Éditeur(s) : Inter-Research
Résumé : Experimental infections of Penaeus (Litopenaeus) stylirostris were performed with a Vibrio penaeicida strain (AM101) isolated in New Caledonia from Syndrome 93 diseased shrimp. Cumulative mortalities resulting from intramuscular injection or immersion of shrimp in bacterial suspensions demonstrated high virulence for this bacterial strain and suggested that V. penaeicida could be the etiological agent of Syndrome 93. The median lethal dose (LD50) for AM101 was 1.3 x 104 CFU (colony forming units) ml-1 by immersion and less than 5 CFU shrimp-1 by intramuscular challenge, with mortality outbreaks at 48 and 22 h after challenge, respectively. A polymerase chain reaction (PCR) detection assay using a primer set designed from the 16S ribosomal RNA gene of V. penaeicida was developed. It gave an expected amplicon of approximately 310 bp in ethidium bromide-stained agarose gels. The specificity of these primers was assessed with different Vibrio species. Furthermore, DNA extracted by the ChelexTM method could be used to detect fewer than 20 cultured Vibrio cells in seawater or shrimp hemolymph by this assay. It appears to be a reliable screening method for detecting V. penaeicida in shrimp and from the aquatic environment.
Diseases of aquatic organisms (0177-5103) (Inter-Research), 2000-03 , Vol. 49 , N. 2 , P. 109-115

Droits : Inter-Research 2000
http://archimer.ifremer.fr/doc/2000/publication-4436.pdf
DOI:10.3354/dao040109
http://archimer.ifremer.fr/doc/00000/4436/

Résumé : En Guyane comme dans l'ensemble de la région amazonienne, le risque de maladie de Chagas pour l'homme a longtemps été sous estimé du fait de l'absence de vecteur domestique et de l'existence d'un réservoir animal exclusivement sauvage. Le travail présenté répond aux besoins de compléter et d'actualiser les connaissances épidémiologiques disponibles sur la maladie de Chagas dans ce département , en précisant les modalités de circulation de Trypanosoma cruzi et les facteurs impliqués dans le cycle à l'origine des cas humains. Les données cumilées entre 2001 et 2023 représentent 971 spécimens de triatomes. Nous avons choisi de différencier les triatomes provenant des zones non habitées (forêts primaire ou secondaire) de ceux provenant de zones habitées, collectées dans les maisons à la faveur d'intrusion. Une espère, Panstrongylus geniculatus, s'est distinguée par son abondance (61,1%) et son omniprésence dans les différents types de milieux explorés. Au total, neuf espèces ont été retrouvées. En zone non habitée, avec une prédominance de P. geniculatus, P. lignarius, Rhodnius pictipes et R. robustus. L'infection des triatomes par T. cruzi a été étudiée, avec une mise en évidence d'un taux d'infection plus élevé chez les triatomes collectés à l'intérieur des habitations (53.9%) que chez ceux provenant des zones non habitées (46%). L'étude sur les mammifères sauvages a montré des taux d'infection élevés pour T. cruzi chez deux espèces : didelphis marsupialis (62.5%) et Philander opossum (35%). Cette étude a été complétée par l'analyse de la variabilité génétique de T. cruzi identifié par des techniques de génotypage réalisées sur du matériel obtenu à partir de triatomes, de mammifères sauvages et domestiques et des hommes. En zone non habitée trois groupes, TcI, TcII-TcV-TcVI et TcIII-TcIV, ont été caractérisés, avec une prédominance de TcI. Parmi les acteurs du cycle parasite, les chiens et P. geniculatus hébergent le groupe TcIII-TcIV à la différence du genre Rhodnius et des marsupiaux qui hébergent le groupe TcI. Nos résultats ont permis d'émettre un certain nombre d'hypothèses sur la circulation des génotypes de T. cruzi en Guyane
In French Guiana, as in the whole of Amazon region, the risk of Chagas disease to humans has long been underestimated due to the presence of non-domiciled triatomines and wild animal reservoir. Overall, this thesis aims at reactualizing and improving epidemiological knowledge about Chagas disease in French Guiana, by specific modalities of circulation of Trypanosoma cruzi and the factorsinvolved in the transmission cycle of the origin of human cases. Accumulated data, between 2001 and 2013, represent 971 triatomine specimens collected. We chose to differentiate triatomine collected in uninhabited areas (primary or secondary forests) and those frominhabited areas, collected in homes by intrusion. One species, Panstrongylus geniculatus, was distinguished by its abundance (61.1%) and its presence in different types of habitats investigated. A total of nine species were found in uninhabited area, with the predominance of four species: P. geniculatus, P. lignarius, Rhodnius pictipes and Eratyrus mucronatus. In inhabited area, five species of triatomine were collected, with the predominance of P. geniculatus, R. pictipes and R. robustus. The triatomine infection rate with T. cruzi has been studied, with a highlighting of higher rate of infection in triatomine collected inside houses (53.9%) than those from uninhabited area (46%). The study on wild mammals showed high T. cruzi infection rates for two species: Didelphis marsupialis (62.5%) and Philander opossum (35%).This study was completed by the analysis of the genetic variability of T. cruzi identified by genotyping techniques performed on material obtained from triatomine, wild and domestic mammals and humans. In uninhabited area, three groups$ TcI, TcII-TcV-TcVI and TcIII-TcIV have been characterized, with a predominance of TcIII-TcIV group. In inhabited area, only two groups were characterized (TcI andTcIII-TcIV), with a predominance of TcI. Among the actor’s transmission cycle of parasite, dogs and P. geniculatus were characterized by TcIII-TcIV group. Contrary to Rhodnius genus and marsupials were characterized by the TcI group. Our results have allowed issuing a number of assumptions about the circulation of T. cruzi genotypes in French Guiana

