Leishmaniasis cutánea resistente al antimoniato de meglumina intramuscular / Resistance to Intramuscular Meglumine Antimoniate in Cutaneous Leishmaniasis

La leishmaniasis es una enfermedad causada por pará- sitos protozoarios del género Leishmania. Se clasifica como: cutánea, mucocutánea y visceral. De las ante- riores, la Leishmaniasis cutánea (LC) es la forma más común a nivel mundial, transmitida a humanos por la picadura del mosquito hembra, el cual pertenece a la familia Phlebotominae y Lutzomyia. La cutánea gene- ralmente se manifiesta clínicamente por presentar una pápula ulcerada con exudado seroso, con fondo limpio de aspecto granular y bordes hiperémicos y engrosados. Presentamos el caso de un adolescente de 16 años de edad, procedente de Aldea Peña Blanca Norte, San Pe- dro Sula, con lesión eritemato-costrosa, tumefacta no dolorosa de 2 meses de evolución, en pabellón auri- cular derecho. El paciente fue visto en consulta exter- na de Dermatología Pediátrica del Instituto Hondure- ño de Seguridad Social Regional del Norte (I.H.S.S.), recibiendo tratamiento con antibióticos sistémicos y tópicos (trimetoprim sulfametoxazol, mupirocina un- güento), por 7 días. Previamente había recibido varios tratamientos sistémicos orales y parenterales (amoxici- lina/ ácido clavulánico, dicloxacilina, penicilina benza- tínica, y aplicación tópica de ácido fusídico) sin obtener mejoría clínica alguna; se le envió a realizar microsco- pía directa con tinción de Giemsa de frotis obtenido de la lesión en el Centro de Salud "Miguel Paz Barahona", demostrando la presencia de amastigotes. Se inició al antimoniato de meglumina según esquema estableci- do por la Organización Mundial de la Salud (OMS) a razón de 20 mg/kg/día intramuscular por 30 días. Debido a la falla de tratamiento se deci- de utilizar itraconazol durante 3 meses con buena respuesta y sin efectos adversos...(AU)

ASSESSMENT OF THE OXIDATIVE AND NITROSATIVE STRESS IN THE SERUM OF SAUDI PATIENTS WITH CUTANEOUS LEISHMANIASIS BEFORE AND AFTER TREATMENT.

Macrophages, within which Leishmania species replicate, generate large amounts of reactive oxygen species (ROS) and reactive nitrogen species (RNS) to kill these parasites. The present study assessed the oxidative and nitrosative stress, and specific immune enzymes in the serum of patients with cutaneous leishmaniasis (Cl) before and after treatment and in the control individuals. Serum activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), L-arginase, myeloperoxidase (MPO), and adenosine deaminase (ADA) and the levels of reduced glutathione, malondialdehyde (MDA), and nitric oxide (NO) were studied. The activities of L-arginase, MPO, and ADA and the levels of MDA and NO were significantly elevated (P < 0.001), while the activities of SOD, CAT, and GSH-Px, and the levels of reduced glutathione (GSH) were significantly (P < 0.001) reduced in untreated patients as compared with values of patients after treatment and of control individuals. The treatment, which included intramuscular injection of sodium stibogluconate and meglumine antimoniate, ameliorated these factors in comparison to the untreated group. These results suggest that oxidative and nitrosative stress may play an important role in the pathogenesis of untreated cutaneous leishmaniasis. Furthermore, the reduction in oxidative and nitrosative stress in the treated Cl patients may be due to the drug decreasing energy production by the parasite, which eventually leads to its death.

Estimating direct costs of the treatment for mucosal leishmaniasis in Brazil.

