balkhi, cutaneous leishmaniasis, and leishmaniasis for selected remedies. Several oral and topical herbal remedies, such as Vitis vinifera L. (Unripe grapes), Berberis vulgaris L., Rheum ribes L., Santalum album L., Cinnamomum camphora (L.) J.Presl (Camphor), Brassica nigra (L.) K. Koch, Crocus sativus L., Juniperus excelsa M. Bieb, honey, and Alum root, were mentioned in TPM resources for the treatment of CL. Furthermore, cauterization, cupping, and leech therapy were considered for this purpose. In this review, some evidence-based studies will also be presented that have demonstrated the therapeutic properties of some of these products. In conclusion, the sages of TPM have recommended several systemic or topical medications, in addition to physical procedures, for treatment of CL, all of which could be a base for conducting further research on its efficacy.

Relapsing cutaneous leishmaniasis in a patient requiring TNF-α-inhibitor Infliximab for Takayasu-arteritis: Case report and review of the literature

Leishmaniasis is a protozoan parasitic infection that can manifest as visceral or cutaneous disease. Immunosuppression, mainly through TNF-α) inhibition, is a risk factor for complicated leishmaniasis that is becoming increasingly known. Here, we present a case of cutaneous leishmaniasis (CL) in a patient who suffers from advanced Takayasu-Arteritis, requiring TNF-α inhibition with infliximab. The primary CL lesions in this 47-year-old, female patient were caused by Leishmaniapanamensis and occurred after a touristic trip to Panama on her right foot. The lesions first resolved under treatment with liposomal amphotericin B. However, ten months later, the patient returned with relapsing lesions requiring further treatment. We discuss the challenges and risks of leishmaniasis in patients with TNF-α inhibition and the rare phenomenon of relapsing CL and the management hereof. We review published cases of CL associated with TNF-α inhibition. A growing body of evidence now suggests that especially CL (and visceral leishmaniasis (VL)) can be associated with TNF-α inhibition. The host response to leishmaniasis is of the Th1-type and TNF-α and interferon-gamma expression are crucial for disease control. Inversely, TNF-α inhibition can lead to complicated and relapsing progression of leishmanial infection. Therefore, we propose that CL and VL should be considered in at-risk patients receiving immunosuppressants.

The Geographical Distribution of Cutaneous Leishmaniasis Causative Agents in Iran and Its Neighboring Countries, A Review

Leishmania tropica and Leishmania major are both the main cause of anthroponotic (ACL) and zoonotic cutaneous leishmaniasis (ZCL), respectively, in the Old World. Leishmania infantum and Leishmania donovani, which are important causes of visceral leishmaniasis, have also occasionally been reported in CL patients. The present study investigates the current distribution of causative species of CL in Iran and neighboring countries in the Middle East. There has been expansion of L. tropica into new urban and rural foci in Iran, with well-documented cases of visceralization, a substantial increase of CL in Syria, and the emergence of new foci and outbreaks in Turkey and Iraq, especially due to L. major. Civil war in Syria and Iraq, population movement, poverty, and climatic change play important roles in the changing CL distribution in this region. Control programs should adopt a multidisciplinary approach based on active surveillance and case finding, especially in vulnerable refugee populations, determination of hazard maps for CL hot points using GIS and other advanced technology, the free distribution of drugs, rodent control, and greater community engagement in poor and marginalized populations. Comprehensive molecular studies that could show the species and strains of Leishmania in different areas of each country can give a better view from the distribution of CL in this region.

Cutaneous leishmaniasis a neglected tropical disease: community knowledge, attitude and practices in an endemic area, Northwest Ethiopia

Background

Cutaneous leishmaniasis is one of the neglected tropical diseases in the Ethiopian highlands and studies on assessment of knowledge, attitude and practice of the community in endemic areas are scanty. The study aimed to assess the knowledge, attitude towards cutaneous leishmaniasis and treatment seeking practices in people living in the endemic highlands areas in the Northwest, Ethiopia and to provide evidence-based information to guide development of appropriate interventions to reduce the impact of cutaneous leishmaniasis on communities.

Methods

Quantitative cross-sectional study was conducted in cutaneous leishmaniasis endemic districts (woredas) using a semi structured questionnaire. Households were randomly selected according to probability proportional to size of households in each enumeration area. Systematic random sampling of eligible households was based on the number of households recorded during listing of households. Descriptive statistics was used to describe numerical data, organise and summarise the data in a manner that gave meaning to the numerical form. Frequency tables were used to show descriptive analysis and regression analysis was used to determine correlation between variables.