http://www.theses.fr/2013AGUY0734/document

Éditeur(s) : Inter-Research
Résumé : Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) were purified from diseased freshwater prawns M rosenbergii and used to infect healthy post-larvae (PL) by an immersion method. Three groups of prawns were challenged with various combined doses of MrNV and XSV. Signs of white-tail disease (WTD) were observed in Groups 1 and 2, which had been challenged with combinations containing relatively high proportions of MrNV and low proportions of XSV. By contrast there was little sign of WTD in Group 3, which had been challenged with a higher proportion of XSV than MrNV. A 2-step Taqman real-time RT-PCR was developed and applied to quantify viral copy numbers in each challenged PL. Results showed that genomic copies of both viruses were much higher in Groups 1 and 2 than they were in Group 3, indicating that MrNV plays a key role in WTD of M rosenbergii. The linear correlation between MrNV and XSV genome copies in infected prawns demonstrated that XSV is a satellite virus, dependent on MrNV, but its role in pathogenicity of WTD remains unclear.
Diseases of aquatic organisms (0177-5103) (Inter-Research), 2006-07 , Vol. 71 , N. 1 , P. 11-17

Droits : Inter-Research 2006
http://archimer.ifremer.fr/doc/2006/publication-3568.pdf
DOI:10.3354/dao071011
http://archimer.ifremer.fr/doc/00000/3568/

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
UNLABELLED: During visceral leishmaniasis, the control of hepatic parasite burden is mainly due to granuloma assembly in a microenvironment consisting of both Th1 and Th2 components. Using enzyme-linked immunosorbent assay (ELISA) dosages, quantitative PCR (qPCR), immunohistochemistry, and flow cytometry, we studied the role of interleukin-33 (IL-33), a recently described cytokine signaling through the ST2 receptor, during visceral leishmaniasis. We showed that a higher level of IL-33 was detected in the serum of patients with visceral leishmaniasis than in that from healthy donors and demonstrated the presence of IL-33(+) cells in a liver biopsy specimen from a patient. Similarly, in BALB/c mice experimentally infected with L. donovani, a higher level of IL-33 was detected in the serum, as well as the presence of IL-33(+) cells and ST2(+) cells in the mouse liver. In ST2(-/-) BALB/c mice, better control of the hepatic parasite burden and reduced hepatomegaly were observed. This was associated with strong induction of Th1 cytokines (gamma interferon [IFN-γ] and IL-12) compared to the level in wild-type (WT) mice and better recruitment of myeloid cells associated with strongly induced chemokines (CCL2 and CXCL2) and receptors (CCR2 and CXCR2). Conversely, BALB/c mice treated twice weekly with recombinant IL-33 showed a dramatically reduced induction of Th1 cytokines and delayed inhibition of monocyte and neutrophil recruitment in the liver, which was associated with reduced KC/CXCL1 and CXCR2 expression. Taken together, our results suggest that IL-33 could be a new deleterious regulator of the hepatic immune response against Leishmania donovani, via the repression of the Th1 response and myeloid cell recruitment. IMPORTANCE: Visceral leishmaniasis is a life-threatening systemic disease due to the Leishmania protozoa L. infantum and L. donovani and is ranked by the World Health Organization as the second most important protozoan parasitic disease after malaria for its grave morbidity, high mortality, and global distribution. Leishmania parasites subvert the host's immune response to propagate to target organs, including the spleen, the bone marrow, and the liver. Control of hepatic parasite burdens depends on a delicate and poorly understood Th1/Th2 immune balance. To better understand this complex immune response, new cytokines are interesting targets for research studies. IL-33 is a newly described cytokine usually associated with Th2 response and involved in different diseases, including infectious diseases and hepatitis. Our results suggest that IL-33 could be a new factor of susceptibility and a potential prognostic marker during visceral leishmaniasis.
ISSN: 2150-7511

inserm-00871493
http://www.hal.inserm.fr/inserm-00871493
http://www.hal.inserm.fr/inserm-00871493/document
http://www.hal.inserm.fr/inserm-00871493/file/mBio.00383-13.pdf
DOI : 10.1128/mBio.00383-13