INTRODUCTION: The objective of this study was to estimate the direct medical costs of the treatment for mucosal leishmaniasis (ML) using three therapeutic approaches in the Brazilian context. METHODS: We performed this economic assessment from the perspective of the Brazilian public healthcare system. The following therapeutic approaches were evaluated: meglumine antimoniate, liposomal amphotericin B, and miltefosine. Direct medical costs were estimated considering four treatment components: a) drug, b) combined medical products, c) procedures, and d) complementary tests. RESULTS: Treatment with meglumine antimoniate had the lowest average cost per patient (US$ 167.66), followed by miltefosine (US$ 259.92) in the outpatient treatment regimen. The average cost of treatment with liposomal amphotericin B was US$ 715.35 both in inpatient regimen. In all estimates, the drugs accounted for more than 60% of the total cost for each treatment approach. CONCLUSIONS: These results demonstrate the marked differences in costs between the therapeutic alternatives for ML. In addition to efficacy rates and costs related to adverse events, our data have the potential to support a complete cost-effectiveness study in the future. Complete analyses comparing costs and benefits for interventions will assist health managers in choosing drugs for ML treatment in Brazil as well as in establishing effective public health policies.

Estimating direct costs of the treatment for mucosal leishmaniasis in Brazil

Abstract INTRODUCTION: The objective of this study was to estimate the direct medical costs of the treatment for mucosal leishmaniasis (ML) using three therapeutic approaches in the Brazilian context. METHODS: We performed this economic assessment from the perspective of the Brazilian public healthcare system. The following therapeutic approaches were evaluated: meglumine antimoniate, liposomal amphotericin B, and miltefosine. Direct medical costs were estimated considering four treatment components: a) drug, b) combined medical products, c) procedures, and d) complementary tests. RESULTS: Treatment with meglumine antimoniate had the lowest average cost per patient (US$ 167.66), followed by miltefosine (US$ 259.92) in the outpatient treatment regimen. The average cost of treatment with liposomal amphotericin B was US$ 715.35 both in inpatient regimen. In all estimates, the drugs accounted for more than 60% of the total cost for each treatment approach. CONCLUSIONS: These results demonstrate the marked differences in costs between the therapeutic alternatives for ML. In addition to efficacy rates and costs related to adverse events, our data have the potential to support a complete cost-effectiveness study in the future. Complete analyses comparing costs and benefits for interventions will assist health managers in choosing drugs for ML treatment in Brazil as well as in establishing effective public health policies.

The potential role of nicotinamide on Leishmania tropica: An assessment of inhibitory effect, cytokines gene expression and arginase profiling.

Leishmaniasis represents a major health concern worldwide which has no effective treatment modality. Nicotinamide (NAm) has been used for a wide range of applications from anticancer to antimicrobial usage. This study aimed to assess the effect of NAm combination on Leishmania tropica Inhibition, as well as on cytokines gene expression and arginase (ARG) activity in L. tropica-infected macrophages in an in vitro model. The leishmanicidal effects of NAm and Glucantime (meglumine antimoniate, MA) alone and in combination (NAm/MA) were evaluated using a colorimetric assay and macrophage model. Additionally, immunomodulatory effects and enzymatic activity were assessed by analyzing Th1 and Th2 cytokines gene expression and ARG level, respectively, in infected macrophages treated with NAm and MA, alone and in combination. Findings indicated that the NAm/MA combination demonstrated greater inhibitory effects on L. tropica promastigotes and amastigotes compared with each drug individually. Docking results proved the affinity of NAm to IFN-γ, which can affirm the increased levels of IFN-γ, IL-12p40 and TNF-α as well as reductions in IL-10 secretion with a dose-response effect, especially in the combination group. The NAm/MA combination also showed a significant reduction in the level of ARG activity at all concentrations used compared to each drug individually. These findings indicate higher effectiveness of NAm plus MA in reducing parasite growth, promoting immune response and inhibiting ARG level. This combination should be considered as a potential therapeutic regimen for treatment of volunteer patients with anthroponotic cutaneous leishmaniasis (ACL) in future control programs.

Intralesional infiltration versus parenteral use of meglumine antimoniate for treatment of cutaneous leishmaniasis: A cost-effectiveness analysis.

