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Showing papers on "Visceral leishmaniasis published in 2015"


Journal ArticleDOI
TL;DR: There is an urgent need to implement a single-dose L-AmB or combination therapy in the Indian subcontinent for the treatment of post – kala-azar dermal leishmaniasis.
Abstract: Introduction: Leishmaniasis broadly manifests as visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis. The treatment of leishmaniasis is challenging and the armamentarium of drugs is small, duration of treatment is long, and most drugs are toxic.Areas covered: A literature search on treatment of leishmaniasis was done on PubMed. Single dose of liposomal amphotericin B (L-AmB) and multidrug therapy (L-AmB + miltefosine, L-AmB + paromomycin (PM), or miltefosine + PM) are the treatment of choice for VL in the Indian subcontinent. A 17-day combination therapy of pentavalent antimonials (Sbv) and PM remains the treatment of choice for East African VL. L-AmB at a total dose of 18 – 21 mg/kg is the recommended regimen for VL in the Mediterranean region and South America. Treatment of CL should be decided by the severity of clinical lesions, etiological species and its potential to develop into mucosal leishmaniasis.Expert opinion: There is an urgent need to implement a single...

227 citations


Journal ArticleDOI
TL;DR: The diagnostic, chemotherapeutic, and immunizing strategies to control leishmaniasis are highlighted, though no human vaccine is commercially available currently owing to the complexity of the cellular immune response to this parasite.
Abstract: Leishmaniasis is a neglected vector-borne tropical infection considered to be a disease of the poor. Concentrated in poverty-stricken countries within Southeast Asia, East Africa, and Latin America, it is also endemic in several Mediterranean countries. The management of the heterogeneous syndromes determined by parasites belonging to the genus Leishmania is particularly difficult in developed, non-endemic countries owing to the unfamiliarity of physicians with clinical symptoms, diagnostic possibilities, and available treatment options. Therefore, travelers and other people who may be exposed to sand flies in endemic areas should receive counseling regarding leishmaniasis and appropriate protective measures. Serological diagnosis is rarely used for cutaneous and mucocutaneous diseases, but it is the most commonly used technique for visceral leishmaniasis. The drugs used to treat this last disease are expensive and sometimes have toxic side effects. This review highlights the diagnostic, chemotherapeutic, and immunizing strategies to control leishmaniasis, though no human vaccine is commercially available currently owing to the complexity of the cellular immune response to this parasite.

141 citations


Reference EntryDOI
TL;DR: This unit focuses on the murine model of cutaneous leish maniasis and models of visceral leishmaniasis in mice and hamsters, and describes the methods used to inoculate parasites and to evaluate infections with regard to lesion progression and visceralization, and quantification of parasite load.
Abstract: This unit focuses on the murine model of cutaneous leishmaniasis and models of visceral leishmaniasis in mice and hamsters. Each basic protocol describes the methods used to inoculate parasites and to evaluate infections with regard to lesion progression and visceralization, and quantification of parasite load.

130 citations


Journal ArticleDOI
TL;DR: Visceral leishmaniasis is one of the most severely neglected tropical diseases recognized by the World Health Organization and few vaccines including Leishmune®, Leishtec, and CaniLeish® have been licensed for canine visceral leish maniasis.

129 citations


Journal ArticleDOI
TL;DR: The vaccine candidate was shown to be safe and induced a strong antigen‐specific immune response, as evidenced by cytokine and immunoglobulin subclass data, which provide a strong rationale for additional trials in Leishmania‐endemic countries in populations vulnerable to VL.
Abstract: Key antigens of Leishmania species identified in the context of host responses in Leishmania-exposed individuals from disease-endemic areas were prioritized for the development of a subunit vaccine against visceral leishmaniasis (VL), the most deadly form of leishmaniasis. Two Leishmania proteins—nucleoside hydrolase and a sterol 24-c-methyltransferase, each of which are protective in animal models of VL when properly adjuvanted— were produced as a single recombinant fusion protein NS (LEISH-F3) for ease of antigen production and broad coverage of a heterogeneous major histocompatibility complex population. When formulated with glucopyranosyl lipid A-stable oil-in-water nanoemulsion (GLA-SE), a Toll-like receptor 4 TH1 (T helper 1) promoting nanoemulsion adjuvant, the LEISH-F3 polyprotein induced potent protection against both L. donovani and L. infantum in mice, measured as significant reductions in liver parasite burdens. A robust immune response to each component of the vaccine with polyfunctional CD4 TH1 cell responses characterized by production of antigen-specific interferon-γ, tumor necrosis factor and interleukin-2 (IL-2), and low levels of IL-5 and IL-10 was induced in immunized mice. We also demonstrate that CD4 T cells, but not CD8 T cells, are sufficient for protection against L. donovani infection in immunized mice. Based on the sum of preclinical data, we prepared GMP materials and performed a phase 1 clinical study with LEISH-F3+GLA-SE in healthy, uninfected adults in the United States. The vaccine candidate was shown to be safe and induced a strong antigen-specific immune response, as evidenced by cytokine and immunoglobulin subclass data. These data provide a strong rationale for additional trials in Leishmania-endemic countries in populations vulnerable to VL.