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Background: Influenza is an important cause of serious illness and death, particularly in elderly and high-risk groups. Objectives Aim of this study was to identify factors associated with poor outcomes among adults hospitalized in France for laboratory-confirmed seasonal influenza. Study design Patients hospitalized for influenza were identified in a prospective, multicenter study carried out in French hospitals during three consecutive influenza seasons (2012–2015). Influenza virus infection was confirmed by reverse transcription polymerase chain reaction. Sociodemographic and clinical variables were compared according to the virus type and subtype. Risk factors for complications, intensive care unit (ICU) admission and death were analyzed by backward stepwise logistic regression. Results The study population consisted of 566 patients, of whom 56% were older than 65 years and 82% had underlying chronic illnesses. Type A influenza viruses infected 422 patients (75%), including subtype H3N2 in 239 patients (57%). The prior vaccine coverage rate was 38%. Complications occurred in 255 patients (45%), consisting mainly of pneumonia (n = 143, 30%) and respiratory failure (n = 116, 20%). Eighty-three patients (15%) were admitted to an ICU, and the in-hospital mortality rate was 4% (n = 21). Sixty-six patients (12%) received oseltamivir. Age over 65 years was the only identified risk factor for complications. Risk factors for ICU admission were an absence of vaccination, no oseltamivir administration before admission, pre-existing chronic respiratory disease, and current smoking. Age over 65 years and ICU admission were risk factors for death. Conclusions Older individuals and patients with underlying conditions are most at risk of influenza complications. Vaccination and early oseltamivir administration, both of which are recommended for these patients, appear to reduce ICU admissions
ISSN: 1386-6532

hal-01302409
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01302409
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01302409/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01302409/file/Factors%20associated%20with%20poor%20outcomes.pdf
DOI : 10.1016/j.jcv.2016.04.005

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
ABSTRACT: In the past decade, there has been an increasing number of studies on co-infections between worms and malaria. However, this increased interest has yielded results that have been at times conflicting and made it difficult to clearly grasp the outcome of this interaction. Despite the heterogeneity of study designs, reviewing the growing body of research may be synthesized into some broad trends: Ascaris emerges mostly as protective for malaria and its severe manifestations, whereas hookworm seems to increase malaria incidence. As efforts are made to de-worm populations in malaria endemic areas, there is still no clear picture of the impact these programmes have in terms of quantitative and qualitative changes in malaria.
ISSN: 1475-2875

inserm-00632065
http://www.hal.inserm.fr/inserm-00632065
http://www.hal.inserm.fr/inserm-00632065/document
http://www.hal.inserm.fr/inserm-00632065/file/1475-2875-10-259.pdf
DOI : 10.1186/1475-2875-10-259

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
BACKGROUND: The timing of cardiac surgery after stroke in infective endocarditis (IE) remains controversial. We examined the relationship between the timing of surgery after stroke and the incidence of in-hospital and 1-year mortalities. METHODS: Data were obtained from the International Collaboration on Endocarditis-Prospective Cohort Study of 4794 patients with definite IE who were admitted to 64 centers from June 2000 through December 2006. Multivariate logistic regression and Cox regression analyses were performed to estimate the impact of early surgery on hospital and 1-year mortality after adjustments for other significant covariates. RESULTS: Of the 857 patients with IE complicated by ischemic stroke syndromes, 198 who underwent valve replacement surgery poststroke were available for analysis. Overall, 58 (29.3%) patients underwent early surgical treatment vs 140 (70.7%) patients who underwent late surgical treatment. After adjustment for other risk factors, early surgery was not significantly associated with increased in-hospital mortality rates (odds ratio, 2.308; 95% confidence interval [CI], .942-5.652). Overall, probability of death after 1-year follow-up did not differ between 2 treatment groups (27.1% in early surgery and 19.2% in late surgery group, P = .328; adjusted hazard ratio, 1.138; 95% CI, .802-1.650). CONCLUSIONS: There is no apparent survival benefit in delaying surgery when indicated in IE patients after ischemic stroke. Further observational analyses that include detailed pre- and postoperative clinical neurologic findings and advanced imaging data (eg, ischemic stroke size), may allow for more refined recommendations on the optimal timing of valvular surgery in patients with IE and recent stroke syndromes.
ISSN: 1058-4838

hal-00875143
https://hal.archives-ouvertes.fr/hal-00875143
DOI : 10.1093/cid/cis878
PUBMED : 23074311