Cutaneous leishmaniasis (LC) is a complex and variable disease in terms of epidemiology, aetiology, pathology and clinical characteristics. The mainstay of treatment is still pentavalent antimony (Sbv) compounds administered systemically, despite their recognized toxicity. The advantages of antimony intralesional (IL) infiltration are the use of lower doses of Sbv and, therefore, less toxic effects. The objective of this study was to estimate the cost-effectiveness ratio of intralesional meglumine antimoniate therapy (IL-MA) compared with endovenous meglumine antimoniate therapy (EV-MA) for the treatment of CL in the context of the Brazilian National Health System (SUS). An analytical decision model (decision tree) was developed using TreeAge Pro 2018 software. Data from the open-label, uncontrolled phase II clinical trial evaluating IL-MA were used as a reference for posology, efficacy, and adverse event rates (AE). The same premises for the intravenous approach (EV-MA) were extracted from systematic literature reviews. Macro and micro calculations of spending were included in the analysis. The IL-MA and EV-MA strategies had a total cost per patient cured of US$330.81 and US$494.16, respectively. The intralesional approach was dominant, meaning it was more economic and effective than was endovenous therapy. The incremental cost-effectiveness ratio showed that IL-MA could result in savings of US$864.37 for each additional patient cured, confirming that the IL-MA strategy is cost effective in the context of the Brazilian public health scenario.

"Cheaper and better": Societal cost savings and budget impact of changing from systemic to intralesional pentavalent antimonials as the first-line treatment for cutaneous leishmaniasis in Bolivia.

INTRODUCTION: Cutaneous leishmaniasis (CL), endemic in Bolivia, mostly affects poor people in rainforest areas. The current first-line treatment consists of systemic pentavalent antimonials (SPA) for 20 days and is paid for by the Ministry of Health (MoH). Long periods of drug shortages and a lack of safe conditions to deliver treatment are challenges to implementation. Intralesional pentavalent antimonials (ILPA) are an alternative to SPA. This study aims to compare the cost of ILPA and SPA, and to estimate the health and economic impacts of changing the first-line treatment for CL in a Bolivian endemic area. METHODS: The cost-per-patient treated was estimated for SPA and ILPA from the perspectives of the MoH and society. The quantity and unit costs of medications, staff time, transportation and loss of production were obtained through a health facility survey (N = 12), official documents and key informants. A one-way sensitivity analysis was conducted on key parameters to evaluate the robustness of the results. The annual number of patients treated and the budget impact of switching to ILPA as the first-line treatment were estimated under different scenarios of increasing treatment utilization. Costs were reported in 2017 international dollars (1 INT$ = 3.10 BOB). RESULTS: Treating CL using ILPA was associated with a cost-saving of $248 per-patient-treated from the MoH perspective, and $688 per-patient-treated from the societal perspective. Switching first-line treatment to ILPA while maintaining the current budget would allow two-and-a-half times the current number of patients to be treated. ILPA remained cost-saving compared to SPA in the sensitivity analysis. CONCLUSIONS: The results of this study support a shift to ILPA as the first-line treatment for CL in Bolivia and possibly in other South American countries.

Treatment for human visceral leishmaniasis: a cost-effectiveness analysis for Brazil.

OBJECTIVE: To estimate the cost-effectiveness of strategies for the treatment of VL in Brazil. METHODS: Cost-effectiveness study comparing three therapeutic options: meglumine antimoniate (MA), liposomal amphotericin B (LAMB) and a combination of LAMB plus MA (LAMB plus MA), from public health system and societal perspectives. An analytical decision-making model was used to compare strategies for the following outcomes: early therapeutic failure avoided at 30 days, days of hospitalisation avoided and VL cure at 180 days. The efficacy and safety parameters of the drugs came from a randomised, open-label trial and the cost data came from a cost-of-illness study, both carried out in Brazil. RESULTS: For all outcomes analysed, the LAMB strategy was more effective. The MA strategy was inferior to the LAMB plus MA strategy for the outcomes early therapeutic failure avoided and cure. When only LAMB and MA were compared from a societal perspective, a cost of US$ 278.56 was estimated for each additional early therapeutic failure avoided, a cost of US$ 26.88 for each additional day of hospitalisation avoided and a cost of US$ 89.88 for each additional case of cured VL, for the LAMB strategy vs. MA. CONCLUSION: In Brazil, the LAMB strategy proved to be cost-effective for treating VL, considering a GDP per capita as the willingness-to-pay threshold, for all of the outcomes analysed in comparison to MA.

