Publications by authors named "Dujardin J"

Background: PCR has evolved into one of the most promising tools for T. cruzi detection in the diagnosis and control of Chagas disease. However, general use of the technique is hampered by its complexity and the lack of standardization.

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Leishmania species of the subgenus Viannia and especially Leishmania braziliensis are responsible for a large proportion of New World leishmaniasis cases. The reproductive mode of Leishmania species has often been assumed to be predominantly clonal, but remains unsettled. We have investigated the genetic polymorphism at 12 microsatellite loci on 124 human strains of Leishmania braziliensis from 2 countries, Peru and Bolivia.

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Introduction: The analysis of the PCR-restriction fragment length polymorphism and random amplified polymorphic DNA have been useful tools for Leishmania identification.

Objectives: Molecular procedures were demonstrated for identification and typing of reference strains of New World Leishmania and their applicability was validated for clinical samples.

Materials And Methods: DNA was extracted from 16 reference strains of Latin American Leishmania as well as from clinical samples of leishmaniasis patients.

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The leishmaniases are protozoan, zoonotic diseases transmitted to human and other mammal hosts by the bite of phlebotomine sandflies. Bolivia has the highest incidence of cutaneous leishmaniasis (CL) in Latin America (LA), with 33 cases per 100,000 population reported in 2006. CL is endemic in seven of the country's nine administrative departments.

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Monitoring Leishmania infection in sand flies is important for understanding the eco-epidemiology of kala-azar and assessing the impact of the recently launched kala-azar control programme in the Indian subcontinent. We applied a PCR technique that targets rRNA genes to estimate the natural incidence of Leishmania infection in sand flies sampled in six villages of the Terai region of Nepal. Amplifications were made on 135 pools of sand flies and confirmed by sequencing.

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The mechanisms linking the immune response to cutaneous and mucosal leishmaniasis (CL and ML, respectively) lesions and the response to treatment are incompletely understood. Our aims were to prospectively assess, by quantitative reverse transcription-PCR, the levels of mRNA for gamma interferon, tumor necrosis factor alpha, interleukin-10 (IL-10), IL-4, and IL-13, as well as the presence of T cells (CD2) and macrophages (CD68), in CL and ML lesions and to follow their changes in response to treatment with pentavalent antimonials. The leishmanin skin test (LST) was performed on all CL and ML patients before treatment.

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Objective: To compare a PCR assay and direct agglutination test (DAT) for the detection of potential markers of Leishmania infection in 231 healthy subjects living in a kala-azar endemic focus of Nepal.

Methods: The sample was composed of 184 (80%) persons without any known history of KA and not living in the same house as known kala-azar cases (HNK), 24 (10%) Healthy Household Contacts (HHC) and 23 (10%) past kala-azar cases which had been successfully treated (HPK).

Results: PCR and DAT positivity scores were, respectively: HNK, 17.

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All known significant insect vectors of Trypanosoma cruzi are members of the Reduviidae, subfamily Triatominae. Infections with this parasite are the cause of Chagas disease, the single most costly parasitic disease in the Western Hemisphere. The Triatominae are almost completely restricted to the Americas, with >130 species distributed in several foci of species richness and endemism; nevertheless, the processes involved in the diversification of this group remain poorly understood.

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We review and discuss here the specificity and contribution of genome (re-)arrangement studies for the exploration of genetic diversity among Leishmania. We show how the early molecular karyotyping studies generated an original perception of the genetics and evolution of these Protozoa, while providing some possible explanations on the parasite diverse phenotypes (drug resistance, pathogenicity..

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We used the cysteine proteinase B (cpb) gene family of the trypanosomatid genus Leishmania as a target to develop rapid, specific, and easy-to-use polymerase chain reaction (PCR) tests to discriminate Leishmania infantum, Leishmania donovani, Leishmania tropica, Leishmania aethiopica, and Leishmania major. Identification of all 5 Old World species and validation of intraspecies variability are features lacking in other species-specific PCRs. Amplicon analysis was done on agarose gels and was further simplified by using an oligochromatography dipstick to detect L.

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Rhodnius pallescens Barber 1932 is a silvatic species of Triatominae living in palm trees in Colombia and part of Central America. In Colombia, the species did not adapt to domestic structures and is not considered as an important vector for humans. In Panama, Costa Rica and Nicaragua it is a recognized vector adapting to peridomestic and domestic structures.

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Many species of Triatominae show evidence for morphological plasticity. Frequent taxonomic questions arose from this variability leading to disputes about describing new subspecies, species or even genera. We suggest this phenotypic flexibility is primarily an intraspecific feature, but with potential for evolutionary changes.

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In this population genetic study of Leishmania donovani parasites in the Indian subcontinent, 132 isolates obtained from patients in Bangladesh, India, Nepal and Sri Lanka suffering from Kala-azar (100), post-Kala-azar dermal leishmaniasis (PKDL) (25) and cutaneous leishmaniasis (CL) (2), and from 5 patients whose clinical patterns were not defined, were analysed by using 15 hyper-variable microsatellite loci. Multilocus microsatellite typing (MLMT) data were analysed by using a Bayesian model-based clustering algorithm and constructing phylogenic tree based on genetic distances. In total, 125 strains from Bangladesh, Bihar (India) and Nepal formed a very homogeneous population regardless of geographical origin, clinical manifestation, and whether they presented in vitro or in vivo susceptibility to antimonial drugs.

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Morphometrics underwent a revolution more than one decade ago. In the modern morphometrics, the estimate of size is now contained in a single variable reflecting variation in many directions, as many as there are landmarks under study, and shape is defined as their relative positions after correcting for size, position and orientation. With these informative data, and the corresponding software freely available to conduct complex analyses, significant biological and epidemiological features can be quantified more accurately.

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Background: Definite diagnosis of Leishmania infections is based on demonstration of the parasite by microscopic analysis of tissue biopsy specimens or aspirate samples. However, microscopy generally shows low sensitivity and requires invasive sampling.

Methods: We describe here the development of a simple and rapid test for the detection of polymerase chain reaction-amplified Leishmania DNA.

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Objective: To develop a new PCR for Leishmania detection and to estimate its diagnostic accuracy in a visceral leishmaniasis (VL) endemic area.

Methods: After providing the proof-of-concept, the diagnostic accuracy was estimated on blood from 247 non-endemic control persons and on blood and bone marrow from 173 confirmed VL, 39 probable VL and 87 non-VL patients from south-eastern Nepal.

Results: The PCR showed a specificity of 99.

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Until the early 1990s, pentavalent antimony was the only documented first-line drug employed for the treatment of zoonotic visceral leishmaniasis (VL) in the Mediterranean, with reported cure rates exceeding 95% in immunocompetent patients. The emergence of antimony resistance in other endemic settings and the increase in drug options have stimulated re-evaluation of the current therapeutic approaches and outcomes in Mediterranean countries. A scientific consortium ('LeishMed' network) collected updated information from collaborating clinical health centres of 11 endemic countries of Southern Europe, Northern Africa and the Middle East.

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Trypanosoma cruzi, the agent of Chagas disease is associated with a very high clinical and epidemiological pleomorphism. This might be better understood through studies on the evolutionary history of the parasite. We explored here the value of antigen genes for the understanding of the evolution within T.

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It is rare to observe right ventricular infarction caused by isolated right ventricular branch occlusion. Isolated right ventricular infarction accounts for less than three percent of all cases of infarction. Generally, it is associated with occlusion of a non dominant right coronary artery or of a right ventricular branch.

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The risk for reintroduction of some exotic vector-borne diseases in Europe has become a hot topic, while the reality of others is neglected at the public health policy level. Leishmaniasis is endemic in all southern countries of Europe, with approximately 700 autochthonous human cases reported each year (3,950 if Turkey is included). Asymptomatic cases have been estimated at 30-100/1 symptomatic case, and leishmaniasis has up to 25% seroprevalence in domestic dogs.

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Visceral leishmaniasis (VL) is a deadly vector-borne disease that causes an estimated 500 000 new cases a year. In India, Nepal and Bangladesh, VL is caused by Leishmania donovani, which is transmitted from man to man by the sandfly Phlebotomus argentipes. In 2005, these three countries signed a memorandum of understanding to eliminate VL from the region.

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Background: Among Chagas disease triatomine vectors, the largest genus, Triatoma, includes species of high public health interest. Triatoma dimidiata, the main vector throughout Central America and up to Ecuador, presents extensive phenotypic, genotypic, and behavioral diversity in sylvatic, peridomestic and domestic habitats, and non-domiciliated populations acting as reinfestation sources. DNA sequence analyses, phylogenetic reconstruction methods, and genetic variation approaches are combined to investigate the haplotype profiling, genetic polymorphism, phylogeography, and evolutionary trends of T.

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In recent years, new methods have been developed for the molecular typing of Leishmania that need to be extensively validated by studies of clinical isolates in a well defined epidemiological context. The present study is a contribution to this effort. Using PCR-RFLP of gp63 and cpb genes, we analysed 59 isolates of L.

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Background: Sulphadoxine-pyrimethamine has been abandoned as first- or second-line treatment by most African malaria endemic countries in favour of artemisinin-based combination treatments, but the drug is still used as intermittent preventive treatment during pregnancy. However, resistance to sulphadoxine-pyrimethamine has been increasing in the past few years and, although the link between molecular markers and treatment failure has not been firmly established, at least for pregnant women, it is important to monitor such markers.

Methods: This paper reports a novel sensitive, semi-quantitative and specific real-time PCR and melting curve analysis (MCA) assay using fluorescence resonance energy transfer (FRET) for the detection of DHPS-540, an important predictor for SP resistance.

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Molecular tools are used increasingly for descriptive epidemiological studies in different Mediterranean foci of visceral and cutaneous leishmaniases. Several molecular markers with different resolution levels have been developed to address key epidemiological questions related to the (re-)emergence and spread of leishmaniases, as well as its risk factors: environmental changes, immunosuppression and treatment failure. Typing and analytical tools are improving but are not yet addressing all epidemiological issues satisfactorily.

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