Leishmaniasis

Senna rugosa (Fabaceae) is a common specie of the Brazilian territory, especially in the Cerrado biome. It is widely used in the popular medicine although not yet adequately investigated as to its phytoconstituents and pharmacological activities. In this study, the preliminary phytochemical analysis of ethanolic leaf extract of S. rugosa was performed and its cytotoxicity, antitumoral and antimicrobial activities (antibacterial, antifungal, anti-Trypanosoma and anti-Leishmania) were evaluated. The crude extract was analyzed in HPLC-DAD and fractions were also characterized using GC-MS and ESI-MS techniques. Results indicate phenolic compounds majority presence, including flavonol, anthraquinone and anthrones derivatives. Relative antimicrobial activities were detected against Staphylococcus aureus, Pseudomonas aeruginosa, Candida famata, Candida krusei and Candida tropicalis. As well as, a weak anti-trypanosomatids activity against M2269 strain and BH46 strain of Leishmania sp. A re...

In Bangladesh, serological tests have been widely used for the primary screening of visceral leishmaniasis (VL). Several serologic tests are available for the diagnosis of VL. Selection of the best test is important to permit diagnostic differentiation between symptomatic and asymptomatic patients and to reduce cross-reactivity. We evaluated the effectiveness of a new serological test “Onsite Leishmania Ab Rapid Test” as a part of “quality assurance” activities for the kala azar elimination programme of the Government of Bangladesh. Plasma samples of 100 parasitologically confirmed cases of VL along with 101 healthy controls were tested, and “Onsite Leishmania Ab Rapid Test” strip tests were positive in 94 out of 100 confirmed VL cases, whereas four out of 51 healthy subjects from the VL endemic areas also tested positive. All the 50 healthy volunteers tested negative. Thus, the sensitivity and specificity of “Onsite Leishmania Ab Rapid Test” strip test were found to be 94% (95% CI:...

Para Kala-azar Dermal Leishmaniasis (Para-KDL) manifests the concomitant presence of Post Kala-azar Dermal Leishmaniasis and Visceral Leishmaniasis and works as a reservoir of infection. The study discusses the cases and their management and aims to address the gaps within existing methods of diagnosis and treatment. This retrospective cross-sectional study discusses 16 Para-KDL cases with one-year follow-up data, treated between 2012–2021 at the Surya Kanta Kala-azar Research Center, Bangladesh. We collected data from hospital records and used STATA 16 to analyze and see the frequency distribution and variable means. We found five patients without any history of kala-azar infection. All the patients were treated with 20 mg/kg Liposomal Amphotericin B in 4 divided doses except one with a history of AmBisome hypersensitivity. One year after treatment, all patients were free from skin lesions, with no hepatosplenomegaly, and observed significant improvement in BMI and hemoglobin level...

Despite the availability of highly sensitive polymerase chain reaction (PCR)-based methods, the dearth of remotely deployable diagnostic tools circumvents the early and accurate detection of individuals with post-kala-azar dermal leishmaniasis (PKDL). Here, we evaluate a design-locked loop-mediated isothermal amplification (LAMP) assay to diagnose PKDL. A total of 76 snip-skin samples collected from individuals with probable PKDL (clinical presentation and a positive rK39 rapid diagnostic test (RDT)) were assessed by microscopy, qPCR, and LAMP. An equal number of age and sex-matched healthy controls were included to determine the specificity of the LAMP assay. The LAMP assay with a Qiagen DNA extraction (Q-LAMP) showed a promising sensitivity of 72.37% (95% CI: 60.91–82.01%) for identifying the PKDL cases. LAMP assay sensitivity declined when the DNA was extracted using a boil-spin method. Q-qPCR showed 68.42% (56.75–78.61%) sensitivity, comparable to LAMP and with an excellent agre...

Background Asymptomatic Leishmania infections outnumber clinical infections on the Indian subcontinent (ISC), where disease reservoirs are anthroponotic. Diagnostics which detect active asymptomatic infection, which are suitable for monitoring and surveillance, may be of benefit to the visceral leishmaniasis (VL) elimination campaign on the ISC. Methods Quantitative polymerase chain reaction (qPCR), loop-mediated isothermal amplification (LAMP), and the direct agglutination test (DAT) were carried out on blood samples, and the Leishmania antigen ELISA was carried out on urine samples collected from 720 household and neighbouring contacts of 276 VL and post–kala-azar dermal leishmaniasis (PKDL) index cases, with no symptoms or history of VL or PKDL, in endemic regions of Bangladesh between September 2016 and March 2018. Results Of the 720 contacts of index cases, asymptomatic infection was detected in 69 (9.6%) participants by a combination of qPCR (1.0%), LAMP (2.1%), DAT (3.9%), an...

The 5th Post-Kala-Azar Dermal Leishmaniasis (PKDL) Consortium meeting brought together PKDL experts from all endemic areas to review and discuss existing and new data on PKDL. This report summarizes the presentations and discussions and provides the overall conclusions and recommendations.