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Alveolar proteinosis (AP) is a rare disease characterized by alveolar accumulation of surfactant components, which impairs gas exchange. AP is classified into three groups: auto-immune AP defined by the presence of plasma autoantibodies anti-GM-CSF, the most frequent form (90 % of all AP); secondary AP, mainly occurring as a consequence of haematological diseases, or following on from toxic inhalation or infections, and genetic AP, which affects almost exclusively children. AP diagnosis is suspected where chest CT-scan demonstrates interstitial lung disease with a crazy paving aspect; and confirmed by bronchoalveolar lavage, which has a milky appearance and contains periodic acid Schiff positive proteinaceous alveolar deposits. The use of surgical lung biopsy to confirm AP is less frequent nowadays. In this context, positive antibodies against GM-CSF indicates an auto-immune etiology of the AP. Concerning management, whole lung lavage is the gold standard therapy. In refractory AP, new treatments are available such as subcutaneous or inhaled GM-CSF supplementation, or rituximab infusions. The clinical course is unpredictable. Spontaneous improvement or even cure can occur, and the 5-year actuarial survival is 95 %. The most frequent complications are infectious etiology.
La protéinose alvéolaire pulmonaire (PAP) est une maladie rare caractérisée par l’accumulation alvéolaire de composants du surfactant qui gêne les échanges gazeux. Les PAP sont séparées en trois groupes : les PAP auto-immunes caractérisées par la présence d’anticorps sériques anti-GM-CSF qui sont les plus fréquentes ; les PAP secondaires à une maladie sous-jacente, le plus souvent hématologique, mais aussi à l’inhalation de toxiques et à des infections ; enfin, les PAP d’origine génétique. Le diagnostic de PAP est évoqué sur le scanner thoracique avec une pneumopathie infiltrante diffuse ayant un aspect classique de crazy paving, puis confirmé par l’aspect laiteux du lavage bronchoalvéolaire, et la présence de matériel lipoprotéinacé PAS positif. La confirmation du diagnostic de PAP par biopsie pulmonaire chirurgicale est désormais rarement nécessaire. La positivité des anticorps sériques anti-GM-CSF signe le caractère auto-immun de la maladie. Le traitement de référence des PAP auto-immunes est le « grand lavage pulmonaire thérapeutique ». En cas de maladie réfractaire, d’autres traitements sont disponibles, tels que le GM-CSF en injection sous-cutanée ou en aérosol et le rituximab. L’évolution de la maladie est imprévisible. Une évolution spontanément favorable ou même une guérison spontanée peuvent survenir et la survie actuarielle à 5 ans est de 95 %. Les principales complications sont infectieuses.
ISSN: 0761-8425

hal-01085907
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01085907
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01085907/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01085907/file/Prot%C3%A9inose%20alv%C3%A9olaire%20pulmonaire_accepted.pdf
DOI : 10.1016/j.rmr.2014.08.009

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
BACKGROUND: A prospective study of infectious encephalitis was conducted in France in 2007. In total, 253 patients were enrolled with a proven etiological diagnosis for 52%. The cohort of surviving patients with encephalitis was assessed for sequelae and impairment 3 years after enrollment. METHODS: Patients, their family, and general practitioners (GPs) were interviewed by phone to document persisting symptoms, return to work, and past and current leisure activities, with standardized questionnaires. The IQCODE (Informant Questionnaire on Cognitive Decline in the Elderly) was completed with relatives. The global outcome was determined in all patients with the Glasgow outcome scale. RESULTS: In 2010, 20 patients (10%) were unavailable for follow-up, 2 (1%) were excluded, and 18 (9%) had died since hospital discharge. Data were available for 167 survivors and 9 patients whose death was related to the encephalitis. The outcome was favorable in 108 of 176 patients (61%) (71 with complete resolution), 31 (18%) were mildly impaired, 25 (14%) were severely impaired, and 3 (1%) were in a vegetative state. The most frequent symptoms were difficulty concentrating (42%), behavioral disorders (27%), speech disorders (20%), and memory loss (19%). Fifteen of 63 patients (24%) previously employed were still unable to resume work. Long-term outcome was significantly associated with comorbid conditions, age, level of education, and the causative agent of encephalitis. CONCLUSIONS: Most patients with encephalitis experienced a favorable outcome 3 years after hospital discharge. However, minor to severe disability persists in a high number of cases with consequences for everyday life. Physical and mental impairment should be evaluated in all patients with encephalitis, and neuropsychological rehabilitation implemented whenever needed.
ISSN: 1058-4838

hal-00875190
https://hal.archives-ouvertes.fr/hal-00875190
DOI : 10.1093/cid/cis226
PUBMED : 22460967

Éditeur(s) : Colloque IMBC - International Marine Biotechnology Conference
Résumé : Since 1997, a new pathology seasonally occurs in new caledonian shrimp farms during the warm season. Diseased Litopenaeus stylirostris shrimp suffer from a systemic vibriosis which was attributed to highly pathogenic Vibrio nigripulchritudo. At the present time, only two farms among 17 are affected by the so called "summer syndrome". In such a context it appears urgent to develop reliable diagnostic tools to detect V. nigripulchritudo strains and to differentiate highly virulent strains from non virulent ones in order to understand the mechanisms of infection and overcome disease spreading. Multilocus Sequencing Typing (MLST) analysis on 24 bacterial strains isolated in geographically distinct shrimp farms highlighted the existence of a cluster A containing only strains displaying moderate to high virulence. Since experimental infection procedure for virulence status determination is material intensive and time consuming, and MLST method not accurate enough to inform on the virulence status of strains, it appeared of great interest to develop other diagnostic tools. Two phylogenetically closed strains, one highly virulent SFn1 and the other non-virulent SFn118 were selected in order to characterize genes specific of the virulent strain by Substractive Suppression Hybridization (SSH). Firstly, a total of 622 DNA fragments specific of SFn1 were sequenced, characterized and further used as probes in a DNA macroarray. Testing 24 strains, hybridization profiles were found to be strongly correlated with both MLST genotypes and bacterial virulence status. A total of 96 representative probes were secondly selected to validate macroarray results on 34 more additionnal strains, allowing identification of genetic markers of virulence. Most of DNA fragments specific of highly virulent strains associated to summer syndrome were found to be bore by a plasmid successfully isolated in the laboratory. In next future, these results would permit the development of relevant diagnostic tools useful for accurate epidemiological survey of the summer syndrome.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2007/acte-3398.pdf
http://archimer.ifremer.fr/doc/00000/3398/