OBJECTIF: Estimer la rentabilité des stratégies de traitement de la leishmaniose viscérale (LV) au Brésil. MÉTHODES: Etude coût-efficacité comparant trois options thérapeutiques: l'antimoniate de méglumine (AM), amphotéricine B liposomale (LAMB) et une combinaison de LAMB et MA (LAMB plus AM), du point de vue du système de santé publique et sociétal. Un modèle décisionnel analytique a été utilisé pour comparer les stratégies pour les résultats suivants: échec thérapeutique précoce évité à 30 jours, jours d'hospitalisation évités et guérison de la LV à 180 jours. Les paramètres d'efficacité et de sécurité des médicaments provenaient d'un essai randomisé ouvert et les données relatives aux coûts, d'une étude sur le coût de la maladie, toutes deux menées au Brésil. RÉSULTATS: Pour tous les résultats analysés, la stratégie LAMB était plus efficace. La stratégie AM était inférieure à la stratégie LAMB plus AM pour les résultats: échec thérapeutique précoce évité et guérison. Lorsque seules les stratégies LAMB et AM ont été comparées d'un point de vue sociétal, un coût de 278,56 USD a été estimé pour chaque échec thérapeutique précoce additionnel évité, un coût de 26,88 USD pour chaque jour d'hospitalisation additionnel évité et un coût de 89,88 USD pour chaque cas additionnel de LV guéri, pour la stratégie LAMB par rapport à AM. CONCLUSION: Au Brésil, la stratégie LAMB s'est avérée rentable pour traiter la LV, considérant un PIB par habitant comme seuil de volonté de payer, pour tous les résultats analysés par rapport à l'AM.

Comprehensive economic evaluation of thermotherapy for the treatment of cutaneous leishmaniasis in Colombia.

BACKGROUND: Cutaneous leishmaniasis causes a high disease burden in Colombia, and available treatments present systemic toxicity, low patient compliance, contraindications, and high costs. The purpose of this study was to estimate the cost-effectiveness of thermotherapy versus Glucantime in patients with cutaneous leishmaniasis in Colombia. METHODS: Cost-effectiveness study from an institutional perspective in 8133 incident cases. Data on therapeutic efficacy and safety were included, calculating standard costs; the outcomes were disability adjusted life years (DALYs) and the number of patients cured. The information sources were the Colombian Public Health Surveillance System, disease burden studies, and one meta-analysis of controlled clinical trials. Incremental cost-effectiveness was determined, and uncertainty was evaluated with tornado diagrams and Monte Carlo simulations. RESULTS: Thermotherapy would generate costs of US$ 501,621; the handling of adverse effects, US$ 29,224; and therapeutic failures, US$ 300,053. For Glucantime, these costs would be US$ 2,731,276, US$ 58,254, and US$ 406,298, respectively. With thermotherapy, the cost would be US$ 2062 per DALY averted and US$ 69 per patient cured; with Glucantime, the cost would be US$ 4241 per DALY averted and US$ 85 per patient cured. In Monte Carlo simulations, thermotherapy was the dominant strategy for DALYs averted in 67.9% of cases and highly cost-effective for patients cured in 72%. CONCLUSION: In Colombia, thermotherapy can be included as a cost-effective strategy for the management of cutaneous leishmaniasis. Its incorporation into clinical practice guidelines could represent savings of approximately US$ 10,488 per DALY averted and costs of US$ 116 per additional patient cured, compared to the use of Glucantime. These findings show the relevance of the incorporation of this treatment in our country and others with similar parasitological, clinical, and epidemiological patterns.

