Trouble de stress post-traumatique chez des travailleurs humanitaires de retour de mission : vers une meilleure identification des facteurs de risque et de protection

La profession de travailleur humanitaire (TH) consiste à fournir une assistance à des populations en difficulté lors de crises humanitaires. La littérature suggère que ces travailleurs, qui évoluent dans des environnements complexes, sont exposés à diverses sources de stress, incluant des événements potentiellement traumatiques (ÉPT). Par conséquent, ils formeraient un groupe de professionnels à haut risque de présenter divers problèmes de santé mentale, incluant un Trouble de stress post-traumatique (TSPT). L’objectif de la présente thèse vise à accroître les connaissances actuelles portant sur les sources de stress rencontrées pendant une mission humanitaire et des facteurs de risque et de protection liés au développement du TSPT dans un groupe de 248 TH expatriés de retour de mission depuis moins d’un an. Une première étude présente le développement d’un questionnaire auto-administré d’évaluation du stress chronique chez les travailleurs humanitaires. Une analyse factorielle a permis d’explorer la structure des 22 items de l’instrument et de supporter la présence de deux facteurs qui correspondent aux concepts de stress opérationnel et organisationnel proposés dans la littérature. Les propriétés psychométriques de l’instrument indiquent qu’il s’agit d’une mesure fidèle et valide du stress chronique rencontré par les TH dans le cadre d’une mission humanitaire. Les scores obtenus corrèlent significativement avec une mesure générale de stress, de TSPT et de dépression. En plus d’identifier les sources de stress chronique les plus fréquemment rencontrées par les TH et de quantifier le degré de stress associé à chacune de ces sources, cet instrument sera utile dans l’évaluation et la prévention de la détresse psychologique chez les TH. La seconde étude vise l’acquisition de connaissances portant sur les facteurs liés au développement du TSPT chez les travailleurs humanitaires. Une application du modèle diathèse-stress au TSPT sera utilisée dans l’échantillon de 248 travailleurs expatriés de retour de mission depuis moins d’un an. Plus spécifiquement, cette étude a pour objectif de mesurer la contribution de l’exposition aux ÉPT, du stress chronique, de la dissociation, de la personnalité de type D, du genre, et du soutien social et organisationnel sur la symptomatologie du TSPT chez les TH. Dans l’échantillon, 15,2% des travailleurs répondent aux critères diagnostiques d’un TSPT. Le modèle de régression linéaire hiérarchique proposé explique une grande portion de la variance dans la symptomatologie du TSPT (45,0%). Le stress chronique contribue à la proportion la plus élevée de variance unique dans les symptômes du TSPT, suivie de la dissociation, de l’exposition indirecte et directe aux ÉPT, finalement du soutien social et organisationnel. Un effet d’interaction significatif est observé entre le sexe et l’exposition directe aux ÉPT. Les résultats qui émaneront des deux études présentées dans cette thèse seront transmis aux organismes humanitaires afin de leur fournir des pistes de réflexion en vue d’enrichir et de mieux adapter leurs programmes de soutien à la réalité de leurs travailleurs.Humanitarian aid workers (HAW) are defined as the personnel of non-profit aid agencies that provide material and technical assistance in humanitarian relief contexts. Literature suggests that HAW are repeatedly exposed to various sources of stress, including potentially traumatic events (PTE). As a result, they are at high risk of developing mental health problems, including elevated risk for Post-Traumatic Stress Disorder (PTSD). The aim of the current thesis project is to expand our current knowledge on the different sources of stress encountered during a humanitarian mission and on the predictors of PTSD within an application of the diathesis-stress model to traumatic stress in a sample of 248 expatriate HAW back from a mission for less than a year. A first study focuses on the development and validation of a self-administered questionnaire measuring the level of chronic stress experienced by the HAW during a humanitarian mission. Exploratory factor analysis (EFA) was used to explore the underlying structure of the 22-item scale and results supported a two-factor structure, corresponding to operational and organizational stress, as proposed in the literature. The psychometrics properties of the scale were analyzed and the findings indicated the CSQ-HAW was a reliable and valid measure of chronic stress encountered by HAW while on the field. The CSQ-HAW significantly correlated with general stress and both posttraumatic stress and depression symptoms. In addition to identifying the most frequent sources of stress and quantifying the degree of stress associated with each stressor, this new instrument may serve as a meaningful tool in screening and preventing psychological distress in HAW. A second study intend to expand the current knowledge on predictors of PTSD within an application of diathesis-stress model to traumatic stress in a sample of 248 expatriate HAW back from a mission for less than a year. More specifically, this study aims to determine the prevalence rate of PTSD and examine the predictive relationship of exposure to PTE, chronic stress, dissociation, Type D personality, social and organizational support on PTSD symptomatology among expatriate HAW. In our sample, 15.8% of HAW reported levels of PTSD symptoms indicative of a PTSD diagnosis. The proposed model accounted for a large portion of the variance (45.0%) in PTSD symptomatology scores. Chronic stress accounted for the largest proportion of PTSD unique variance, followed by dissociation, indirect and indirect exposure to PTEs, and finally social and organizational support. One significant interaction effect was detected between sex and direct exposure to PTEs. Results will be shared with NGO in order to provide them with potential ways to develop specific interventions suitable for their workers