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
BACKGROUND: Histoplasmosis is an endemic fungal infection in French Guiana. It is the most common AIDS-defining illness and the leading cause of AIDS-related deaths. Diagnosis is difficult, but in the past 2 decades, it has improved in this French overseas territory which offers an interesting model of Amazonian pathogen ecology. The objectives of the present study were to describe the temporal trends of incidence and mortality indicators for HIV-associated histoplasmosis in French Guiana. METHODS: A retrospective study was conducted to describe early mortality rates observed in persons diagnosed with incident cases of HIV-associated Histoplasma capsulatum var. capsulatum histoplasmosis admitted in one of the three main hospitals in French Guiana between 1992 and 2011. Early mortality was defined by death occurring within 30 days after antifungal treatment initiation. Data were collected on standardized case report forms and analysed using standard statistical methods. RESULTS: There were 124 deaths (45.3%) and 46 early deaths (16.8%) among 274 patients. Three time periods of particular interest were identified: 1992-1997, 1998-2004 and 2005-2011. The two main temporal trends were: the proportion of early deaths among annual incident histoplasmosis cases significantly declined four fold (χ2, p<0.0001) and the number of annual incident histoplasmosis cases increased three fold between 1992-1997 and 1998-2004, and subsequently stabilized. CONCLUSION: From an occasional exotic diagnosis, AIDS-related histoplasmosis became the top AIDS-defining event in French Guiana. This was accompanied by a spectacular decrease of early mortality related to histoplasmosis, consistent with North American reference center mortality rates. The present example testifies that rapid progress could be at reach if awareness increases and leads to clinical and laboratory capacity building in order to diagnose and treat this curable disease.
ISSN: 1935-2727

inserm-01065109
http://www.hal.inserm.fr/inserm-01065109
http://www.hal.inserm.fr/inserm-01065109/document
http://www.hal.inserm.fr/inserm-01065109/file/PLOS_Neglected_Tropical_Dis_2014.pdf
http://www.hal.inserm.fr/inserm-01065109/file/2014_Adenis_-_HIV-associated_histoplasmosis_early_mor.pdf

Éditeur(s) : Gauthier-villars
Résumé : Until recently, the study of the pathology of oysters concerned some bacterial and a large number of parsitic diseases. Among the latter, diseases caused by fungi such as Labyrinthomyxa marina or by sporozoa such as Minchinia nelsoni in the American oyster have had very important econimic repercussions in the affected areas. The causes of some severe epizooties, such as the "Malpecue Bay disease" in Canada, have never been determined; in other cases, including the mass mortality of the Portuguese oyster in Fance, several years of investigations have been required before the first results of an etiologic nature were obtained. The use of electron microscopy has permitted great strides in the pathology of oysters. Thus, virus diseases have been found to be associated with the diseases of the Portuguse oyster, with gill disease and with the mass mortality of 1970. New and important data have also been obtained with regard to the structure and development of Marteilia refringens a parasite of the flat oyster which has been recognized as belonging to the haplosporidan species. Recently, Mycoplasma-like and Rickettsia-like organisms have been detected in several oyster species and oyster viruses have been isolated on cell cultures. Such results confirm the evolution of research in this field.
Les résultats acquis en matière de pathologie des huîtres concernaient jusqu'à une date récente quelques maladies bactériennes et surtout de nombreuses parasitoses. Pour certaines épizooties graves, comme la maladie de l'huître américaine de Malpèque au Canada, les causes n'ont jamais été déterminées et pour d'autres, comme la mortalité massive de l'huître portugaise en France, les premiers résultats d'ordre étiologique n'ont été obtenus que tardivement avec la mise en évidence d'une infection virale. L'étude ultra-structurale de Marteilia refringens, parasite de l'huître plate, la mise en évidence d'une virose associées à la maladie des branchies de l'huître portugaise, puis la découverte récente de nouveaux germes pathogènes tels que mycoplasmes et rickettsies et l'isolement de virus sur cultures cellulaires chez plusieurs espèces d'huîtres devaient confirmer l'évolution des recherches dans ce domaine.
Oceanologica Acta (0399-1784) (Gauthier-villars), 1978 , Vol. 1 , N. 2 , P. 255-262

Droits : 1978 Elsevier
http://archimer.ifremer.fr/doc/00015/12631/9520.pdf
http://archimer.ifremer.fr/doc/00015/12631/