The direct costs of treating human visceral leishmaniasis in Brazil.

INTRODUCTION:: The drugs available for visceral leishmaniasis (VL) treatment in Brazil have specific characteristics in terms of operability, effectiveness, toxicity, and cost. The aim of this study was to estimate the direct costs of therapies recommended by the Ministry of Health (MH) for VL treatment in Brazil. METHODS:: The analytical perspective used was that adopted by the Brazilian Public Health System. Three drugs and four regimens were included: 1) N-methyl glucamine antimoniate intramuscularly at 20mg per kg per day for 30 days; 2) N-methyl glucamine antimoniate intravenously at 20mg per kg per day for 30 days; 3) amphotericin B deoxycholate at 1mg per kg per day for 21 days; and 4) liposomal amphotericin B at 3mg per kg per day for a 7 days treatment. RESULTS:: The estimated direct costs of treatment for an adult patient using N-methylglucamine antimoniate administered via the intramuscular and intravenous routes were USD 418.52 and USD 669.40, respectively. The estimated cost of treatment with amphotericin B deoxycholate was USD 1,522.70. Finally, the estimated costs of treatment with liposomal amphotericin B were USD 659.79, and USD 11,559.15 using the price adopted by the WHO and the Drug Regulation Board, respectively. CONCLUSIONS:: This analysis indicates the economic feasibility of replacing N-methyl glucamine antimoniate with liposomal amphotericin B, which allows a shorter treatment period with less toxicity compared with other treatments, provided that the purchase value used by the WHO and transferred to the MH is maintained.

The direct costs of treating human visceral leishmaniasis in Brazil

Abstract INTRODUCTION: The drugs available for visceral leishmaniasis (VL) treatment in Brazil have specific characteristics in terms of operability, effectiveness, toxicity, and cost. The aim of this study was to estimate the direct costs of therapies recommended by the Ministry of Health (MH) for VL treatment in Brazil. METHODS: The analytical perspective used was that adopted by the Brazilian Public Health System. Three drugs and four regimens were included: 1) N-methyl glucamine antimoniate intramuscularly at 20mg per kg per day for 30 days; 2) N-methyl glucamine antimoniate intravenously at 20mg per kg per day for 30 days; 3) amphotericin B deoxycholate at 1mg per kg per day for 21 days; and 4) liposomal amphotericin B at 3mg per kg per day for a 7 days treatment. RESULTS: The estimated direct costs of treatment for an adult patient using N-methylglucamine antimoniate administered via the intramuscular and intravenous routes were USD 418.52 and USD 669.40, respectively. The estimated cost of treatment with amphotericin B deoxycholate was USD 1,522.70. Finally, the estimated costs of treatment with liposomal amphotericin B were USD 659.79, and USD 11,559.15 using the price adopted by the WHO and the Drug Regulation Board, respectively. CONCLUSIONS: This analysis indicates the economic feasibility of replacing N-methyl glucamine antimoniate with liposomal amphotericin B, which allows a shorter treatment period with less toxicity compared with other treatments, provided that the purchase value used by the WHO and transferred to the MH is maintained.

Cost-effectiveness of meglumine antimoniate versus miltefosine caregiver DOT for the treatment of pediatric cutaneous leishmaniasis.

