Blood Parasite Load as an Early Marker to Predict Treatment Response in Visceral Leishmaniasis in Eastern Africa.

Background: To expedite the development of new oral treatment regimens for visceral leishmaniasis (VL), there is a need for early markers to evaluate treatment response and predict long-term outcomes.

Methods: Data from 3 clinical trials were combined in this study, in which Eastern African VL patients received various antileishmanial therapies. Leishmania kinetoplast DNA was quantified in whole blood with real-time quantitative polymerase chain reaction (qPCR) before, during, and up to 6 months after treatment.

Development and Evaluation of a Novel Loop-Mediated Isothermal Amplification Assay for Diagnosis of Cutaneous and Visceral Leishmaniasis.

A novel pan- loop-mediated isothermal amplification (LAMP) assay for the diagnosis of cutaneous and visceral leishmaniasis (CL and VL) that can be used in near-patient settings was developed. Primers were designed based on the 18S ribosomal DNA (rDNA) and the conserved region of minicircle kinetoplast DNA (kDNA), selected on the basis of high copy number. LAMP assays were evaluated for CL diagnosis in a prospective cohort trial of 105 patients in southwest Colombia.

Long-Term Storage of Cryptosporidium parvum for In Vitro Culture.

The long-term storage of Cryptosporidium life-cycle stages is a prerequisite for in vitro culture of the parasite. Cryptosporidium parvum oocysts, sporozoites, and intracellular forms inside infected host cells were stored for 6-12 mo in liquid nitrogen utilizing different cryoprotectants (dimethyl sulfoxide [DMSO], glycerol and fetal calf serum [FCS]), then cultured in vitro. Performance in vitro was quantified by estimating the total Cryptosporidium copy number with quantitative polymerase chain reaction (qPCR) in 3- and 7-day-old cultures.

An easy 'one tube' method to estimate viability of Cryptosporidium oocysts using real-time qPCR.

Viability estimation of the highly resistant oocysts of Cryptosporidium remains a key issue for the monitoring and control of this pathogen. We present here a simple 'one tube' quantitative PCR (qPCR) protocol for viability estimation using a DNA extraction protocol which preferentially solubilizes excysted sporozoites rather than oocysts. Parasite DNA released from excysted sporozoites was quantified by real-time qPCR using a ribosomal DNA marker.

Corrigendum to 'Duplex quantitative Reverse-Transcriptase PCR for simultaneous assessment of drug activity against intracellular amastigotes and their host cells' [Int. J. Parasitol. Drugs Drug Resist. 4 (2014) 14-19].

[This corrects the article DOI: 10.1016/j.ijpddr.

In vitro evaluation of traditionally used Surinamese medicinal plants for their potential anti-leishmanial efficacy.

Ethnopharmacological Relevance: Plant-based preparations are extensively used in Surinamese folk medicine for treating leishmaniasis, but often without a scientific rationale.

Aim Of The Study: To evaluate 25 Surinamese medicinal plants for their potential efficacy against leishmaniasis.

Materials And Methods: Concentrated plant extracts were evaluated for their effect on the viability of L.

Monitoring the response of patients with cutaneous leishmaniasis to treatment with pentamidine isethionate by quantitative real-time PCR, and identification of Leishmania parasites not responding to therapy.

Background: Leishmania (Viannia) guyanensis is believed to be the principal cause of cutaneous leishmaniasis (CL) in Suriname. This disease is treated with pentamidine isethionate (PI), but treatment failure has increasingly been reported.

Aim: To evaluate PI for its clinical efficacy, to compare parasite load, and to assess the possibility of treatment failure due to other infecting Leishmania species.

Quantitative analysis of Cryptosporidium growth in in vitro culture--the impact of parasite density on the success of infection.

Cryptosporidium is an important waterborne pathogen for which no treatment or vaccination is available. This study set out to quantify DNA replication of Cryptosporidium parvum in vitro. Cryptosporidium DNA could be detected at up to 60 % of input level in both host-cell-free and host cell containing cultures 6 days after infection with living sporozoites, but was lost within 2 days in cultures inoculated with UV-inactivated sporozoites.