117 citations


Journal ArticleDOI
TL;DR: The developments of the last decade are reviewed, covering all aspects of leishmaniasis including clinically used drugs, various new classes of antileishmanial agents (synthetic as well as natural), patented antileISHmanialagents, and possible drug targets.
Abstract: Leishmaniasis, a group of diseases caused by hemoflagellate obligate intracellular protozoa (trypanosomatids) from the genus Leishmania, has not received the attention it deserves and has developed into a major health problem in developing countries. No effective vaccine is available against leishmaniasis, so chemotherapy is the only effective way to treat all forms of the disease. However, the drugs currently used for treatment of human cutaneous and visceral leishmaniasis are toxic, having severe adverse reactions which limit their use. Therefore, development of novel, effective, and safe antileishmanial agents, with reduced side effects, is a major priority for health researchers, and large numbers of research reports have been published on antileishmanial agents in the last 10 years. Herein, we comprehensively review the developments of the last decade, covering all aspects of leishmaniasis including clinically used drugs, various new classes of antileishmanial agents (synthetic as well as natural), patented antileishmanial agents, and possible drug targets.

114 citations


Journal ArticleDOI
TL;DR: The incidences of cutaneous and zoonotic visceral leish maniasis have decreased in recent years, which coincides with national leishmaniasis control efforts.
Abstract: Leishmaniasis has a long history in the Islamic Republic of Iran. This study aimed to show the trend in leishmaniasis incidence from 1983 to 2012 and to describe the epidemiological characteristics in 2012. In a retrospective cross-sectional study, data were extracted from th%e national leishmaniasis surveillance system for the 3 clinical types-cutaneous (zoonotic and anthroponotic) and visceral (zoonotic). The average annual number of cutaneous leishmaniasis cases was 18 884 (average annual incidence 32 cases per 100 000 inhabitants). In 2012 the highest incidences were in age groups 1-4 and 5-9-years (43 and 40 per 100 000), and more males (57%) than females (43%) were infected. The annual average number of zoonotic visceral leishmaniasis cases was 175 (average annual incidence 0.18 per 100 000). The incidences of cutaneous and zoonotic visceral leishmaniasis have decreased in recent years, which coincides with national leishmaniasis control efforts.

96 citations


Journal ArticleDOI
TL;DR: A retrospective study of visceral leishmaniasis in organ transplant patients suggests that there may be a role for secondary prophylaxis after treatment akin to HIV coinfection recommendations, and the pros and cons of oral therapy with miltefosine are discussed.
Abstract: Purpose of reviewThis review summarizes recent important and interesting articles investigating the challenging treatment of the parasitic infection, leishmaniasis. In addition, it compares and contrasts leishmaniasis clinical practice treatment guidelines.Recent findingsStudies show that, in contra

95 citations


Journal ArticleDOI
TL;DR: Only two vaccines showed to confer significant protection against disease and death under natural conditions, and have been registered as canine vaccines: FML-QuilA (Leishmune(®) in Brazil, and LiESP/QA-21 (CaniLeish(®)) in Europe.

91 citations


Journal ArticleDOI
TL;DR: It is shown via a facilitated knockout approach that chromosomal CYP51 genes can only be knocked out in the presence of episomal complementation and that this episome cannot be lost from the parasite even under negative selection, and support for further development of CYP 51 inhibitors for the treatment of visceral leishmaniasis is provided.
Abstract: Leishmania protozoan parasites (Trypanosomatidae family) are the causative agents of cutaneous, mucocutaneous and visceral leishmaniasis worldwide. While these diseases are associated with significant morbidity and mortality, there are few adequate treatments available. Sterol 14alpha-demethylase (CYP51) in the parasite sterol biosynthesis pathway has been the focus of considerable interest as a novel drug target in Leishmania. However, its essentiality in Leishmania donovani has yet to be determined. Here, we use a dual biological and pharmacological approach to demonstrate that CYP51 is indispensable in L. donovani. We show via a facilitated knockout approach that chromosomal CYP51 genes can only be knocked out in the presence of episomal complementation and that this episome cannot be lost from the parasite even under negative selection. In addition, we treated wild-type L. donovani and CYP51-deficient strains with 4-aminopyridyl-based inhibitors designed specifically for Trypanosoma cruzi CYP51. While potency was lower than in T. cruzi, these inhibitors had increased efficacy in parasites lacking a CYP51 allele compared to complemented parasites, indicating inhibition of parasite growth via a CYP51-specific mechanism and confirming essentiality of CYP51 in L. donovani. Overall, these results provide support for further development of CYP51 inhibitors for the treatment of visceral leishmaniasis.