Caractérisation et identification d'antigènes érythrocytaires liant les anticorps de type HTLA

Les anticorps plasmatiques de type HTLA constituent un problème fréquemment rencontré dans les laboratoires d'immunologie érythrocytaire. Leurs caractéristiques particulières rendent d'autant plus difficile l'établissement de méthodes permettant de les éliminer, augmentant le risque de camoufler un anticorps d'importance clinique significative. Des études ont démontré que l'utilisation du récepteur du complément de type 1 sous forme soluble pourrait potentiellement neutraliser un certain nombre de ces anticorps. Certains auteurs associent également ces anticorps à la sous-classe 4 des IgG. Diverses méthodes de depletion des HTLA basées sur ces observations ont été testées dans le but d'améliorer le typage de ces échantillons. Ces travaux ont démontré que l'utilisation de peptides synthétiques de CRI représentait un bon potentiel pour y parvenir. Des analyses en biologie moléculaire ont également été réalisées dans le but d'établir le profil du CRI d'échantillons Yka-, un antigène associé aux HTLA dont la base moléculaire est inconnue

Molecular Characterization Reveals Diverse and Unknown Malaria Vectors in the Western Kenyan Highlands.

The success of mosquito-based malaria control is dependent upon susceptible bionomic traits in local malaria vectors. It is crucial to have accurate and reliable methods to determine mosquito species composition in areas subject to malaria. An unexpectedly diverse set of Anopheles species was collected in the western Kenyan highlands, including unidentified and potentially new species carrying the malaria parasite Plasmodium falciparum. This study identified 2,340 anopheline specimens using both ribosomal DNA internal transcribed spacer region 2 and mitochondrial DNA cytochrome oxidase subunit 1 loci. Seventeen distinct sequence groups were identified. Of these, only eight could be molecularly identified through comparison to published and voucher sequences. Of the unidentified species, four were found to carry P. falciparum by circumsporozoite enzyme-linked immunosorbent assay and polymerase chain reaction, the most abundant of which had infection rates comparable to a primary vector in the area, Anopheles funestus. High-quality adult specimens of these unidentified species could not be matched to museum voucher specimens or conclusively identified using multiple keys, suggesting that they may have not been previously described. These unidentified vectors were captured outdoors. Diverse and unknown species have been incriminated in malaria transmission in the western Kenya highlands using molecular identification of unusual morphological variants of field specimens. This study demonstrates the value of using molecular methods to compliment vector identifications and highlights the need for accurate characterization of mosquito species and their associated behaviors for effective malaria control

The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1-5 years in Montreal (Quebec, Canada)