Duplex quantitative Reverse-Transcriptase PCR for simultaneous assessment of drug activity against Leishmania intracellular amastigotes and their host cells.

Currently available drugs for treatment of Leishmania infections are highly toxic and drug resistance to first line therapies has been observed. New, safer and more effective drugs are urgently needed to improve clinical resolution of the disease and reduce the risks associated with it. High-throughput screening of new compounds against cultured promastigotes is easy to perform, but the results are poorly predictive of in vivo efficacy.

Safety and efficacy of single dose versus multiple doses of AmBisome for treatment of visceral leishmaniasis in eastern Africa: a randomised trial.

Background: Anti-leishmanial drug regimens that include a single dose AmBisome could be suitable for eastern African patients with symptomatic visceral leishmaniasis (VL) but the appropriate single dose is unknown.

Methodology: A multi-centre, open-label, non-inferiority, randomized controlled trial with an adaptive design, was conducted to compare the efficacy and safety of a single dose and multiple doses of AmBisome for the treatment of VL in eastern Africa. The primary efficacy endpoint was definitive cure (DC) at 6 months.

Simple colorimetric trypanothione reductase-based assay for high-throughput screening of drugs against Leishmania intracellular amastigotes.

Critical to the search for new anti-leishmanial drugs is the availability of high-throughput screening (HTS) methods to test chemical compounds against the relevant stage for pathogenesis, the intracellular amastigotes. Recent progress in automated microscopy and genetic recombination has produced powerful tools for drug discovery. Nevertheless, a simple and efficient test for measuring drug activity against Leishmania clinical isolates is lacking.

Development and evaluation of a loop-mediated isothermal amplification assay for rapid detection of Leishmania infantum in canine leishmaniasis based on cysteine protease B genes.

We developed a Leishmania infantum specific LAMP assay that was carried out using a set of, six primers targeting the cysteine protease B multi copy gene of L. infantum. Our result shows that we, successfully detect the L.

Leishmaniasis direct agglutination test: using pictorials as training materials to reduce inter-reader variability and improve accuracy.

Background: The Direct Agglutination Test (DAT) has a high diagnostic accuracy and remains, in some geographical areas, part of the diagnostic algorithm for Visceral Leishmaniasis (VL). However, subjective interpretation of results introduces potential for inter-reader variation. We report an assessment of inter-laboratory agreement and propose a pictorial-based approach to standardize reading of the DAT.

Dynamics of parasite clearance in cutaneous leishmaniasis patients treated with miltefosine.

Parasite loads were quantified in repeated skin biopsies from lesions of 2 patients with Old-World cutaneous leishmaniasis (CL) caused by Leishmania major and L. infantum during and after treatment with miltefosine. Miltefosine induced a rapid therapeutic effect on both infections with an initial decline of parasites of ∼1 log/week for the L.

Comparison of short-term and long-term protocols for stabilization and preservation of RNA and DNA of Leishmania, Trypanosoma, and Plasmodium.

Molecular tools continue to be important in the prevention and control of parasitic diseases. However, using these techniques directly in the field remains a major challenge. Therefore, the preservation of clinical samples collected from endemic field areas for later analysis remains an important preanalytical process.

Diagnostic accuracy of the Leishmania OligoC-TesT and NASBA-Oligochromatography for diagnosis of leishmaniasis in Sudan.

Background: The Leishmania OligoC-TesT and NASBA-Oligochromatography (OC) were recently developed for simplified and standardised molecular detection of Leishmania parasites in clinical specimens. We here present the phase II evaluation of both tests for diagnosis of visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and post kala-azar dermal leishmaniasis (PKDL) in Sudan.

Methodology: The diagnostic accuracy of the tests was evaluated on 90 confirmed and 90 suspected VL cases, 7 confirmed and 8 suspected CL cases, 2 confirmed PKDL cases and 50 healthy endemic controls from Gedarif state and Khartoum state in Sudan.