Éditeur(s) : HAL CCSD Taylor & Francis (Routledge): STM, Behavioural Science and Public Health Titles
Résumé : International audience
The aim of this study was to determine factors associated with complete satisfaction with the care provided (satisfaction with physicians and satisfaction with services and organization) among HIV-infected patients followed up in the French ANRS CO8 APROCO-COPILOTE cohort. Analyses focused on cross-sectional data collected during the ninth year of cohort follow-up. Satisfaction with care, sociodemographic characteristics, and behavioral data were collected using self-administered questionnaires, while clinical data were derived from medical records. Complete satisfaction with care was defined as being 100% satisfied. Two logistic regression models were used to identify predictors of (1) complete satisfaction with physicians (n=404) and (2) complete satisfaction with services and organization (n=396). Sixteen percent of patients were completely satisfied with physicians, while 15.9% were completely satisfied with services and organization. Being older and reporting fewer discomforting antiretroviral therapy (ART) side effects were factors independently associated with complete satisfaction with both physicians and services and organization. Strong support from friends and absence of hepatitis C (HCV) co-infection were independently associated with complete satisfaction with physicians, while strong support from one's family and comfortable housing conditions were independently associated with complete satisfaction with services and organization. Even after nine years of follow-up, social vulnerabilities still strongly influence HIV-infected patients' interactions with the health care system. Day-to-day experience with the disease, including perceived treatment side effects, appears to play a key role in the quality of these interactions. More attention should be given to patient satisfaction, especially for socially vulnerable patients, in order to avoid potentially detrimental consequences such as poor adherence to ART.
AIDS Care

hal-00875619
https://hal.archives-ouvertes.fr/hal-00875619
DOI : 10.1080/09540121.2011.613909
PUBMED : 21999644

Éditeur(s) : HAL CCSD
Résumé : International audience
Structure and evolution of networks have been areas of growing interest in recent years, especially with the emergence of Social Network Analysis (SNA) and its application in numerous fields. Researches on diffusion are focusing on network modeling for studying spreading phenomena. While the impact of network properties on spreading is now widely studied, involvement of network dynamicity is very little known. In this paper, we address the epidemiology context and study the consequences of network evolutions on spread of diseases. Experiments are conducted by comparing incidence curves obtained by evolution strategies applied on two generated and two real networks. Results are then analyzed by investigating network properties and discussed in order to explain how network evolution influences the spread. We present the MIDEN framework, an approach to measure impact of basic changes in network structure, and DynSpread, a 2D simulation tool designed to replay infections scenarios on evolving networks.
Database and Expert Systems Applications - 22nd International Conference, DEXA 2011, Toulouse, France, August 29 - September 2, 2011, Proceedings, Part II
Toulouse, France

hal-00614925
https://hal.archives-ouvertes.fr/hal-00614925
DOI : 10.1007/978-3-642-23091-2_49

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
Coronaviruses (CoVs) have shown neuroinvasive properties in human and animal secondary to replication in peripheral organ but the mechanism of neuroinvasion is unknown. The major aim of our work was to evaluate the ability of CoVs to enter the central nervous system (CNS) through the blood brain barrier (BBB). Using the high hepatotropic mouse hepatitis virus (MHV) type 3, its attenuated variant 51.6-MHV3, showing low tropism for endothelial cells, and the low hepatotropic MHV-A59 strains from murine coronavirus group, we investigated the viral-induced dysfunctions of BBB in vivo and in brain microvascular endothelial cells (BMECs) in vitro. We report here a MHV strain-specific ability to cross the BBB during acute infection according to their virulence for liver. Brain invasion was only observed in MHV3-infected mice and correlated with enhanced BBB permeability associated with decreased expression of ZO-1, VE-cadherin and occludin but not claudin-5 in the brain or in cultured BMECs. BBB breakdown in MHV3 infection was not related to production of barrier-dysregulating inflammatory cytokines or chemokines by infected BMECs but rather to a downregulation of barrier protective IFN-β production. Our findings highlight the importance of IFN-β production by infected BMECs in preserving BBB function and preventing access of blood-borne infectious viruses to the brain. IMPORTANCE: Coronaviruses (CoVs) infect several mammals including humans and are associated with respiratory, gastrointestinal and/or neurological diseases. Some evidences suggest that human respiratory CoVs may show neuroinvasive properties. Indeed, the SARS-CoV, causing severe acute respiratory syndrome, and the CoVs OC43 and 229E were found in the brains of SARS and multiple sclerosis patients respectively. These finding suggest that hematogenous spread CoVs may gain access to CNS at the BBB level. Herein we report for the first time that CoVs exhibit ability to cross the BBB according to strain virulence. BBB invasion by CoVs correlates with viral-induced disruption of tight junctions on BMECs, leading to BBB dysfunction and enhanced permeability. We provide evidence that production of IFN-β by BMECs during CoV infection may prevent BBB breakdown and brain viral invasion
ISSN: 0022-538X

hal-01187308
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187308
DOI : 10.1128/JVI.01501-15
PUBMED : 26202229

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
UNLABELLED: ABSTRACT: BACKGROUND: Malaria is a major health issue in French Guiana. Amerindian communities remain the most affected. A previous study in Camopi highlighted the predominant role of environmental factors in the occurrence of malaria. However, all parameters involved in the transmission were not clearly identified. A new survey was conducted in order to clarify the risk factors for the presence of malaria cases in Camopi. METHODS: An open cohort of children under seven years of age was set up on the basis of biologically confirmed malaria cases for the period 2001-2009. Epidemiological and observational environmental data were collected using two structured questionnaires. Data were analysed with a multiple failures multivariate Cox model. The influence of climate and the river level on malaria incidence was evaluated by time-series analysis. Relationships between Anopheles darlingi human biting rates and malaria incidence rates were estimated using Spearman's rank correlation. RESULTS: The global annual incidence over the nine-year period was 238 per 1,000 for Plasmodium falciparum, 514 per 1,000 for Plasmodium visa and 21 per 1,000 for mixed infections. The multivariate survival analysis associated higher malaria incidence with living on the Camopi riverside vs. the Oyapock riverside, far from the centre of the Camopi hamlet, in a home with numerous occupants and going to sleep late. On the contrary, living in a house cleared of all vegetation within 50 m and at high distance of the forest were associated with a lower risk. Meteorological and hydrological characteristics appeared to be correlated with malaria incidence with different lags. Anopheles darlingi human biting rate was also positively correlated to incident malaria in children one month later. CONCLUSIONS: Malaria incidence in children remains high in young children despite the appearance of immunity in children around three years of age. The closeness environment but also the meteorological parameters play an important role in malaria transmission among children under seven years of age in Camopi.
ISSN: 1475-2875

inserm-00633771
http://www.hal.inserm.fr/inserm-00633771
http://www.hal.inserm.fr/inserm-00633771/document
http://www.hal.inserm.fr/inserm-00633771/file/1475-2875-10-246.pdf
DOI : 10.1186/1475-2875-10-246

Résumé : Cette thèse concerne la modélisation des dynamiques de maladies foliaires de cultures pérennes tropicales à différentes échelles spatiales. Cette approche de modélisation est appliquée à la cercosporiose noire du bananier. Il s’agit d’explorer et de déterminer les paramètres environnementaux et de résistance de l’hôte ayant une influence significative sur la dynamique spatiotemporelle de la maladie et d’apporter des éléments associés au contrôle de la cercosporiose noire.Deux modèles ont été développés dans le cadre de cette thèse. La dynamique épidémiologique au niveau de la plante est décrite par un modèle mécaniste décomposé en un modèle de croissance de la plante et un module épidémiologique décrivant le cycle épidémique du pathogène. L’architecture du bananier est prise en compte par le biais de compartiments foliaires positionnés dans l’espace. Le modèle a été validé par un jeu de données indépendant. Les expérimentations numériques et l’analyse de sensibilité du modèle réalisées par les méthodes de Morris et de e-FAST ont permis de mieux comprendre le fonctionnement épidémique de cette maladie et d’identifier les paramètres influant le plus la dynamique épidémique en particulier la vitesse d’extension des lésions, la durée d’incubation et l’efficacité d’infection .L’approche bayésienne a permis de prendre en compte l’information a priori disponible pour ces trois paramètres sur lesquels a porté l’inférence statistique. L’analyse de sensibilité du modèle a également permis d’identifier l’influence de deux paramètres liés à la croissance de la plante : le nombre de feuilles sur une plante et le rythme d’émission foliaire Un modèle de dynamique spatio-temporelle de la cercosporiose noire a été développé à l’échelle d’un territoire à partir d’enquêtes effectuées enMartinique pendant la période d’invasion de cette maladie de septembre 2010 à mai 2012. Les données récoltées étant censurées, l’inférence des paramètres du modèle a été réalisée dans un cadre bayésien en utilisant un algorithme d’augmentation de données. Le modèle et l’inférence développés permettent de reconstruire la dynamique spatio-temporelle de l’invasion et de prédire la fin d’invasion sur le territoire.Les deux modèles de dynamiques spatio-temporelles développés à deux échelles spatiales différentes ont permis d’acquérir des informations importantes pour construire des outils de conception de méthode de contrôle de la cercosporiose noire des bananiers.
This thesis concerns the modeling of the dynamics of foliar diseases of tropical tree crops at different spatial scales. This modeling approach is applied to black Sigatoka of banana. It is to explore and determine the environmental parameters and host resistance has a significant influence on the spatiotemporal dynamics of the disease and to provide elements associated with the control of Sigatoka noire.Deux models were developed as part of this thesis. The epidemiological dynamics at the plant is described by a mechanistic model decomposed into a growth model of the plant and an epidemiological unit describing the pathogen epidemic cycle. The architecture of the banana is taken into account through foliar compartments positioned in space. The model was validated by an independent data set. Numerical experiments and model sensitivity analysis performed by the methods of Morris and e-FAST enabled to better understand the functioning of this epidemic disease and identify the parameters affecting the most dynamic epidemic especially speed extension of the lesions, the incubation period and efficiency of Bayesian .L'approche infection allowed to take into account prior information available for these three parameters that were the statistical inference. The model sensitivity analysis also identified the influence of two parameters related to plant growth: the number of leaves on a plant and rate of leaf emission A dynamic model of space-time Black Sigatoka has been developed at the scale of a territory from surveys enMartinique during the period of invasion of the disease from September 2010 to May 2012. The data collected being censored, inference of model parameters has was performed in a Bayesian framework, using a data augmentation algorithm. The model developed and inference possible to reconstruct the spatiotemporal dynamics of the invasion and predict the end of the invasion territoire.Les two spatio-temporal dynamics models developed at two different spatial scales has been gained important information for build tools design method of control of black Sigatoka of banana.

