Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
ISSN: 0066-4804

pasteur-00590987
https://hal-riip.archives-ouvertes.fr/pasteur-00590987
DOI : 10.1128/AAC.01532-06
PUBMED : 17438062

Éditeur(s) : HAL CCSD Centers for Disease Control and Prevention
Résumé : International audience
To assess the prevalence of malaria among illegal gold miners in the French Guiana rainforest, we screened 205 miners during May-June 2014. Malaria prevalence was 48.3%; 48.5% of cases were asymptomatic. Patients reported self-medication with artemisinin-based combination therapy. Risk for emergence and spread of artemisinin resistance among gold miners in the rainforest is high.
ISSN: 1080-6040

Droits : http://creativecommons.org/licenses/by/
pasteur-01305106
https://hal-pasteur.archives-ouvertes.fr/pasteur-01305106
https://hal-pasteur.archives-ouvertes.fr/pasteur-01305106/document
https://hal-pasteur.archives-ouvertes.fr/pasteur-01305106/file/15-1957.pdf
DOI : 10.3201/eid2205.151957.

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: The genetic diversity of Plasmodium falciparum has been extensively studied in various parts of the world. However, limited data are available from Mauritania. The present study examined and compared the genetic diversity of P. falciparum isolates in Mauritania. METHODS: Plasmodium falciparum isolates blood samples were collected from 113 patients attending health facilities in Nouakchott and Hodh El Gharbi regions. K1, Mad20 and RO33 allelic family of msp-1 gene were determined by nested PCR amplification. RESULTS: K1 family was the predominant allelic type carried alone or in association with Ro33 and Mad20 types (90%; 102/113). Out of the 113 P. falciparum samples, 93(82.3%) harboured more than one parasite genotype. The overall multiplicity of infection was 3.2 genotypes per infection. There was no significant correlation between multiplicity of infection and age of patients. A significant increase of multiplicity of infection was correlated with parasite densities. CONCLUSIONS: The polymorphism of P. falciparum populations from Mauritania was high. Infection with multiple P. falciparum clones was observed, as well as a high multiplicity of infection reflecting both the high endemicity level and malaria transmission in Mauritania.
ISSN: 1475-2875

inserm-00936407
http://www.hal.inserm.fr/inserm-00936407
http://www.hal.inserm.fr/inserm-00936407/document
http://www.hal.inserm.fr/inserm-00936407/file/1475-2875-13-26.pdf
DOI : 10.1186/1475-2875-13-26

Éditeur(s) : HAL CCSD American Society of Tropical Medicine and Hygiene
Résumé : International audience
From September 2013 to July 2014, several gold miners working in the tropical forest consulted the Maripasoula Health Center in French Guiana for edema and findings consistent with right cardiac failure. Of the 42 cases of beriberi that were diagnosed, one patient died. The laboratory and clinical investigation demonstrated vitamin B1 deficiency in most of the patients tested. Furthermore, 30 of 42 patients responded favorably to 500 mg of intravenous or intramuscular thiamine supplementation. In addition, dietary investigation showed insufficient thiamine intake in these patients. We concluded that patients had acquired beriberi because of diet restrictions, hard labor, and infectious diseases, notably malaria. In 2016, cases were still being reported. We recommend screening for compatible symptoms in gold miners, thiamine supplementation, and nutritional intervention
ISSN: 0002-9637

inserm-01503899
http://www.hal.inserm.fr/inserm-01503899
http://www.hal.inserm.fr/inserm-01503899/document
http://www.hal.inserm.fr/inserm-01503899/file/2017%2C%20Mosnier%20-%20A%20Large%20Outbreak%20of%20Thiamine%20Deficiency%20among%20Illegal%20Gold%20Miners%20in%20French%20Guiana.pdf
DOI : 10.4269/ajtmh.15-0906

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : National audience
Contexte La qualité de l’air ambiant dans les enceintes de transports ferroviaires souterrains (EFS) est caractérisée par des particules en suspension riches en métaux, majoritairement du fer, et en carbone, dont la concentration massique est très supérieure à celle mesurée dans l’air ambiant extérieur aux EFS. Cependant, les risques sanitaires chez les travailleurs des EFS liés aux polluants chimiques de l’air présents dans ces enceintes ferroviaires ont été peu étudiés. Dans ce contexte, l’Anses a été saisie afin de dresser un état des connaissances et réaliser une évaluation des risques sanitaires (ERS) chez les travailleurs des EFS. Méthodes Un groupe de travail pluridisciplinaire a analysé les études publiées jusqu’en décembre 2014 et des données communiquées par les exploitants de transport. L’ERS a porté sur les travailleurs de l’exploitation, l’organisation du transport et des services, et des commerces qui exercent une activité durant les horaires de trafic des rames de voyageurs. L’exposition chronique des travailleurs a été estimée à partir des données de concentration inhalée en particules (PM2,5 et PM10), en éléments métalliques, en carbone, en hydrocarbures aromatiques polycycliques particulaires et en hydrocarbures aromatiques monocycliques, issues d’une campagne transversale de métrologie individuelle de la RATP. Cette exposition estimée a ensuite été comparée à une valeur toxicologique de référence (VTR ajustée, VLEP, NOAECHEC) pour calculer un indicateur de risque. Résultats Les risques sanitaires en lien avec les éléments métalliques évalués individuellement semblent négligeables. Concernant l’exposition chronique aux particules, une inflammation des voies respiratoires et des effets consécutifs à cette inflammation sont probables, sur la base d’un effet démontré par une étude de toxicité aiguë chez l’animal. Par analogie avec les particules de l’air ambiant extérieur, des effets délétères sont attendus sur la santé cardiovasculaire et respiratoire en lien avec l’exposition chronique de ces travailleurs aux particules des EFS. L’ERS présente néanmoins des incertitudes notables compte tenu notamment du corpus d’études épidémiologiques assez peu informatif et de l’absence d’étude toxicologique d’exposition chronique. Conclusion Des effets sanitaires sont attendus en relation avec l’exposition chronique des travailleurs à la pollution de l’air des EFS. Des travaux sont recommandés pour combler les lacunes des connaissances sur la toxicité à long terme des particules de l’air de ces enceintes ferroviaires, mais également sur l’exposition de certaines catégories de travailleurs de la maintenance vraisemblablement plus exposés
ISSN: 1775-8785

hal-01331986
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01331986
DOI : 10.1016/j.admp.2016.03.448
PUBMED : 26334607

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
A major requirement for malaria elimination is the development of transmission-blocking interventions. In vitro transmission-blocking bioassays currently mostly rely on the use of very few Plasmodium falciparum reference laboratory strains isolated decades ago. To fill a piece of the gap between laboratory experimental models and natural systems, the purpose of this work was to determine if culture-adapted field isolates of P. falciparum are suitable for in vitro transmission-blocking bioassays targeting functional maturity of male gametocytes: exflagellation. Plasmodium falciparum isolates were adapted to in vitro culture before being used for in vitro gametocyte production. Maturation was assessed by microscopic observation of gametocyte morphology over time of culture and the functional viability of male gametocytes was assessed by microscopic counting of exflagellating gametocytes. Suitability for in vitro exflagellation-blocking bioassays was determined using dihydroartemisinin and methylene blue. In vitro gametocyte production was achieved using two isolates from French Guiana and two isolates from Cambodia. Functional maturity of male gametocytes was assessed by exflagellation observations and all four isolates could be used in exflagellation-blocking bioassays with adequate response to methylene blue and dihydroartemisinin. This work shows that in vitro culture-adapted P. falciparum field isolates of different genetic background, from South America and Southeast Asia, can successfully be used for bioassays targeting the male gametocyte to gamete transition, exflagellation.
ISSN: 1475-2875

Droits : http://creativecommons.org/licenses/by/
pasteur-01182753
https://hal-pasteur.archives-ouvertes.fr/pasteur-01182753
https://hal-pasteur.archives-ouvertes.fr/pasteur-01182753/document
https://hal-pasteur.archives-ouvertes.fr/pasteur-01182753/file/LeBas%20et%202015%20version%20publie%20%281%29.pdf
DOI : 10.1186/s12936-015-0752-x

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The present study investigated cerebral and muscle hemoglobin oxygen saturation (tissue oxygen index, TOI) in children with sickle cell anemia (SS), sickle cell hemoglobin C disease (SC) and healthy children (AA). TOI was measured by near-infrared spectroscopy (NIRS) and spectral analysis of the TOI variability was used to assess flowmotion and vasomotion. Arterial oxyhemoglobin saturation (SpO2), hemorheological and hematological parameters were also measured in SS and SC children. Both TOI were lower in SS compared to both AA and SC children, with SC exhibiting lower values than AA children. Cerebral vasomotion expressed in absolute values was enhanced in SS compared to AA and SC children. Muscle vasomotion did not differ between the three groups. Hematocrit, SpO2 and red blood cell deformability were positively associated with cerebral TOI in SS children. We demonstrated that 1) cerebral and muscle TOI were markedly decreased in SS children while the decrease of TOI was milder in SC children, 2) cerebral TOI level was associated with several biological markers in SS children only and 3) cerebral vasomotion was enhanced in SS, possibly to counterbalance the effects of chronic cerebral hypoxia.
ISSN: 1079-9796

inserm-01519106
http://www.hal.inserm.fr/inserm-01519106
http://www.hal.inserm.fr/inserm-01519106/document
http://www.hal.inserm.fr/inserm-01519106/file/2017%2C%20Charlot%20-%20Cerebral%20and%20muscle%20microvascular%20oxygenation%20in%20children%20with%20sickle%20celle%20disease.pdf
DOI : 10.1016/j.bcmd.2017.03.015

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Local variation in the density of Anopheles mosquitoes and the risk of exposure to bites are essential to explain the spatial and temporal heterogeneities in the transmission of malaria. Vector distribution is driven by environmental factors. Based on variables derived from satellite imagery and meteorological observations, this study aimed to dynamically model and map the densities of Anopheles darlingi in the municipality of Saint-Georges de l’Oyapock (French Guiana). Longitudinal sampling sessions of An. darlingi densities were conducted between September 2012 and October 2014. Landscape and meteorological data were collected and processed to extract a panel of variables that were potentially related to An. darlingi ecology. Based on these data, a robust methodology was formed to estimate a statistical predictive model of the spatial-temporal variations in the densities of An. darlingi in Saint-Georges de l’Oyapock. The final cross-validated model integrated two landscape variables—dense forest surface and built surface—together with four meteorological variables related to rainfall, evapotranspiration, and the minimal and maximal temperatures. Extrapolation of the model allowed the generation of predictive weekly maps of An. darlingi densities at a resolution of 10-m. Our results supported the use of satellite imagery and meteorological data to predict malaria vector densities. Such fine-scale modeling approach might be a useful tool for health authorities to plan control strategies and social communication in a cost-effective, targeted, and timely manner.
ISSN: 1932-6203

hal-01383486
https://hal.archives-ouvertes.fr/hal-01383486
https://hal.archives-ouvertes.fr/hal-01383486/document
https://hal.archives-ouvertes.fr/hal-01383486/file/Adde_et_al_PlosONE_2016.pdf
DOI : 10.1371/journal.pone.0164685

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
Human leishmaniasis are widely spread diseases with different clinical forms caused by about 20 species within the Leishmania genus. Leishmania species identification is relevant for therapeutic management and prognosis, especially for cutaneous and muco-cutaneous forms. Several methods are available to identify Leishmania species from culture, but they have not been standardized for the majority of the currently described species, with the exception of MultiLocus Enzyme Electrophoresis. Moreover, these techniques are expensive, time-consuming and not available in all laboratories. Within the last decade, mass spectrometry (MS) has been adapted for microorganism identification, including Leishmania However, no commercial reference mass spectral database is available. In this study, a reference mass spectral library (MSL) for Leishmania isolates, accessible through a free web-based application (mass spectral identification, MSI), was constructed and tested. It includes mass spectral data for 33 different Leishmania species, including species that infect humans, animals and phlebotomine vectors. Four laboratories on two continents evaluated MSI performance using 268 samples of which 231 were Leishmania strains. All Leishmania strains, but one, were correctly identified at least at the complex level. A risk of species misidentification within the L. donovani, L. guyanensis and L. braziliensis complexes was observed, as already reported with other techniques. The tested application was reliable, with identification results comparable to those obtained with reference methods, but with a more favorable cost-efficiency ratio. This free online identification system relies on a scalable database and can be implemented directly in the user's computers.
ISSN: 0095-1137

hal-01571305
https://hal.archives-ouvertes.fr/hal-01571305
DOI : 10.1128/JCM.00845-17
PUBMED : 28724559

Éditeur(s) : HAL CCSD
Résumé : International audience
In French Guiana, located on the northeastern coast of South America, bats of different species are very numerous. The infection of bats and their ticks with zoonotic bacteria, especially Rickettsia species, is so far unknown. In order to improve knowledge of these zoonotic pathogens in this French overseas department, the presence and diversity of tick-borne bacteria was investigated with molecular tools in bat ticks. In the beginning of 2013, 32 bats were caught in Saint-Jean-du-Maroni, an area close to the coast of French Guiana, and the ticks of these animals were collected. A total of 354 larvae of Argasidae soft ticks (Ornithodoros hasei) from 12 bats (Noctilio albiventris) were collected and 107 of them were analysed. DNA was extracted from the samples and quantitative real-time PCR was carried out to detect Rickettsia spp., Bartonella spp., Borrelia spp. and Coxiella burnetii. All tested samples were negative for Bartonella spp., Borrelia spp. and Coxiella burnetii. Rickettsia DNA was detected in 31 (28.9%) ticks. An almost entire (1118 base pairs long) sequence of the gltA gene was obtained after the amplification of some positive samples on conventional PCR and sequencing. A Bayesian tree was constructed using concatenated rrs, gltA, ompA, ompB, and gene D sequences. The study of characteristic sequences shows that this Rickettsia species is very close (98.3-99.8%) genetically to R. peacockii. Nevertheless, the comparative analysis of sequences obtained from gltA, ompA, ompB, rrs and gene D fragments demonstrated that this Rickettsia is different from the other members of the spotted fever group. The sequences of this new species were deposited in GenBank as Candidatus Rickettsia wissemanii. This is the first report showing the presence of nucleic acid of Rickettsia in Ornithodoros hasei ticks from South American bats. (C) 2016 Elsevier GmbH. All rights reserved.
TICKS AND TICK-BORNE DISEASES

hal-01459758
https://hal.archives-ouvertes.fr/hal-01459758
DOI : 10.1016/j.ttbdis.2016.09.004

Éditeur(s) : HAL CCSD Mary Ann Liebert
Résumé : International audience
We screened blood from 59 bats from French Guiana for Bartonella spp. PCRs were positive for 13.6% and culture was positive in one Noctilio albiventris and one Pteronotus parnellii, as well as in Ornithodoros hasei ticks collected from bats. Two isolated strains represent possible two new species.
ISSN: 1530-3667

hal-01455597
https://hal.archives-ouvertes.fr/hal-01455597
DOI : 10.1089/vbz.2015.1918