Results

Majority of respondents 321(78.7%) lived in rural areas, age ranged between 18 and 85 years and most were farmers. Illiteracy was high (47.6%) among respondents and majority 358(87.8%) had seen patients with CL. Less than quarter (21.6%) had heard about sand flies and knowledge on the peak transmission period was low (46.3%). About 192 (47.1%) of the respondents indicated disfiguring lesions were the major clinical presentations, less than half 55(27.5%) of urban residents believed CL was treatable compared to 145(72.5%) of rural residents (P < 0.001). Traditional medicines were indicated as best treatment option by 209(51.2%) compared to 114(27.9%) for modern treatment. Major factors influencing treatment options included accessibility to treatment facilities, distance and short duration of treatment. Participants expressed negative experiential attitude and perceived control towards modern treatment because of inaccessibility and distance from where modern treatment is provided.

Conclusion

Priority should be given to primary prevention and appropriate awareness campaigns on lesion recognition. Information on modern treatment should be intensified.

Leishmania Vaccines Entered in Clinical Trials: A Review of Literature

Leishmaniasis is considered as a zoonotic infection and neglected tropical disease. Leishmania treatment is not totally successful and imposes high expenditures, especially in developing countries. Since the natural infection leads to the robust immunity in most of the human cases, many bodies of research have been focusing on Leishmania vaccines, being capable to control Leishmania infection. First generation vaccines (such as Leishmune^® and CaniLeish^®) have proved robust protective immunity in dogs. In human, recombinant vaccines, including Leish-F1 could confer some degrees of protective immunity against natural infection. Recently, ChAd63-KH DNA vaccine has been accomplished in providing prevention against Leishmania infection; however, this vaccine should be further evaluated in other clinical trials.

Draft Genome Sequences of Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) mexicana, and Leishmania (Leishmania) aethiopica, Potential Etiological Agents of Diffuse Cutaneous Leishmaniasis

We present here the draft genome sequences of Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) mexicana, and Leishmania (Leishmania) aethiopica, potential etiological agents of diffuse cutaneous leishmaniasis (DCL). Sequence data were obtained using PacBio and MiSeq platforms.

We present here the draft genome sequences of Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) mexicana, and Leishmania (Leishmania) aethiopica, potential etiological agents of diffuse cutaneous leishmaniasis (DCL). Sequence data were obtained using PacBio and MiSeq platforms. The PacBio assemblies generated using Canu v1.6 are more contiguous than are those in the available data.

Evaluation of microcapillary culture method for the isolation of Leishmania aethiopica parasites from patients with cutaneous lesions in Ethiopia

BACKGROUND

In addition to direct slide microscopy, traditional culture method (TCM) has long been considered as a gold standard method for the diagnosis of cutaneous leishmaniasis (CL). However, TCM is relatively expensive and time-consuming compared to the newly introduced microculture method (MCM), which has shown to be sensitive and rapid diagnostic method elsewhere for different Leishmania parasite species other than Leishmania (L.) aethiopica. The objective of this study was to evaluate the diagnostic performance of MCM for the diagnosis of CL caused by L. aethiopica.

METHODS

One hundred forty-three lesion aspirates were collected from 124 suspected CL patients prospectively based on their consecutive series. Portion of the aspirates were cultured in duplicate in TCM with modified Novy-MacNeal-Nicolle (NNN) in tissue culture flask and microcapillary tubes containing RPMI 1640 with 10% fetal bovine serum (FBS) for MCM. Smears on glass slides from the remaining portion of the aspirate were used for direct microscopy to detect the parasite after stained with Giemsa staining solution. Up on a consensus, positive result in any two of the three tests was used as a reference standard to analyze sensitivity.

RESULTS

As per consensus standard criteria, 52 of the lesions were qualified to evaluate MCM versus TCM. Forty-eight lesion samples were positive by MCM, 36 by TCM, and 37 by smear microscopy. The representative DNA from parasite culture isolates revealed the causative Leishmania parasite was L. aethiopica by ITS1 polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Culturing L. aethiopica in vitro by MCM is more sensitive (92.3%) than by TCM (69.2%), P = 0.003. The median time for L. aethiopica promastigotes emergence in the culture was 3 days for MCM and 6 days for TCM, P < 0.001.

CONCLUSIONS

Our finding indicated that MCM is a sensitive and a rapid culturing method for the isolation of L. aethiopica than TCM and smear microscopy.