BACKGROUND: Oral miltefosine has been shown to be non-inferior to first-line, injectable meglumine antimoniate (MA) for the treatment of cutaneous leishmaniasis (CL) in children. Miltefosine may be administered via in-home caregiver Directly Observed Therapy (cDOT), while patients must travel to clinics to receive MA. We performed a cost-effectiveness analysis comparing miltefosine by cDOT versus MA for pediatric CL in southwest Colombia. METHODOLOGY/PRINCIPLE FINDINGS: We developed a Monte Carlo model comparing the cost-per-cure of miltefosine by cDOT compared to MA from patient, government payer, and societal perspectives (societal = sum of patient and government payer perspective costs). Drug effectiveness and adverse events were estimated from clinical trials. Healthcare utilization and costs of travel were obtained from surveys of providers and published sources. The primary outcome was cost-per-cure reported in 2015 USD. Treatment efficacy, costs, and adherence were varied in sensitivity analysis to assess robustness of results. Treatment with miltefosine resulted in substantially lower cost-per-cure from a societal and patient perspective, and slightly higher cost-per-cure from a government payer perspective compared to MA. Mean societal cost-per-cure were $531 (SD±$239) for MA and $188 (SD±$100) for miltefosine, a mean cost-per-cure difference of +$343. Mean cost-per-cure from a patient perspective were $442 (SD ±$233) for MA and $30 (SD±$16) for miltefosine, a mean difference of +$412. Mean cost-per-cure from a government perspective were $89 (SD±$55) for MA and $158 (SD±$98) for miltefosine, with a mean difference of -$69. Results were robust across a variety of assumptions in univariate and multi-way analysis. CONCLUSIONS/SIGNIFICANCE: Treatment of pediatric cutaneous leishmaniasis with miltefosine via cDOT is cost saving from patient and societal perspectives, and moderately more costly from the government payer perspective compared to treatment with MA. Results were robust over a range of sensitivity analyses. Lower drug price for miltefosine could result in cost saving from a government perspective.

Use of Optical Imaging Technology in the Validation of a New, Rapid, Cost-Effective Drug Screen as Part of a Tiered In Vivo Screening Paradigm for Development of Drugs To Treat Cutaneous Leishmaniasis.

In any drug discovery and development effort, a reduction in the time of the lead optimization cycle is critical to decrease the time to license and reduce costs. In addition, ethical guidelines call for the more ethical use of animals to minimize the number of animals used and decrease their suffering. Therefore, any effort to develop drugs to treat cutaneous leishmaniasis requires multiple tiers of in vivo testing that start with higher-throughput efficacy assessments and progress to lower-throughput models with the most clinical relevance. Here, we describe the validation of a high-throughput, first-tier, noninvasive model of lesion suppression that uses an in vivo optical imaging technology for the initial screening of compounds. A strong correlation between luciferase activity and the parasite load at up to 18 days postinfection was found. This correlation allows the direct assessment of the effects of drug treatment on parasite burden. We demonstrate that there is a strong correlation between drug efficacy measured on day 18 postinfection and the suppression of lesion size by day 60 postinfection, which allows us to reach an accurate conclusion on drug efficacy in only 18 days. Compounds demonstrating a significant reduction in the bioluminescence signal compared to that in control animals can be tested in lower-throughput, more definitive tests of lesion cure in BALB/c mice and Golden Syrian hamsters (GSH) using Old World and New World parasites.

Topical Treatment of Leishmania tropica Infection Using (-)-α-Bisabolol Ointment in a Hamster Model: Effectiveness and Safety Assessment.

There is currently no reliable treatment for the management of cutaneous leishmaniasis, and intralesional antimonial injections remain the main treatment. The present work aims at evaluating the antileishmanial effectiveness and safety of (-)-α-bisabolol (1) in a novel topical formulation on a cutaneous leishmaniasis model involving Leishmania tropica-infected Syrian hamsters. The topical treatment with 1 reduced lesion thickness to 56% at 2.5%, showing a higher efficacy than the reference control, meglumine antimoniate. Other regimens (ointment at 1% and 5% and oral treatment at 200 mg/kg) reduced the footpad thickness as well. The skin parasite load decreased after the experiment in all treatment groups, particularly in those animals treated with the 2.5% formulation (83.2%). Treatment with (-)-α-bisabolol at different concentrations or through an oral route did not lead to the appearance of toxicity or side effects in healthy hamsters or infected animals. Therefore, topical (-)-α-bisabolol was more effective than meglumine antimoniate in this cutaneous leishmaniasis model without showing toxicity effects on the hamsters. These results are of great interest and might be used for the development of alternatives for the treatment of cutaneous leishmaniasis, either in monotherapy or in combination with other drugs whose skin permeability could be enhanced by this sesquiterpene.

Cost of Pediatric Visceral Leishmaniasis Care in Morocco.

BACKGROUND: Visceral leishmaniasis (VL) is a neglected parasitic disease that is fatal if left untreated. VL is endemic in Morocco and other countries in North Africa were it mainly affects children from rural areas. In Morocco, the direct observation of Leishmania parasites in bone marrow aspirates and serological tests are used to diagnose VL. Glucantime is the first line of treatment. The objective of this study was to report the costs associated to standard clinical management of pediatric VL from the provider perspective in Morocco. As a secondary objective we described the current clinical practices and the epidemiological characteristics of pediatric VL patients. METHODS: From March to June 2014 we conducted a survey in eight hospitals treating pediatric VL patients in Morocco. A pro-forma was used to collect demographic, clinical and management data from medical records. We specifically collected data on VL diagnosis and treatment. We also estimated the days of hospitalization and the time to start VL treatment. Costs were estimated by multiplying the use of resources in terms of number of days in hospital, tests performed and drugs provided by the official prices. For patients receiving part of their treatment at Primary Health Centers (PHC) we estimated the cost of administering the Glucantime as outpatient. We calculated the median cost per VL patient. We also estimated the cost of managing a VL case when different treatment strategies were applied: inpatient and outpatient. RESULTS: We obtained data from 127 VL patients. The median total cost per pediatric VL case in Morocco is 520 US$. The cost in hospitals applying an outpatient strategy is significantly lower (307 US$) than hospitals keeping the patients for the whole treatment (636 US$). However the outpatient strategy is not yet recommended as VL treatment for children in the Moroccan guidelines. VL diagnosis and treatment regimens should be standardized following the current guidelines in Morocco.

Assessment of drug resistance related genes as candidate markers for treatment outcome prediction of cutaneous leishmaniasis in Brazil.

The great public health problem posed by leishmaniasis has substantially worsened in recent years by the emergence of clinical failure. In Brazil, the poor prognosis observed for patients infected by Leishmania braziliensis (Lb) or L. guyanensis (Lg) may be related to parasite drug resistance. In the present study, 19 Lb and 29 Lg isolates were obtained from infected patients with different treatment outcomes. Translated amino acid sequence polymorphisms from four described antimony resistance related genes (AQP1, hsp70, MRPA and TRYR) were tested as candidate markers for antimonial treatment failure prediction. Possibly due to the low intraspecific variability observed in Lg samples, none of the prediction models had good prognosis values. Most strikingly, one mutation (T579A) found in hsp70 of Lb samples could predict 75% of the antimonial treatment failure clinical cases. Moreover, a multiple logistic regression model showed that the change from adenine to guanine at position 1735 of the hsp70 gene, which is responsible for the T579A mutation, significantly increased the chance of Lb clinical isolates to be associated with treatment failure (OR=7.29; CI 95%=[1.17, 45.25]; p=0.0331). The use of molecular markers to predict treatment outcome presents practical and economic advantages as it allows the development of rapid assays to monitor the emergence of drug resistant parasites that can be clinically applied to aid the prognosis of cutaneous leishmaniasis in Brazil.

Novel approach to in vitro drug susceptibility assessment of clinical strains of Leishmania spp.