BackgroundAsymptomatic Leishmania infections outnumber clinical infections on the Indian sub-continent (ISC) where disease reservoirs are anthroponotic. Diagnostics which detect active asymptomatic infection, which are suitable for monitoring and surveillance, may be of benefit to the visceral leishmaniasis (VL) elimination campaign on the ISC.Methodology/Principal FindingsQuantitative polymerase chain reaction (qPCR), loop mediated isothermal amplification (LAMP), the direct agglutination test (DAT), and the Leishmania antigen ELISA were carried out on blood and urine samples collected from 720 household and neighbouring contacts of 276 VL and post kala-azar dermal leishmaniasis (PKDL) index cases, with no symptoms or history of VL and PKDL, in endemic regions of Bangladesh between September 2016 and March 2018. Of the 720 contacts of index cases, asymptomatic infection was detected in 69 (9.6%) participants by a combination of qPCR (1.0%), LAMP (2.1%), DAT (3.9%), and Leishmania a...

Post-kala-azar dermal leishmaniasis (PKDL) is a sequel to visceral leishmaniasis (VL), which is found in VL-endemic countries including Bangladesh. Because of these enigmatic cases, the success of the National Kala-azar Elimination Program is under threat. To date, diagnostic methods for PKDL cases in endemic regions have been limited to clinical examination and rK39 test or microscopy, and a suitable and accurate alternative method is needed. In this study, we investigated the application of real-time polymerase chain reaction (PCR) as a potential method for diagnosis of PKDL in comparison with microscopy. Ninety-one suspected macular PKDL cases from Mymensingh district, Bangladesh, were enrolled in the study after diagnosis by clinical examination and an rK39 strip test. All of them responded after completion of the treatment with miltefosine. During enrollment, a skin biopsy was done for each patient, and both microscopy and real-time PCR were performed for detection and quantifi...

In the Indian subcontinent, visceral leishmaniasis (VL) incidence is on track to reach elimination goals by 2020 in nearly all endemic districts. Although not included in official targets, previous data suggest post-kala-azar dermal leishmaniasis (PKDL) patients can act as an infection reservoir. We conducted xenodiagnosis on 47 PKDL patients and 15 VL patients using laboratory-reared Phlebotomus argentipes. In direct xenodiagnosis, flies were allowed to feed on the patient's skin for 15 minutes. For indirect xenodiagnosis, flies were fed through a membrane on the patient's blood. Five days later, blood-fed flies were dissected and examined by microscopy and/or PCR. A 3-mm skin snip biopsy (PKDL) or venous blood VL) was processed by quantitative PCR. Twenty-seven PKDL patients (57.4%) had positive results by direct and/or indirect xenodiagnosis. Direct was significantly more sensitive than indirect xenodiagnosis (55.3% vs 6.4%, p <0.0001). Those with positive xenodiagnosi...

Post Kala-azar Dermal Leishmaniasis (PKDL) is a sequel of Visceral Leishmaniasis (VL). The patients act as a reservoir for the causative parasite (i.e. Leishmania donovani) and thus should be diagnosed and treated with the utmost urgency to prevent the transmission of the disease. In this study, we tried to report the first instances of corneal complications supposedly associated with Miltefosine (MF), in PKDL patients and the probable pathophysiology of such events. The recently rejuvenated National Kala-azar Elimination Program in Bangladesh has put great emphasis on monitoring all the leishmaniasis patients to investigate possible adverse drug reactions (ADR). A total of 194 patients have received Miltefosine for the treatment of Post Kala-azar Dermal Leishmaniasis. So far five patients were found to have developed unilateral ophthalmic complications during the periods from May 2016 to October 2017, after being treated with MF for PKDL. Unfortunately, one of whom had to go throug...

Post-kala-azar dermal leishmaniasis (PKDL) is a dermatological complication that occurs primarily among treated visceral leishmaniasis (VL) patients, and sporadically in a few without a history of VL. It mostly affects children and adolescents but is also common in adults. The conventional treatment with 120 intramuscular injections of sodium stibogluconate (SSG) is phasing out. Miltefosine (MF) is the only eventual alternative to SSG; however, its efficacy and safety profiles for treatment of children and adolescents with PKDL are lacking. In addition, risk factors for PKDL are poorly investigated. Host genetic, nutritional and environmental factors could be potential risk factors. As such, here we propose to evaluate the efficacy and safety of MF for 12 weeks at an allometric dose for children and adolescents with PKDL, and also to explore potential risk factors for PKDL. A cross-sectional survey will look for suspected participants with PKDL among treated VL children and adolesce...