Understanding the economic impact of leishmaniasis on households in endemic countries: a systematic review

INTRODUCTION

Leishmaniasis is a poverty-related disease that causes a significant socioeconomic burden to affected households. Visceral leishmaniasis is fatal if untreated, yet illness costs may lead to delays in accessing care. Skin manifestations of leishmaniasis cause a psychological burden and even longer treatment trajectories. The objective of this review is to evaluate illness costs associated with leishmaniasis across different settings (Asia, Africa, and Latin America) and the consequences to households. Areas covered: Through a systematic review of cost-of-illness studies, we documented the distribution of costs, the health-seeking behavior, and the consequences of leishmaniasis. We discuss the value of cost-of-illness studies for leishmaniasis. Expert commentary: Despite the free provision of diagnostics and treatment in the public health care sector, out-of-pocket payments remain substantial. There has been progress in addressing the economic burden of leishmaniasis, particularly through the elimination initiative in the Indian subcontinent. Though the illness cost is decreasing due to shorter treatment regimens and better access to care, the situation remains challenging in Africa. Improvement of control tools is critical. There is a need to update cost estimates to inform policy-making and ensure sustainable solutions to reduce financial barriers to leishmaniasis care, especially in pursuing universal health coverage.

Cutaneous Leishmaniasis Due to Leishmania aethiopica

Leishmania aethiopica is the main causative species for cutaneous leishmaniasis (CL) in Ethiopia. Despite its considerable burden, L. aethiopica has been one of the most neglected Leishmania species. In this review, published evidence on L. aethiopica history, geography, vector, reservoir, epidemiology, parasitology, and immunology is discussed and knowledge gaps are outlined. L. aethiopica endemic regions are limited to the highland areas, although nationwide studies on CL prevalence are lacking. Phlebotomus pedifer and P. longipes are the sandfly vectors and hyraxes are considered to be the main reservoir, but the role of other sandfly species and other potential reservoirs requires further investigation. Where and how transmission occurs exactly are also still unknown. Most CL patients in Ethiopia are children and young adults. Lesions are most commonly on the face, in contrast to CL caused by other Leishmania species which may more frequently affect other body parts. CL lesions caused by L. aethiopica seem atypical and more severe in their presentation as compared to other Leishmania species. Mucocutaneous leishmaniasis and diffuse cutaneous leishmaniasis are relatively common, and healing of lesions caused by L. aethiopica seems to take longer than that of other species. A thorough documentation of the natural evolution of L. aethiopica as well as in depth studies into the immunological and parasitological characteristics that underpin the atypical and severe clinical presentation are needed. Better understanding of CL caused by this parasite species will contribute to interventions related to transmission, prevention, and treatment.

Comportamiento epidemiológico, distribución geográfica y manejo clínico inicial de la leishmaniasis cutánea en Boyacá. 2008-2015

Introduction: Leishmaniasis is a reemerging disease that causes more sequelae and disability than any other of its kind in areas where geographical conditions favor the presence of the vector.Objective: To describe the behavior, geographical distribution and initial clinical management of cutaneous leishmaniasis in the department of Boyacá between 2008 and 2015.Materials and methods: Observational, retrospective study on a sample of patients diagnosed with cutaneous leishmaniasis in the department of Boyacá, Colombia, registered in the mandatory epidemiological notification sheets of the Colombian public health surveillance system from 2008 to 2015.Results: 63.6% of patients were men with occupations related to forestry activities and from rural areas. 81% of the reported cases were located in western Boyacá, along the Magdalena River basin, one of the main tributaries of Colombia. Inadequate initial clinical management was observed in 25% of the study sample, which is a risk factor for resistance to pentavalent antimonials.Conclusion: It is necessary to implement follow-up strategies for patients with cutaneous leishmaniasis in order to verify the cure criteria for the disease and propose strategies for its prevention in the identified populations that are at greater risk.

Comparing the therapeutic efficacy of different amphotericin B-carrying delivery systems against visceral leishmaniasis

Amphotericin B (Amp) has been well-successfully used to treat against Leishmania infection, although high toxicity has been found in patients. In the present study, Amp was administered in Leishmania infantum-infected BALB/c mice by three distinct delivery systems aiming to compare their efficacy against challenge infection, as well as their side effects in a murine visceral leishmaniasis (VL) model. This product was administered in a Poloxamer P407 (Pluronic^® F127)-based polymeric micelle system (Amp/M), in the Ambisome^® formulation (Lip-Amp) or in a free format (free Amp). Glucantime^® (Gluc) was used as a comparative drug. Aiming to evaluate different endpoints of the treatments, the efficacy of the compounds was investigated one and 15-days after the therapeutic regimens, determining the parasite load by a limiting dilution assay and a quantitative PCR (qPCR) technique, as well as evaluating the immune response generated in the infected and treated animals. In the results, Amp/M or Lip-Amp-treated mice presented the best outcomes, since significant parasite load reductions were found in the evaluated organs, as well as a parasite-specific Th1 immune response was observed in the animals. In addition, no hepatic or renal damage was found in these mice. On the other hand, free Amp or Gluc induced toxicity in the animals, which was associated with a low Th1 immune response. Comparatively, Amp/M was the most effective drug in our experimental model, and results showed that the Amp-carrying system could be considered as a future alternative in studies against VL.