Phase II evaluation of sensitivity and specificity of PCR and NASBA followed by oligochromatography for diagnosis of human African trypanosomiasis in clinical samples from D.R. Congo and Uganda.

Background: The polymerase chain reaction (PCR) and nucleic acid sequence-based amplification (NASBA) have been recently modified by coupling to oligochromatography (OC) for easy and fast visualisation of products. In this study we evaluate the sensitivity and specificity of the PCR-OC and NASBA-OC for diagnosis of Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense human African trypanosomiasis (HAT).

Methodology And Results: Both tests were evaluated in a case-control design on 143 HAT patients and 187 endemic controls from the Democratic Republic of Congo (DRC) and Uganda.

Accordance and concordance of PCR and NASBA followed by oligochromatography for the molecular diagnosis of Trypanosoma brucei and Leishmania.

Objective: To evaluate the repeatability and reproducibility of four simplified molecular assays for the diagnosis of Trypanosoma brucei spp. or Leishmania ssp. in a multicentre ring trial with seven participating laboratories.

Sensitivity and specificity of the Leishmania OligoC-TesT and NASBA-oligochromatography for diagnosis of visceral leishmaniasis in Kenya.

Objective: To estimate the sensitivity and specificity of the OligoC-TesT and nucleic acid sequence-based amplification coupled to oligochromatography (NASBA-OC) for molecular detection of Leishmania in blood from patients with confirmed visceral leishmaniasis (VL) and healthy endemic controls from Kenya.

Methods: Blood specimens of 84 patients with confirmed VL and 98 endemic healthy controls from Baringo district in Kenya were submitted to both assays.

Results: The Leishmania OligoC-TesT showed a sensitivity of 96.

Development of a reverse transcriptase loop-mediated isothermal amplification (LAMP) assay for the sensitive detection of Leishmania parasites in clinical samples.

Here we describe a generic, reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) assay, for the identification of Leishmania species from clinical samples. LAMP is an isothermal reaction recently developed as a point-of-care diagnostic tool. Primers were designed in the conserved region of the 18S ribosomal RNA (rRNA) gene; amplification was visualized by the pre-amplification addition of fluorescent detection reagent (FDR) and a simple UV lamp.

Simplified molecular detection of Leishmania parasites in various clinical samples from patients with leishmaniasis.

Background: Molecular methods to detect Leishmania parasites are considered specific and sensitive, but often not applied in endemic areas of developing countries due to technical complexity. In the present study isothermal, nucleic acid sequence based amplification (NASBA) was coupled to oligochromatography (OC) to develop a simplified detection method for the diagnosis of leishmaniasis. NASBA-OC, detecting Leishmania RNA, was evaluated using clinical samples from visceral leishmaniasis patients from East Africa (n = 30) and cutaneous leishmaniasis from South America (n = 70) and appropriate control samples.

Nucleic acid sequence-based amplification with oligochromatography for detection of Trypanosoma brucei in clinical samples.

Molecular tools, such as real-time nucleic acid sequence-based amplification (NASBA) and PCR, have been developed to detect Trypanosoma brucei parasites in blood for the diagnosis of human African trypanosomiasis (HAT). Despite good sensitivity, these techniques are not implemented in HAT control programs due to the high cost of the equipment, which is unaffordable for laboratories in developing countries where HAT is endemic. In this study, a simplified technique, oligochromatography (OC), was developed for the detection of amplification products of T.

Detection of Trypanosoma brucei parasites in blood samples using real-time nucleic acid sequence-based amplification.

Currently, the conventional diagnosis of human African trypanosomiasis (HAT) is by microscopic demonstration of trypomastigotes in blood, lymph, and/or cerebrospinal fluid. However, microscopic diagnosis of HAT is not sensitive enough and may give false-negative results, thus, denying the patient the necessary treatment of the otherwise fatal disease. For this reason, a highly sensitive technique needs to be developed to enhance case findings.