83 citations


Journal ArticleDOI
TL;DR: Strategies to prevent the development and spread of miltefosine resistance are urgently needed and Appropriate regimens for New World mucocutaneous leishmaniasis need to be established, although longer treatment duration seems to confer better results.
Abstract: Miltefosine is the only recognized oral agent with potential to treat leishmaniasis. Miltefosine had demonstrated very good cure rates for visceral leishmaniasis (VL) in India, Nepal, and Bangladesh, but high rates of clinical failures have been recently reported. Moderate efficacy has been observed for VL in East Africa, whereas data from Mediterranean countries and Latin America are scarce. Results have not been very promising for patients coinfected with VL and human immunodeficiency virus. However, miltefosine's long half-life and its oral administration could make it a good option for maintenance prophylaxis. Good evidence of efficacy has been documented in Old World cutaneous leishmaniasis (CL), and different cure rates among New World CL have been obtained depending on the geographical areas and species involved. Appropriate regimens for New World mucocutaneous leishmaniasis need to be established, although longer treatment duration seems to confer better results. Strategies to prevent the development and spread of miltefosine resistance are urgently needed.

Journal ArticleDOI
TL;DR: The current status of epidemiology, diagnosis, treatment, and prevention of the disease, with particular reference to the control programs, is described in some depth and breadth.
Abstract: Visceral leishmaniasis (VL) caused by Leishmania spp. is an important vector-borne and largely zoonotic disease. In China, three epidemiological types of VL have been described: anthroponotic VL (AVL), mountain-type zoonotic VL (MT-ZVL), and desert-type ZVL (DT-ZVL). These are transmitted by four different sand fly species: Phlebotomus chinensis, P. longiductus, P. wui, and P. alexandri. In 1951, a detailed survey of VL showed that it was rampant in the vast rural areas west, northwest, and north of the Yangtze River. Control programs were designed and implemented stringently by the government at all administrative levels, resulting in elimination of the disease from most areas of endemicity, except the western and northwestern regions. The control programs consisted of (i) diagnosis and chemotherapy of patients, (ii) identification, isolation, and disposal of infected dogs, and (iii) residual insecticide indoor spraying for vector control. The success of the control programs is attributable to massive and effective mobilization of the general public and health workers to the cause. Nationally, the annual incidence is now very low, i.e., only 0.03/100,000 according to the available 2011 official record. The overwhelming majority of cases are reported from sites of endemicity in the western and northwestern regions. Here, we describe in some depth and breadth the current status of epidemiology, diagnosis, treatment, and prevention of the disease, with particular reference to the control programs. Pertinent information has been assembled from scattered literature of the past decades in different languages that are not readily accessible to the scientific community. The information provided constitutes an integral part of our knowledge on leishmaniasis in the global context and will be of special value to those interested in control programs.

Journal ArticleDOI
TL;DR: These new formulations, when adjusted with regard to their production costs, may be considered new drug delivery systems that promise to improve the treatment of leishmaniasis, by reducing the side effects and the number of doses while permitting a satisfactory cost-benefit ratio.
Abstract: Leishmaniasis is one of the six major tropical diseases targeted by the World Health Organization. It is a life-threatening disease of medical, social and economic importance in endemic areas. No vaccine is yet available for human use, and chemotherapy presents several problems. Pentavalent antimonials have been the drugs of choice to treat the disease for more than six decades; however, they exhibit high toxicity and are not indicated for children, for pregnant or breastfeeding women or for chronically ill patients. Amphotericin B (AmpB) is a second-line drug, and although it has been increasingly used to treat visceral leishmaniasis (VL), its clinical use has been hampered due to its high toxicity. This review focuses on the development and in vivo usage of new delivery systems for AmpB that aim to decrease its toxicity without altering its therapeutic efficacy. These new formulations, when adjusted with regard to their production costs, may be considered new drug delivery systems that promise to improve the treatment of leishmaniasis, by reducing the side effects and the number of doses while permitting a satisfactory cost-benefit ratio.

Journal ArticleDOI
TL;DR: The results advocate superior efficacy of ALPLGA nanoparticles over free artemisinin, which was coupled with restoration of suppressed cell-mediated immunity in animal models of VL.

Journal ArticleDOI
TL;DR: A significant increase of hospitalization in the absence of HIV co-infection is suggested, with a predomination of VL, and clinicians in Spain should be aware of leishmaniasis not only in the HIV population but also in non HIV patients, especially for those having immunosuppression as an associate condition.
Abstract: In Spain, Leishmania infantum is endemic, human visceral and cutaneous leishmaniasis cases occurring both in the Peninsula, as well as in the Balearic Islands. We aimed to describe the clinical characteristics of leishmaniasis patients and the changes in the disease evolution after the introduction of antiretroviral therapy in 1997. In this descriptive study, we used Spanish Centralized Hospital Discharge Database for the hospitalized leishmaniasis cases between 1997 and 2011. We included in the analysis only the records having leishmaniasis as the first registered diagnosis and calculated the hospitalization rates. Disease trend was described taking into account the HIV status. Adjusted odds-ratio was used to estimate the association between clinical and socio-demographic factors and HIV co-infection. Of the total 8010 Leishmaniasis hospitalizations records, 3442 had leishmaniasis as first diagnosis; 2545/3442 (75.6%) were males and 2240/3442 (65.1%) aged between 14-65 years. Regarding disease forms, 2844/3442 (82.6%) of hospitalizations were due to visceral leishmaniasis (VL), while 118/3442 (3.4%) hospitalizations were cutaneous leishmaniasis (CL). Overall, 1737/2844 of VL (61.1%) were HIV negatives. An overall increasing trend was observed for the records with leishmaniasis as first diagnosis (p=0.113). Non-HIV leishmaniasis increased during this time period (p=0.021) while leishmaniasis-HIV co-infection hospitalization revealed a slight descending trend (p=0.717). Leishmaniasis-HIV co-infection was significantly associated with male sex (aOR=1.6; 95% CI: 1.25-2.04), 16-64 years age group (aOR=17.4; 95%CI: 2.1-143.3), visceral leishmaniasis aOR=6.1 (95%CI: 3.27-11.28) and solid neoplasms 4.5 (95% CI: 1.65-12.04). The absence of HIV co-infection was associated with lymph/hematopoietic neoplasms (aOR=0.3; 95%CI:0.14-0.57), other immunodeficiency (aOR=0.04; 95% CI:0.01-0.32) and transplant (aOR=0.01; 95%CI:0.00-0.07). Our findings suggest a significant increase of hospitalization in the absence of HIV co-infection, with a predomination of VL. We consider that clinicians in Spain should be aware of leishmaniasis not only in the HIV population but also in non HIV patients, especially for those having immunosuppression as an associate condition.