New methods for controlling sand fly are highly desired by the Visceral Leishmaniasis (VL) elimination program of Bangladesh, India and Nepal for its consolidation and maintenance phases. To support the program we investigated safety, efficacy and cost of Durable Wall Lining to control sand fly. This multicentre randomized controlled study in Bangladesh, India and Nepal included randomized two intervention clusters and one control cluster. Each cluster had 50 households except full wall surface coverage (DWL-FWSC) cluster in Nepal which had 46 households. Ten of 50 households were randomly selected for entomological activities except India where it was 6 households. Interventions were DWL-FWSC and reduced wall surface coverage (DWL-RWSC) with DWL which covers 1.8 m and 1.5 m height from floor respectively. Efficacy was measured by reduction in sand fly density by intervention and sand fly mortality assessment by the WHO cone bioassay test at 1 month after intervention. Trained fiel...

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 t...

Post-kala-azar dermal leishmaniasis (PKDL) without previous visceral leishmaniasis (VL) is a rare dermatological manifestation of Leishmania infection. To date, most of the reported cases neither showed parasitological confirmation nor explained the outcome of treatment. Herein, we report three confirmed cases that were were successfully cured after miltefosine treatment.

BackgroundCutaneous Leishmaniasis (CL) is a neglected tropical disease, which mainly affects poor communities. It is one of the major vector-borne disease and endemic in Pakistan.MethodsA case-control study to evaluate potential risk factors of human-CL was conducted in Khewra region, District Jhelum, Pakistan from January–April 2014. Case data about 90 cases registered during October 2012 to November 2013 was retrieved from Municipal Hospital. Controls were matched (1,1 ratio) on the date of registration with cases from same hospital. Both cases and controls were invited to participate and data was collected in a face-to-face interview. A prospective study of canine leishmaniasis (canine-CL) was also conducted at Civil Veterinary Hospital in the same area. Suspected dogs with skin ulceration signs were included in the study and blood samples were collected. Statistical analyses were conducted to determine association between various parameters and outcome of interest.ResultsThe age...

Tegumentary leishmaniasis, a disease caused by protozoan parasites of the genus Leishmania, is a major public health problem in many regions of Latin America. Its diagnosis is difficult given other conditions resembling leishmaniasis lesions and co-occurring in the same endemic areas. A combination of parasitological and molecular methods lead to accurate diagnosis, with the latter being traditionally performed in centralized reference and research laboratories as they require specialized infrastructure and operators. CRISPR-Cas systems have recently driven innovative tools for nucleic acid detection that combine high specificity, sensitivity and speed and are readily adaptable for point-of-care testing. Here, we harnessed the CRISPR-Cas12a system for molecular detection of Leishmania spp., emphasizing medically relevant parasite species circulating in Peru and other endemic areas in Latin America, with L. (Viannia) braziliensis being the main etiologic agent of cutaneous and mucosa...

World Health Organization (WHO) identified twenty tropical disease categories as neglected tropical diseases (NTDs)1. Chagas’ disease (also known as American trypanosomiasis) and leishmaniasis are two major classes of NTDs. The total number of mortality, morbidity, and disability attributed each year due to these two categories of diseases in magnitudes is much higher than the so-called elite diseases like cancer, diabetes, AIDS, cardiovascular and neurodegenerative diseases. Impoverished communities around the world are the major victim of NTDs. The development of new and novel drugs in the battle against Chagas’ disease and leishmaniasis is highly anticipated. An easy and straightforward on-water green access to synthesize benzopyrazines is reported. This ultrasound-assisted procedure does not require any catalyst/support/additive/hazardous solvents and maintains a high atom economy. A series of eleven benzopyrazines has been synthesized, and most of the synthesized compounds poss...

A sensitive microcapillary culture method (MCM) was developed for rapid diagnosis of cutaneous leishmaniasis (CL). The MCM is superior to the traditional culture method (TCM) as determined by the smaller inoculum size, the higher sensitivity for detection of promastigotes, and the more rapid time for emergence of promastigotes. With lesion amastigote loads from grade III to 0, the positive rates and the periods for promastigote emergence were 3-4-fold higher and faster with the MCM than with the TCM, e.g., 83-97% positive in 4-7 days versus 20-40% positive in 15-30 days (P = 0.0001). The higher PCO 2 and lower Po 2 and pH presumably encourage a rapid amastigote-to-promastigote differentiation and/or the survival or growth of the latter. This MCM has the advantage of simplicity, and may be suitable for diagnostic use and for parasite retrieval in many other endemic sites where parasites are known to be difficult to grow.

In human cutaneous leishmaniasis (CL), the success of positive diagnoses and species identifications depends, primarily, on how biopsies are taken and then processed and examined. The efficiency of three methods of taking skin biopsies from suspect cases of CL was compared using the classical methods of microscopy of stained smears, in vitro culture of tissue aspirate, and internal transcribed spacer region 1 (ITS1)-polymerase chain reaction in diagnosing positive cases and identifying the species of Leishmania causing them. From 1994 to 2014, biopsy samples from the skin lesions of 2232 CL-suspected patients were collected as unstained smears, as smears stained with Giemsa's stain and on filter paper, and compared in the diagnostic tests employed. Matched comparison based on testing biopsy samples from 100 patients, microscopy, in vitro culture and ITS1-PCR were also conducted to assess the most suitable combination of methods for diagnosing leishmaniases. In the 100-case-match...