Lead is neurotoxic at very low dose and there is a need to better characterize the impact of domestic sources of lead on the biological exposure of young children. A cross-sectional survey evaluated the contribution of drinking water, house dust and paint to blood lead levels (BLLs) of young children living in old boroughs of Montreal (Canada). Three hundred and six children aged 1 to 5 years and currently drinking tap water participated in the study. For each participant, residential lead was measured in kitchen tap water, floor dust, windowsill dust and house paint and a venous blood sample was analyzed. Multivariate logistic regression was used to evaluate the association between elevated BLL in the children (>/= 75th percentile) and indoor lead contamination by means of odds ratios (OR) using 95% confidence intervals (CI). There was an association between BLL >/=75th percentile (1.78 mug/dL) and water lead when the mean water concentration was >3.3 mug/L: adjusted OR=4.7 (95% CI: 2.1-10.2). Windowsill dust loading >14.1 mug/ft(2) was also associated with BLL >/=1.78 mug/dL: adjusted OR=3.2 (95% CI: 1.3-7.8). Despite relatively low BLLs, tap water and house dust lead contribute to an increase of BLLs in exposed young children

A Field Guide to Pandemic, Epidemic and Sporadic Clones of Methicillin-Resistant Staphylococcus aureus

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) have become a truly global challenge. In addition to the long-known healthcare-associated clones, novel strains have also emerged outside of the hospital settings, in the community as well as in livestock. The emergence and spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an additional cause for concern. In order to provide an overview of pandemic, epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference strains from the United States have been genotyped by DNA microarray analysis. This technique allowed the assignment of the MRSA isolates to 34 distinct lineages which can be clearly defined based on non-mobile genes. The results were in accordance with data from multilocus sequence typing. More than 100 different strains were distinguished based on affiliation to these lineages, SCCmec type and the presence or absence of PVL. These strains are described here mainly with regard to clinically relevant antimicrobial resistance- and virulence-associated markers, but also in relation to epidemiology and geographic distribution. The findings of the study show a high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements. The data also indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements

A Field Guide to Pandemic, Epidemic and Sporadic Clones of Methicillin-Resistant Staphylococcus aureus

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) have become a truly global challenge. In addition to the long-known healthcare-associated clones, novel strains have also emerged outside of the hospital settings, in the community as well as in livestock. The emergence and spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an additional cause for concern. In order to provide an overview of pandemic, epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference strains from the United States have been genotyped by DNA microarray analysis. This technique allowed the assignment of the MRSA isolates to 34 distinct lineages which can be clearly defined based on non-mobile genes. The results were in accordance with data from multilocus sequence typing. More than 100 different strains were distinguished based on affiliation to these lineages, SCCmec type and the presence or absence of PVL. These strains are described here mainly with regard to clinically relevant antimicrobial resistance- and virulence-associated markers, but also in relation to epidemiology and geographic distribution. The findings of the study show a high level of biodiversity among MRSA, especially among strains harbouring SCCmec IV and V elements. The data also indicate a high rate of genetic recombination in MRSA involving SCC elements, bacteriophages or other mobile genetic elements and large-scale chromosomal replacements

DMTs and Covid-19 severity in MS: a pooled analysis from Italy and France

We evaluated the effect of DMTs on Covid-19 severity in patients with MS, with a pooled-analysis of two large cohorts from Italy and France. The association of baseline characteristics and DMTs with Covid-19 severity was assessed by multivariate ordinal-logistic models and pooled by a fixed-effect meta-analysis. 1066 patients with MS from Italy and 721 from France were included. In the multivariate model, anti-CD20 therapies were significantly associated (OR = 2.05, 95%CI = 1.39–3.02, p < 0.001) with Covid-19 severity, whereas interferon indicated a decreased risk (OR = 0.42, 95%CI = 0.18–0.99, p = 0.047). This pooled-analysis confirms an increased risk of severe Covid-19 in patients on anti-CD20 therapies and supports the protective role of interferon

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia