Influence of climate and river level on the incidence of malaria in Cacao, French Guiana

<p>Abstract</p> <p>Background</p> <p>The epidemiological profiles of vector-borne diseases, such as malaria, are strongly associated with environmental conditions. An understanding of the effect of the climate on the occurrence of malaria may provide indirect insight into the anopheles mosquito vectors endemic to a particular region. The association between meteorological and hydrographical factors and the occurrence of malaria was studied in a village in French Guiana during an epidemic caused essentially by <it>Plasmodium vivax</it>.</p> <p>Methods</p> <p>A cohort of confirmed cases of <it>P. vivax </it>malaria occurring between 2002 and 2007 was studied to search for an association between the number of new infection episodes occurring each month, mean, maximum and minimum monthly temperatures, cumulative rainfall for the month and the mean monthly height of the river bordering the village, with the aid of time series. Cross-correlation analysis revealed that these meteorological factors had large effects on the number of episodes, over a study period of 12 months.</p> <p>Results</p> <p>Climatic factors supporting the continuance of the epidemic were identified in the short-term (low minimum temperatures during the month), medium-term (low maximum temperatures two months before) and long-term (low maximum temperatures nine months before and high lowest level of the river 12 months before). Cross-correlation analysis showed that the effects of these factors were greatest at the beginning of the short rainy season.</p> <p>Conclusion</p> <p>The association between the river level and the number of malaria attacks provides clues to better understand the environment of malaria transmission and the ecological characteristics of the vectors in the region.</p

Specific antibody responses against membrane proteins of erythrocytes infected by Plasmodium falciparum of individuals briefly exposed to malaria

International audienceBACKGROUND: Plasmodium falciparum infections could lead to severe malaria, principally in non-immune individuals as children and travellers from countries exempted of malaria. Severe malaria is often associated with the sequestration of P. falciparum-infected erythrocytes in deep micro-vascular beds via interactions between host endothelial receptors and parasite ligands expressed on the surface of the infected erythrocyte. Although, serological responses from individuals living in endemic areas against proteins expressed at surface of the infected erythrocyte have been largely studied, seldom data are available about the specific targets of antibody response from travellers. METHODS: In order to characterize antigens recognized by traveller sera, a comparison of IgG immune response against membrane protein extracts from uninfected and P. falciparum-infected red blood cells (iRBC), using immunoblots, was performed between non exposed individuals (n = 31) and briefly exposed individuals (BEI) (n = 38) to malaria transmission. RESULTS: Immune profile analysis indicated that eight protein bands from iRBC were significantly detected more frequently in the BEI group. Some of these antigenic proteins were identified by an original immuno-proteomic approach. CONCLUSION: Collectively, these data may be useful to characterize the singular serological immune response against a primary malaria infection in individuals briefly exposed to transmission

IgG responses to the gSG6-P1 salivary peptide for evaluating human exposure to Anopheles bites in urban areas of Dakar region, Sénégal

<p>Abstract</p> <p>Background</p> <p>Urban malaria can be a serious public health problem in Africa. Human-landing catches of mosquitoes, a standard entomological method to assess human exposure to malaria vector bites, can lack sensitivity in areas where exposure is low. A simple and highly sensitive tool could be a complementary indicator for evaluating malaria exposure in such epidemiological contexts. The human antibody response to the specific <it>Anopheles </it>gSG6-P1 salivary peptide have been described as an adequate tool biomarker for a reliable assessment of human exposure level to <it>Anopheles </it>bites. The aim of this study was to use this biomarker to evaluate the human exposure to <it>Anopheles </it>mosquito bites in urban settings of Dakar (Senegal), one of the largest cities in West Africa, where <it>Anopheles </it>biting rates and malaria transmission are supposed to be low.</p> <p>Methods</p> <p>One cross-sectional study concerning 1,010 (505 households) children (n = 505) and adults (n = 505) living in 16 districts of downtown Dakar and its suburbs was performed from October to December 2008. The IgG responses to gSG6-P1 peptide have been assessed and compared to entomological data obtained in or near the same district.</p> <p>Results</p> <p>Considerable individual variations in anti-gSG6-P1 IgG levels were observed between and within districts. In spite of this individual heterogeneity, the median level of specific IgG and the percentage of immune responders differed significantly between districts. A positive and significant association was observed between the exposure levels to <it>Anopheles gambiae </it>bites, estimated by classical entomological methods, and the median IgG levels or the percentage of immune responders measuring the contact between human populations and <it>Anopheles </it>mosquitoes. Interestingly, immunological parameters seemed to better discriminate the exposure level to <it>Anopheles </it>bites between different exposure groups of districts.</p> <p>Conclusions</p> <p>Specific human IgG responses to gSG6-P1 peptide biomarker represent, at the population and individual levels, a credible new alternative tool to assess accurately the heterogeneity of exposure level to <it>Anopheles </it>bites and malaria risk in low urban transmission areas. The development of such biomarker tool would be particularly relevant for mapping and monitoring malaria risk and for measuring the efficiency of vector control strategies in these specific settings.</p