Journal ArticleDOI
TL;DR: The ways in which neutrophils have been observed to prevent and promote the establishment of infection are discussed, the role of anti‐neutrophil antibodies in mouse models of leishmaniasis is examined and recent findings that neutrophil may play a previously unrecognized role in influencing chronic parasite persistence are considered.
Abstract: Leishmania parasites are the causative agents of leishmaniasis, a neglected tropical disease that causes substantial morbidity and considerable mortality in many developing areas of the world. Recent estimates suggest that roughly 10 million people suffer from cutaneous leishmaniasis (CL), and approximately 76,000 are afflicted with visceral leishmaniasis (VL), which is universally fatal without treatment. Efforts to develop therapeutics and vaccines have been greatly hampered by an incomplete understanding of the parasite's biology and a lack of clear protective correlates that must be met in order to achieve immunity. Although parasites grow and divide preferentially in macrophages, a number of other cell types interact with and internalize Leishmania parasites, including monocytes, dendritic cells and neutrophils. Neutrophils appear to be especially important shortly after parasites are introduced into the skin, and may serve a dual protective and permissive role during the establishment of infection. Curiously, neutrophil recruitment to the site of infection appears to continue into the chronic phase of disease, which may persist for many years. The immunological impact of these cells during chronic leishmaniasis is unclear at this time. In this review we discuss the ways in which neutrophils have been observed to prevent and promote the establishment of infection, examine the role of anti-neutrophil antibodies in mouse models of leishmaniasis and consider recent findings that neutrophils may play a previously unrecognized role in influencing chronic parasite persistence.

Journal ArticleDOI
TL;DR: A simple colorimetric loop-mediated isothermal amplification (LAMP) technique for the direct detection of Leishmania DNA could enable the rapid diagnosis of leishmaniasis, thereby facilitating the survey and control of leishingmaniasis in Thailand.
Abstract: Leishmaniasis is a neglected tropical disease that is caused by an obligate intracellular protozoan of the genus Leishmania. Recently, an increasing number of autochthonous leishmaniasis cases caused by L. martiniquensis and the novel species L. siamensis have been described in Thailand, rendering an accurate diagnosis of this disease critical. However, only a few laboratories are capable of diagnosing leishmaniasis in Thailand. To expand leishmaniasis diagnostic capabilities, we developed a simple colorimetric loop-mediated isothermal amplification (LAMP) technique for the direct detection of Leishmania DNA. LAMP was performed for 75 min using four primers targeting the conserved region of the18S ribosomal RNA gene, and the DNA indicator used was malachite green (MG). To simulate crude samples, cultured promastigotes of L. siamensis were mixed with blood or saliva. Also, clinical samples (blood, saliva, and tissue biopsies) were obtained from patients with cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). All samples were boiled for 10 min and introduced directly into the LAMP reaction mixture without DNA purification. The use of MG resulted in an unambiguous differentiation of positive and negative controls. For L. siamensis, the detection limit was 103 parasites/mL or 2.5 parasites/tube. Saliva, tissue biopsies, and whole blood were indicative of active Leishmania infection, and their direct usages did not adversely affect the detection limit. In addition, this LAMP assay could detect DNA from multiple Leishmania species other than L. siamensis and L. martiniquensis, including L. aethiopica, L. braziliensis, L. donovani and L. tropica. The simplicity and sensitivity of LAMP in detecting active Leishmania infection could enable the rapid diagnosis of leishmaniasis, thereby facilitating the survey and control of leishmaniasis in Thailand. However, our limited number of samples warranted a further validation with a larger cohort of patients before this assay could be deployed.

Journal ArticleDOI
TL;DR: Pentamidine secondary prophylaxis led to a 29% failure rate within one year, much lower than reported in historical controls (50%-100%).
Abstract: Background Visceral leishmaniasis (VL) has become an important opportunistic infection in persons with HIV-infection in VL-endemic areas. The co-infection leads to profound immunosuppression and high rate of annual VL recurrence. This study assessed the effectiveness, safety and feasibility of monthly pentamidine infusions to prevent recurrence of VL in HIV co-infected patients.

Journal ArticleDOI
03 Mar 2015-PLOS ONE
TL;DR: Overall, rKLO8- and rK39 ELISA were most sensitive in immunocompetent patients from all endemic regions (96–100%) and the sensitivity was reduced to 81.8% in HIV co-infected patients from France.
Abstract: Diagnostic tests for visceral leishmaniasis that are based on antigens of a single Leishmania strain can have low diagnostic performance in regions where heterologous parasites predominate. The aim of this study was to investigate and compare the performance of five serological tests, based on different Leishmania antigens, in three endemic countries for visceral leishmaniasis. A total number of 231 sera of symptomatic and asymptomatic cases and controls from three endemic regions of visceral leishmaniasis in East Sudan, North India and South France were evaluated by following serological tests: rKLO8- and rK39 ELISA, DAT (ITMA-DAT) and two rapid tests of rK39 (IT LEISH) and rKE16 (Signal-KA). Overall, rKLO8- and rK39 ELISA were most sensitive in immunocompetent patients from all endemic regions (96–100%) and the sensitivity was reduced to 81.8% in HIV co-infected patients from France. Sera of patients from India demonstrated significantly higher antibody responses to rKLO8 and rK39 compared with sera from Sudan (p<0.0001) and France (p<0.0037). Further, some Indian and Sudanese patients reacted better with rKLO8 than rK39. Sensitivity of DAT (ITMA-DAT) was high in Sudan (94%) and India (92.3%) but low in France being 88.5% and 54.5% for VL and VL/HIV patients, respectively. In contrast, rapid tests displayed high sensitivity only in patients from India (96.2%) but not Sudan (64–88%) and France (73.1–88.5% and 63.6–81.8% in VL and VL/HIV patients, respectively). While the sensitivity varied, all tests showed high specificity in Sudan (96.7–100%) and India (96.6%).Heterogeneity of Leishmania parasites which is common in many endemic regions complicates the diagnosis of visceral leishmaniasis. Therefore, tests based on homologous Leishmania antigens are required for particular endemic regions to detect cases which are difficult to be diagnosed with currently available tests.

Journal ArticleDOI
TL;DR: It is revealed that, along with leishmanicidal activity, DNDI-VL-2098 was also capable of inducing host-protective immune cells to suppress Leishmania parasites in hamsters.
Abstract: OBJECTIVES: The objective of this study was to identify a nitroimidazo-oxazole lead molecule for the treatment of visceral leishmaniasis (VL). METHODS: A library of 72 nitroimidazo-oxazoles was evaluated in vitro for their antileishmanial activity against luciferase-transfected DD8 amastigotes of Leishmania donovani. On the basis of their in vitro potency and pharmacokinetic properties, the promising compounds were tested in acute BALB/c mouse and chronic hamster models of VL via oral administration and efficacy was evaluated by microscopic counting of amastigotes after Giemsa staining. The best antileishmanial candidates (racemate DNDI-VL-2001) and its R enantiomer (DNDI-VL-2098) were evaluated in vitro against a range of Leishmania strains. These candidates were further studied in a hamster model using various dose regimens. Cytokine and inducible nitric oxide synthase estimations by real-time PCR and nitric oxide generation by Griess assay were also carried out for DNDI-VL-2098. RESULTS: In vitro screening of nitroimidazo-oxazole compounds identified the racemate DNDI-VL-2001 (6-nitroimidazo-oxazole derivative) and its enantiomers as candidates for further evaluation in in vivo models of VL. DNDI-VL-2098 (IC50 of 0.03 μM for the DD8 strain) showed excellent in vivo activity in both mouse and hamster models, with an ED90 value of 3.7 and <25 mg/kg, respectively, and was also found to be very effective against high-grade infection in the hamster model. Our studies revealed that, along with leishmanicidal activity, DNDI-VL-2098 was also capable of inducing host-protective immune cells to suppress Leishmania parasites in hamsters. CONCLUSIONS: These studies led to the identification of compound DNDI-VL-2098 as a preclinical candidate for further drug development as an oral treatment for VL.

Journal ArticleDOI
TL;DR: This study shows that ELISA using the multiepitope proteins PQ10 and PQ20 has great potential in early CVL diagnosis and the use of these proteins in other methodologies, such as immunochromatographic tests, could be beneficial mainly for the detection of asymptomatic dogs.
Abstract: BACKGROUND: Visceral leishmaniasis is the most severe form of leishmaniasis. Worldwide, approximately 20% of zoonotic human visceral leishmaniasis is caused by Leishmania infantum, also known as Leishmania chagasi in Latin America. Current diagnostic methods are not accurate enough to identify Leishmania-infected animals and may compromise the effectiveness of disease control. Therefore, we aimed to produce and test two recombinant multiepitope proteins as a means to improve and increase accuracy in the diagnosis of canine visceral leishmaniasis (CVL). METHODOLOGY/PRINCIPAL FINDINGS: Ten antigenic peptides were identified by CVL ELISA in previous work. In the current proposal, the coding sequences of these ten peptides were assembled into a synthetic gene. Furthermore, other twenty peptides were selected from work by our group where good B and T cell epitopes were mapped. The coding sequences of these peptides were also assembled into a synthetic gene. Both genes have been cloned and expressed in Escherichia coli, producing two multiepitope recombinant proteins, PQ10 and PQ20. These antigens have been used in CVL ELISA and were able to identify asymptomatic dogs (80%) more effectively than EIE-LVC kit, produced by Bio-Manguinhos (0%) and DPP kit (10%). Moreover, our recombinant proteins presented an early detection (before PCR) of infected dogs, with positivities ranging from 23% to 65%, depending on the phase of infection in which sera were acquired. CONCLUSIONS/SIGNIFICANCE: Our study shows that ELISA using the multiepitope proteins PQ10 and PQ20 has great potential in early CVL diagnosis. The use of these proteins in other methodologies, such as immunochromatographic tests, could be beneficial mainly for the detection of asymptomatic dogs.

Journal ArticleDOI
TL;DR: The safety and efficacy of treating visceral leishmaniasis in patients with human immunodeficiency virus-VL coinfection with concurrent intravenous liposomal amphotericin B (AmBisome) and oral miltefosine (Impavido) in India was described.
Abstract: Visceral leishmaniasis (VL; Kala-azar) is a vector-borne disease caused by Leishmania donovani parasites. VL is endemic in the Indian state of Bihar, which accounts for 40% of the worldwide burden of VL [1]. Although the prevalence of human immunodeficiency virus (HIV) in Bihar is considered low (0.2%–0.3%), it is one of the few states where prevalence is increasing [2]. A recent study from India has suggested that 2.4% of all patients ≥14 years of age presenting with VL were unknowingly coinfected with HIV [3]. HIV-infected patients are more likely to develop symptomatic VL due to reactivation of dormant Leishmania infection acquired prior to being infected with HIV or due to a much higher rate of clinical manifestation following primary Leishmania infection after acquiring HIV. Therefore, VL is generally considered an opportunistic infection in patients with HIV and often presents with atypical clinical features [4]. Coinfected patients are at higher risk of relapse and death, and this risk appears inversely correlated with CD4 counts. Furthermore, VL adversely affects the response to antiretroviral treatment [4, 5]. Worse outcomes and the treatment challenges faced by coinfected patients as compared to immunocompetent patients are well documented in the literature [6]. There are currently no evidence-based treatment recommendations for coinfected patients in Asia. Moreover, observational studies by Medecins Sans Frontieres (MSF) in India have shown that outcomes for HIV coinfected patients receiving 20 mg/kg AmBisome (Gilead Pharmaceuticals, Foster City, California) were substantially worse than in VL patients not known to be HIV coinfected [7–9], whereas a recent study in Ethiopia showed that 32% of coinfected patients demonstrated parasitological failure following treatment with 30 mg/kg AmBisome despite clinical improvement [10]. Therefore, the MSF VL treatment program in Bihar, in collaboration with the Rajendra Memorial Research Institute (RMRI), chose to treat HIV-VL coinfected patients on a compassionate basis using a combination of 30 mg/kg AmBisome and 14 days of miltefosine (Impavido, Paladin, Canada). This combination was adopted after consultation of experts, taking into account the synergistic properties of AmBisome and miltefosine [6, 11] and has been used in another center with promising results [12]. Additionally, the compassionate use of miltefosine in combination with liposomal amphotericin B (at 30 mg/kg total dose) in 111 HIV coinfected VL patients in east Africa seems to suggest substantially higher cure rates and lower failure rates both in primary VL and VL relapse than high-dose AmBisome monotherapy[12]. In this report, we describe the outcomes up to 18 months following treatment with this combination therapy under routine program conditions in Bihar, India.

Journal ArticleDOI
TL;DR: The findings suggest the eco-epidemiological importance of rodents in these foci of leishmaniasis and indicate that rodents are likely to play a role in the transmission of leishingmaniasis in Ethiopia, possibly as reservoir hosts.

Journal ArticleDOI
13 Apr 2015-PLOS ONE
TL;DR: In this article, the authors describe impairment on mRNA cytokine expression in leishmania infected dogs with high parasite load associated with a structural modification in the splenic lymphoid micro-architecture.
Abstract: Canine Visceral Leishmaniasis (CVL) shares many aspects with the human disease and dogs are considered the main urban reservoir of L infantum in zoonotic VL Infected dogs develop progressive disease with a large clinical spectrum A complex balance between the parasite and the genetic/immunological background of the host are decisive for infection evolution and clinical outcome This study comprised 92 Leishmania infected mongrel dogs of various ages from Mato Grosso, Brazil Spleen samples were collected for determining parasite load, humoral response, cytokine mRNA expression and histopathology alterations By real-time PCR for the ssrRNA Leishmania gene, two groups were defined; a low (lowP, n = 46) and a high parasite load groups (highP, n = 42) When comparing these groups, results show variable individual humoral immune response with higher specific IgG production in infected animals but with a notable difference in CVL rapid test optical densities (DPP) between highP and lowP groups Splenic architecture disruption was characterized by disorganization of white pulp, more evident in animals with high parasitism All cytokine transcripts in spleen were less expressed in highP than lowP groups with a large heterogeneous variation in response Individual correlation analysis between cytokine expression and parasite load revealed a negative correlation for both pro-inflammatory cytokines: IFNγ, IL-12, IL-6; and anti-inflammatory cytokines: IL-10 and TGFβ TNF showed the best negative correlation (r2 = 0231; p<0001) Herein we describe impairment on mRNA cytokine expression in leishmania infected dogs with high parasite load associated with a structural modification in the splenic lymphoid micro-architecture We also discuss the possible mechanism responsible for the uncontrolled parasite growth and clinical outcome

Journal ArticleDOI
TL;DR: There was a paradigm shift in compliance with miltefosine; however, increasing relapse rate indicated the need for newer therapies with oral formulations, and confirmatory diagnosis using minimally invasive skin slit aspirate samples would help overcome such issues.
Abstract: Background: Patients with Post kala-azar dermal leishmaniasis (PKDL) are considered a reservoir of Leishmania donovani. It is imperative to identify and treat them early for control of visceral leishmaniasis (VL), a current priority in the Indian subcontinent. We explored trends in clinico-epidemiological features of PKDL cases over last two decades, for improving management of the disease. Methods: Clinically suspected cases were diagnosed with rK39 strip test followed by parasitological confirmation by microscopy and/or PCR/qPCR in skin tissue/slit aspirates. Patients were treated with antimonials till 2008 and subsequently with miltefosine. Results: The study indicated higher incidence of PKDL cases in areas of high endemicity for VL, with 20 % cases reporting no history of VL. Approximately 26 % cases of PKDL were initially misdiagnosed at primary health centers. Duration between onset of PKDL and diagnosis was above 12 months in 80 % cases. Diagnostic sensitivity was 32-36 % with microscopy and 96–100 % with PCR/qPCR. Compliance to treatment was over 85 % with miltefosine while 15 % with antimonials. Relapse rate with miltefosine was up to 13.2 %.

Journal ArticleDOI
TL;DR: This is epidemiological and entomological evidence for ongoing local transmission of L. donovani in villages at an altitude above 600 meters in Nepal, in districts considered hitherto non-endemic for VL.
Abstract: Background In the Indian subcontinent, Visceral leishmaniasis is endemic in a geographical area coinciding with the Lower Gangetic Plain, at low altitude. VL occurring in residents of hill districts is therefore often considered the result of Leishmania donovani infection during travel. Early 2014 we conducted an outbreak investigation in Okhaldhunga and Bhojpur districts in the Nepal hills where increasing number of VL cases have been reported. Methodology/Principal Findings A house-to-house survey in six villages documented retrospectively 35 cases of Visceral Leishmaniasis (VL). Anti-Leishmania antibodies were found in 22/23 past-VL cases, in 40/416 (9.6%) persons without VL and in 12/155 (7.7%) domestic animals. An age- and sex- matched case-control study showed that exposure to known VL-endemic regions was no risk factor for VL, but having a VL case in the neighbourhood was. SSU-rDNA PCR for Leishmania sp. was positive in 24 (5%) of the human, in 18 (12%) of the animal samples and in 16 (14%) bloodfed female Phlebotomus argentipes sand flies. L. donovani was confirmed in two asymptomatic individuals and in one sand fly through hsp70-based sequencing. Conclusions/Significance This is epidemiological and entomological evidence for ongoing local transmission of L. donovani in villages at an altitude above 600 meters in Nepal, in districts considered hitherto non-endemic for VL. The VL Elimination Initiative in Nepal should therefore consider extending its surveillance and control activities in order to assure VL elimination, and the risk map for VL should be redesigned.

Journal ArticleDOI
TL;DR: It is confirmed that ethyl 2-acetyl-5-[4-butyl-2-(3-hydroxypentyl)-5-nitro-1H-imidazol-1-yl]pent-2-enoate can be a drug candidate against L. donovani for the treatment of VL in the Indian subcontinent.
Abstract: Visceral leishmaniasis (VL) affects Indian subcontinent, African and South American continent, and it covers 70 countries worldwide. Visceral form of leishmaniasis is caused by Leishmania donovani ...

Journal ArticleDOI
TL;DR: In this article, the in vitro and in vivo activity of (−)-α-bisabolol (1) against the etiological agents of visceral leishmaniasis was evaluated.
Abstract: The aim of the present study was to assess the in vitro and in vivo activity of (−)-α-bisabolol (1) against the etiological agents of visceral leishmaniasis. Bone-marrow-derived macrophages were infected with Leishmania infantum or L. donovani promastigotes and incubated with (−)-α-bisabolol at different concentrations. Pentamidine isethionate and meglumine antimoniate were used as reference drugs. Inhibitory concentration 50% (IC50) and cytotoxic concentration 50% (CC50) were calculated. Balb/c mice were infected intraperitoneally with stationary-phase promastigotes. They were treated with (−)-α-bisabolol at different doses orally, meglumine antimoniate at 104 mg SbV/kg, or a combination of both. (−)-α-Bisabolol proved to be innocuous to mammal cells and active against L. infantum and L. donovani intracellular amastigotes (IC50 55 and 39 μM, respectively). Compound 1 also proved to be active in an in vivo model of visceral leishmaniasis due to L. infantum, as it reduced parasite load in the spleen and li...