Drug resistance and treatment failure in leishmaniasis: A 21st century challenge

Reevaluation of treatment guidelines for Old and New World leishmaniasis is urgently needed on a global basis because treatment failure is an increasing problem. Drug resistance is a fundamental determinant of treatment failure, although other factors also contribute to this phenomenon, including the global HIV/AIDS epidemic with its accompanying impact on the immune system. Pentavalent antimonials have been used successfully worldwide for the treatment of leishmaniasis since the first half of the 20th century, but the last 10 to 20 years have witnessed an increase in clinical resistance, e.g., in North Bihar in India. In this review, we discuss the meaning of “resistance” related to leishmaniasis and discuss its molecular epidemiology, particularly for Leishmania donovani that causes visceral leishmaniasis. We also discuss how resistance can affect drug combination therapies. Molecular mechanisms known to contribute to resistance to antimonials, amphotericin B, and miltefosine are also outlined.

Chemotherapy is central to the control and management of leishmaniasis. Antimonials remain the primary drugs against different forms of leishmaniasis in several regions. However, resistance to antimony has necessitated the use of alternative medications, especially in the Indian subcontinent (ISC). Compounds, notably the orally available miltefosine (MIL), parenteral paromomycin, and amphotericin B (AmB), are increasingly used to treat leishmaniasis. Although treatment failure (TF) has been observed in patients treated with most anti-leishmanials, its frequency of appearance may be important in patients treated with MIL, which has replaced antimonials within the kala-azar elimination program in the ISC. AmB is highly efficacious, and the associated toxic effects—when administered in its free deoxycholate form—are somewhat ameliorated in its liposomal formulation. Regrettably, laboratory experimentation has demonstrated a risk of resistance towards AmB as well. The rise of drug resistance impacts treatment outcome, and understanding its causes, spread, and impact will help us manage the risks it imposes. Here, we review the problem of TF in leishmaniasis and the contribution of drug resistance to the problem. Molecular mechanisms causing resistance to anti-leishmanials are discussed along with the appropriate use of additional available drugs, as well as the urgent need to consolidate strategies to monitor drug efficacy, epidemiological surveillance, and local policies. Coordination of these activities in national and international programs against leishmaniasis might represent a successful guide to further research and prevention activities.

Synthetic analogs of an Entamoeba histolytica glycolipid designed to combat intracellular Leishmania infection

Intracellular pathogens belonging to the genus Leishmania have developed effective strategies that enable them to survive within host immune cells. Immunostimulatory compounds that counteract such immunological escape mechanisms represent promising treatment options for diseases. Here, we demonstrate that a lipopeptidephosphoglycan (LPPG) isolated from the membrane of a protozoan parasite, Entamoeba histolytica (Eh), shows considerable immunostimulatory effects targeted against Leishmania (L.) major, a representative species responsible for cutaneous leishmaniasis (CL). Treatment led to a marked reduction in the number of intracellular Leishmania parasites in vitro, and ameliorated CL in a mouse model. We next designed and synthesized analogs of the phosphatidylinositol anchors harbored by EhLPPG; two of these analogs reproduced the anti-leishmanial activity of the native compound by inducing production of pro-inflammatory cytokines. The use of such compounds, either alone or as a supportive option, might improve the currently unsatisfactory treatment of CL and other diseases caused by pathogen-manipulated immune responses.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cutaneous Manifestations of Human and Murine Leishmaniasis

The leishmaniases are diseases caused by pathogenic protozoan parasites of the genus Leishmania. Infections are initiated when a sand fly vector inoculates Leishmania parasites into the skin of a mammalian host. Leishmania causes a spectrum of inflammatory cutaneous disease manifestations. The type of cutaneous pathology is determined in part by the infecting Leishmania species, but also by a combination of inflammatory and anti-inflammatory host immune response factors resulting in different clinical outcomes. This review discusses the distinct cutaneous syndromes described in humans, and current knowledge of the inflammatory responses associated with divergent cutaneous pathologic responses to different Leishmania species. The contribution of key hematopoietic cells in experimental cutaneous leishmaniasis in mouse models are also reviewed and compared with those observed during human infection. We hypothesize that local skin events influence the ensuing adaptive immune response to Leishmania spp. infections, and that the balance between inflammatory and regulatory factors induced by infection are critical for determining cutaneous pathology and outcome of infection.