Hyperactivité et jeux vidéo (étude comparative entre une population d'enfants hyperactifs et une population d'enfants témoins)

L'objectif de cette thèse est d'une part de décrire les comportements des enfants hyperactifs face aux jeux vidéo et d'autre part de rechercher un lien éventuel entre le trouble hyperactivité avec déficit attentionnel (THADA) et l'addiction aux jeux vidéo. Il s'agit d'une étude portant sur 50 sujets, comparant deux populations d'enfants hyperactifs (n=29) et non hyperactifs (n=21). Les enfants ont rempli des questionnaires évaluant les problèmes associés aux jeux videéo (échelle Problem Video-game Playing) et la perception des troubles ; les parents ont rempli un questionnaire, élaboré pour cette étude, décrivant les modalité"s d'utilisation des jeux vidéo. Nous avons recueilli les caractéristiques cliniques et comportementales des enfants. Les enfants hyperactifs présentent davantage de problèmes associés aux jeux viséo, pouvant suggérer une dépendance. Leurs parents rapportent plus souvent des difficultés à obtenir l'interruption du jeu à l'initiative de l'enfant ou sur demande des parents, entraînant plus de sanctions parentales, des manifestations externalisées à l'arrêt du jeu ainsi que des perturbations des relations familiales. Notre étude ne nous a pas permis de dégager un profil à risque de développement d'une addiction aux jeux vidéo parmi la population THADA. Néanmoins, nous avons mis en évidence des caractéristiques cliniques différentes entre les enfants hyperactifs dits "dépendants" et "non dépendants", telles qu'un index d'hyperactivité plus sévère à l'échelle de Conners et des dimensions de comportements agressifs, de comportements délinquants et de troubles externalisés plus fréquents parmi les dépendants à l'échelle Child Behaviour Checklist.BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Phobie sociale et inhibition comportementale chez l'enfant et l'adolescent (étude clinique de validation de l'échelle d'anxiété sociale de Liebowitz)

BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Trouble déficit de l'attention/hyperactivité et nouvelles technologies de l'information et la communication (jeux vidéo, réalité virtuelle et performances)

Le trouble déficit de l attention/hyperactivité (TDA/H) pourrait être un facteur de vulnérabilité au jeu pathologique. Le développement des nouvelles technologies de l information et la communication a fait émerger de nouvelles problématiques en termes d excès d utilisation mais aussi ouvre de nouvelles perspectives en termes d évaluation. L objectif de cette thèse était d examiner les liens entre nouvelles technologies et TDA/H. Tout d abord, la question d un possible risque d addiction aux jeux vidéo en population TDA/H a été étudiée. Les sujets TDA/H ont présenté plus de problèmes associés aux jeux vidéo, en faveur de comportements addictifs concernant les jeux vidéo. Puis, un questionnement sur la notion de performances en situation de jeux vidéo est apparu. Les sujets TDA/H ont obtenu des performances identiques aux sujets témoins en situation de jeux vidéo. Ainsi, dans un contexte ludique, motivant et avec la présence de renforçateurs, les enfants TDA/H sont parvenus à mieux mobiliser leurs capacités attentionnelles. Enfin, s appuyant sur l attrait des enfants TDA/H pour les jeux vidéo, l intérêt de l utilisation d un logiciel de classe virtuelle a émergé. Les enfants TDA/H ont obtenu des performances significativement plus faibles comparées à des enfants témoins avec un déclin des performances au cours du temps chez les sujets TDA/H lors de la classe virtuelle. Pour conclure ce travail, nous avons proposé un modèle opérationnel du TDA/H s inspirant du modèle des ressources attentionnelles de Kahneman où les facteurs éveil, motivationnels, processus d inhibition et de renforcements viendraient moduler la capacité du processeur centralPARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Les phobies spécifiques de l'enfant et l'adolescent (étude préliminaire sur l'utilisation d'un nouvel outil dans le dépistage du trouble)