Journal ArticleDOI
TL;DR: The ELISAs provide a non-invasive method to detect parasite antigens during acute infection and monitor its clearance upon cure, filling an unmet need in VL management.
Abstract: Visceral leishmaniasis (VL) can be fatal without timely diagnosis and treatment. Treatment efficacies vary due to drug resistance, drug toxicity and co-morbidities. It is important to monitor treatment responsiveness to confirm cure and curtail relapse. Currently, microscopy of spleen, bone marrow or lymph node biopsies is the only definitive method to evaluate cure. A less invasive test for treatment success is a high priority for VL management. In this study, we describe the development of a capture ELISA based on detecting Leishmania donovani antigens in urine samples and comparison with the Leishmania Antigen ELISA, also developed for the same purpose. Both were developed as prototype kits and tested on patient urine samples from Sudan, Ethiopia, Bangladesh and Brazil, along with appropriate control samples from endemic and non-endemic regions. Sensitivity and specificity were assessed based on accurate detection of patients compared to control samples. One- Way ANOVA was used to assess the discrimination capacity of the tests and Cohen’s kappa was used to assess their correlation. The Leishmania Antigen Detect™ ELISA demonstrated >90 % sensitivity on VL patient samples from Sudan, Bangladesh and Ethiopia and 88 % on samples from Brazil. The Leishmania Antigen ELISA was comparable in performance except for lower sensitivity on Sudanese samples. Both were highly specific. To confirm utility in monitoring treatment, urine samples were collected from VL patients at days 0, 30 and 180 post- treatment. For the Leishmania Antigen Detect™ ELISA, positivity was high at day 0 at 95 %, falling to 21 % at day 30. At day 180, all samples were negative, corresponding well with clinical cure. A similar trend was also seen for the Leishmania Antigen ELISA albeit; with lower positivity of 91 % at Day 0 and more patients, remaining positive at Days 30 and 180. The Leishmania Antigen Detect™ and the Leishmania Antigen ELISAs are standardized, user- friendly, quantitative and direct tests to detect Leishmania during acute VL as well as to monitor parasite clearance during treatment. They are a clear improvement over existing options. The ELISAs provide a non-invasive method to detect parasite antigens during acute infection and monitor its clearance upon cure, filling an unmet need in VL management. Further refinement of the tests with more samples from endemic regions will define their utility in monitoring treatment.

12 Nov 2015
TL;DR: It is hypothesized that cellular immune responses to human VL are dichotomatous, and that IFN‐γ production and the LST response are not in a causal relationship.
Abstract: Healing/protective responses in human visceral leishmaniasis (VL) are associated with stimulation/production of Th1 cytokines, such as interferon IFN‐γ, and conversion in the leishmanin skin test (LST). Such responses were studied for 90 days in 44 adult healthy volunteers from VL non‐endemic areas, with no past history of VL/cutaneous leishmaniasis (CL) and LST non‐reactivity following injection with one of four doses of Alum‐precipitated autoclaved Leishmania major (Alum/ALM) ± bacille Calmette–Guérin (BCG), a VL candidate vaccine. The vaccine was well tolerated with minimal localized side‐effects and without an increase in antileishmanial antibodies or interleukin (IL)‐5. Five volunteers (5/44; 11·4%) had significant IFN‐γ production by peripheral blood mononuclear cells (PBMCs) in response to Leishmania antigens in their prevaccination samples (P = 0·001) but were LST non‐reactive. On day 45, more than half the volunteers (26/44; 59·0%) had significantly high LST indurations (mean 9·2 ± 2·7 mm) and high IFN‐γ levels (mean 1008 ± 395; median 1247 pg/ml). Five volunteers had significant L. donovani antigen‐induced IFN‐γ production (mean 873 ± 290; median 902; P = 0·001), but were non‐reactive in LST. An additional five volunteers (5/44; 11·4%) had low IFN‐γ levels (mean 110 ± 124 pg/ml; median 80) and were non‐reactive in LST (induration = 00 mm). The remaining eight volunteers had low IFN‐γ levels, but significant LST induration (mean 10 ± 2·9 mm; median 11). By day 90 the majority of volunteers (27/44; 61·4%) had significant LST induration (mean 10·8 ± 9·9 mm; P < 0·001), but low levels of L. donovani antigen‐induced IFN‐γ (mean 66·0 ± 62 pg/ml; P > 0.05). Eleven volunteers (11/44; 25%) had significantly high levels of IFN‐γ and LST induration, while five volunteers had low levels of IFN‐γ (<100 pg/ml) and no LST reactivity (00 mm). One volunteer was lost to follow‐up. In conclusion, it is hypothesized that cellular immune responses to human VL are dichotomatous, and that IFN‐γ production and the LST response are not in a causal relationship. Following vaccination and probably cure of VL infection, the IFN‐γ response declines with time while the LST response persists. LST is a simple test that can be used to assess candidate vaccine efficacy.