Resistance to antimonial drugs has been documented in Leishmania isolates transmitted in South America, Europe, and Asia. The frequency and distribution of resistance to these and other antileishmanial drugs are unknown. Technical constraints have limited the assessment of drug susceptibility of clinical strains of Leishmania. Susceptibility of experimentally selected lines and 130 clinical strains of Leishmania panamensis, L. braziliensis, and L. guyanensis to meglumine antimoniate and miltefosine was determined on the basis of parasite burden and percentage of infected U-937 human macrophages. Reductions of infection at single predefined concentrations of meglumine antimoniate and miltefosine and 50% effective doses (ED(50)s) were measured and correlated. The effects of 34°C and 37°C incubation temperatures and different parasite-to-host cell ratios on drug susceptibility were evaluated at 5, 10, and 20 parasites/cell. Reduction of the intracellular burden of Leishmania amastigotes in U-937 cells exposed to the predefined concentrations of meglumine antimoniate or miltefosine discriminated sensitive and experimentally derived resistant Leishmania populations and was significantly correlated with ED(50) values of clinical strains (for meglumine antimoniate, ρ = -0.926 and P < 0.001; for miltefosine, ρ = -0.906 and P < 0.001). Incubation at 37°C significantly inhibited parasite growth compared to that at 34°C in the absence of antileishmanial drugs and resulted in a significantly lower ED(50) in the presence of drugs. Susceptibility assessment was not altered by the parasite-to-cell ratio over the range evaluated. In conclusion, measurement of the reduction of parasite burden at a single predetermined drug concentration under standardized conditions provides an efficient and reliable strategy for susceptibility evaluation and monitoring of clinical strains of Leishmania.

Combination therapy for visceral leishmaniasis.

Combination therapy for the treatment of visceral leishmaniasis has increasingly been advocated as a way to increase treatment efficacy and tolerance, reduce treatment duration and cost, and limit the emergence of drug resistance. We reviewed the evidence and potential for combination therapy, and the criteria for the choice of drugs in such regimens. The first phase 2 results of combination regimens are promising, and have identified effective and safe regimens as short as 8 days. Several phase 3 trials are underway or planned in the Indian subcontinent and east Africa. The limited data available suggest that combination therapy is more cost-effective and reduces indirect costs for patients. Additional advantages are reduced treatment duration (8-17 days), with potentially better patient compliance and lesser burden on the health system. Only limited data are available on how best to prevent acquired resistance. Patients who are coinfected with visceral leishmaniasis and HIV could be a reservoir for development and spread of drug-resistant strains, calling for special precautions. The identification of a short, cheap, well-tolerated combination regimen that can be given in ambulatory care and needs minimal clinical monitoring will most likely have important public health implications. Effective monitoring systems and close regulations and policy will be needed to ensure effective implementation. Whether combination therapy could indeed help delay resistance, and how this is best achieved, will only be known in the long term.

The efficacy of thermotherapy to treat cutaneous leishmaniasis in Colombia: a comparative observational study in an operational setting.

An open label, comparative study to compare the efficacy of thermotherapy to meglumine antimoniate in treating cutaneous leishmaniasis patients in an operational context was carried out in Chaparral, Colombia. After enrollment patients were followed-up for up to 100 days. Per protocol and intention-to-treat cure rates for 47 patients treated using thermotherapy (one-time 50 degrees C applications for 30s) were 100 and 19%, respectively. Per protocol and intention-to-treat cure rates for meglumine antimoniate (20 mg/kg body weight administered intramuscularly for 21 d) were 78 and 23%, respectively.

Short communication: The cost-effectiveness of cutaneous leishmaniasis patient management during an epidemic in Chaparral, Colombia in 2004.

We calculated ranges for the cost per disability adjusted life year (DALY) averted for cutaneous leishmaniasis (CL) treatment during an ongoing epidemic of CL in Chaparral, Colombia. Using operational clinical and cost data, we calculated that the cost of treating leishmaniasis patients with standard pentavalent antimony was US$345 (95% CI 277-488) per patient treated and cured. The cost per DALY averted per patient cured with antimony was estimated to be approximately US$15 000 (95% CI 12 226-21 532).