Les phobies spécifiques sont fréquentes mais de diagnostic difficile chez l'enfant et l'adolescent, du fait de la distinction parfois floue avec les peurs fondamentales normales, de particularités dans leur expression clinique et de l'absence d'outils de dépistage adaptés à cette pathologie. L'objectif de ce travail est de construire et évaluer un nouvel outil de dépistage des phobies spécifiques, dont l'originalité est de coupler la présentation de stimuli potentiellement phobogène au recueil parallèle de mesures subjectives et surtout objectives de l'anxiété. 32 sujets de 9 à 17 ans ont participé à l'étude et ont été répartis en 3 groupes (pathologie anxieuse, pathologie psychiatrique autre, groupe témoin). Sous ce format, l'outil ne permet pas de répondre au dépistage du trouble, limité par la mesure d'un paramètre physiologique unique. Néanmoins sont apparus des résultats intéressants en terme de faisabilité et tolérance. Il a permis de mettre en avant une certaine réactivité à des images choc, surtout dans le groupe des sujets anxieux. Le vecteur image et la forme du diaporama sont à discuter mais la mesure de données physiologiques, bien que complexe et n'ayant pas de critères de validité, reste une alternative intéressante dans le dépistage du trouble.Specific phobias are frequent but their diagnosis is hard to establish for kids and teenagers, due to the distinction -sometimes obscure- between those phobias and usual developmental fears, particularities in their clinical expression, or a lack of adapted tool to detect these pathologies. The aim of this piece of work is to build and test a new screening tool for specific phobias, the particularity of which is to tether the introduction of stimuli that can potentially trigger phobias, with the alternative collection of subjective and -above all- objective measures about anxiety. 32 people from 9 to 17 were tested for this piece of work and placed into 3 different groups (anxiety pathologies, other psychiatric pathologies and a testimony group). Under that pattern, this tool cannot test this precise kind of disorders, the tool being limited by the measurement of one single psychological parameter. Nevertheless, some results proved interesting, when it comes to feasibility and tolerance. It highlighted reactivity to striking images, especially among the anxiety pathologies group. The very use of images is still to be discussed, as well as the form of the slideshow, but the measurement of psychological data -be it complex and without any validity criterion- remains an interesting alternative for disorder screening.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

La phobie sociale chez l'enfant et l'adolescent (étude d'évaluation des groupes d'exposition et d'affirmation de soi)

BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Air Drep—A Retrospective Study Evaluating the Influence of Weather Conditions and Viral Epidemics on Vaso-Occlusive Crises in Patients with Sickle Cell Disease Living in French Guiana

(1) Objectives: French Guiana is the French territory most affected by sickle cell disease (SCD). This study investigates the associations between different environmental factors relative to climate, infectious outbreaks, and emergency visits or weekly hospital admissions for vaso-occlusive crisis (VOC). The identification of risk factors would lead to better patient care and patient management, and more targeted prevention and therapeutic education for patients with SCD in French Guiana. (2) Methods: This study was performed using data collected from the medicalized information system and emergency medical records of Cayenne General Hospital, between 1 January 2010 and 31 December 2016. ARIMA models were used to investigate the potential impact of weather conditions and flu epidemics on VOC occurrence. (3) Results: During the study period, 1739 emergency visits were recorded among 384 patients, of which 856 (49.2%) resulted in hospitalization, 811 (46.6%) resulted in hospital discharge, and 72 (4.2%) in another orientation. Decreased temperature and decreased humidity were both independent factors associated with an increase of VOC cases (p = 0.0128 and p = 0.0004, respectively). When studying severe VOC (leading to hospitalization, with or without prior emergency visit), 2104 hospital admissions were recorded for 326 patients. The only factor associated with severe VOC, in the multivariate analysis, was flu epidemics (p = 0.0148). (4) Conclusions: This study shows a link between climate, flu epidemics, and VOC in French Guiana. Patient&rsquo;s awareness of risks related to climate and flu epidemics should be encouraged, as home prevention measures can help avoid painful crises. Moreover, physicians should encourage patients to get immunized for influenza every year