http://www.theses.fr/2015AGUY0835/document

Éditeur(s) : HAL CCSD Hindawi Publishing Corporation
Résumé : International audience
HLA-G is a nonclassical major histocompatibility complex molecule first described at the maternal-fetal interface, on extravillous cytotrophoblasts. Its expression is restricted to some tissues in normal conditions but increases strongly in pathological conditions. The expression of this molecule has been studied in detail in cancers and is now also beginning to be described in infectious diseases. The relevance of studies on HLA-G expression lies in the well known inhibitory effect of this molecule on all cell types involved in innate and adaptive immunity, favoring escape from immune control. In this review, we summarize the features of HLA-G expression by type of infections (i.e, bacterial, viral, or parasitic) detailing the state of knowledge for each pathogenic agent. The polymorphism, the interference of viral proteins with HLA-G intracellular trafficking, and various cytokines have been described to modulate HLA-G expression during infections. We also discuss the cellular source of HLA-G, according to the type of infection and the potential role of HLA-G. New therapeutic approaches based on synthetic HLA-G-derived proteins or antibodies are emerging in mouse models of cancer or transplantation, and these new therapeutic tools may eventually prove useful for the treatment of infectious diseases.
ISSN: 2314-8861

hal-01063925
https://hal.archives-ouvertes.fr/hal-01063925
https://hal.archives-ouvertes.fr/hal-01063925/document
https://hal.archives-ouvertes.fr/hal-01063925/file/Immunomodulatory%20Properties%20of%20HLA-G.pdf
DOI : 10.1155/2014/298569

Éditeur(s) : HAL CCSD
Résumé : Molds are common contaminants in indoor environments. Health effects associated with these microscopic fungi are multiple, including irritations, allergic reactions, infections and toxicity. Depending on the exposure level and the vulnerability of the populations, fungi may represent different public health risks. For example, damp and moldy dwellings are associated with chronic, respiratory diseases such as asthma and allergic rhinitis. However, the lack of valid tools for accurately measuring the environmental fungal exposure is one of the main challenges to better understanding the role of fungal products and particles in human health. In this thesis, diverse sampling techniques and analytical methods were evaluated for measuring the fungal contamination in the air, on surfaces and in settled dust. A quantitative PCR-based index was notably tested and compared with other approaches to assess fungal exposure in dwellings. By collecting and analyzing settled floor dust, this index successfully distinguished between contaminated and non-contaminated homes in Brittany, France. Quantitative PCR and this index are promising techniques for fungal exposure assessment in indoor environments. Further validation of these methods may lead to disease prevention approaches, particularly for vulnerable populations.
Les moisissures sont des micro-organismes présents dans tous les environnements intérieurs. Les effets sur la santé associés à ces champignons microscopiques sont multiples : irritations, réactions immunoallergiques, infections et effets toxiques. Selon le niveau d'exposition et la vulnérabilité des populations, les moisissures peuvent représenter des risques plus ou moins importants pour la santé publique. Les logements humides et moisis ont par exemple été associés à des maladies chroniques respiratoires telles que l'asthme et les rhinites allergiques. Cependant, le manque d'outils valides permettant d'évaluer quantitativement l'exposition fongique environnementale constitue une des principales difficultés pour mieux appréhender le rôle des particules et des composés fongiques sur la santé humaine. Lors de ce travail de thèse, diverses techniques d'échantillonnage et méthodes d'analyses ont été évaluées afin de mesurer la contamination fongique de l'air, des surfaces et des poussières. Un indice moléculaire basé sur la technique de PCR quantitative a notamment été testé et comparé à d'autres approches pour mesurer l'exposition fongique dans des logements. Après analyse des poussières domestiques collectées au sol, cet indice a permis de discriminer les habitats avec ou sans moisissures visibles. La quantification de groupes fongiques par PCR quantitative s'avère une technique prometteuse pour la mesure de l'exposition aux moisissures dans les environnements intérieurs. Outre le développement et la validation d'outils de mesure, une démarche globale de prévention du risque fongique semble nécessaire, particulièrement chez les populations vulnérables.
https://tel.archives-ouvertes.fr/tel-00768444

Droits : info:eu-repo/semantics/OpenAccess
tel-00768444
https://tel.archives-ouvertes.fr/tel-00768444
https://tel.archives-ouvertes.fr/tel-00768444/document
https://tel.archives-ouvertes.fr/tel-00768444/file/MA_heust_Delphine.pdf

Éditeur(s) : HAL CCSD Wiley Open Access
Résumé : International audience
Coral disease outbreaks have increased over the last three decades, but their causal agents remain mostly unclear (e.g., bacteria, viruses, fungi, protists). This study details a 14-month-long survey of coral colonies in which observations of the development of disease was observed in nearly half of the sampled colonies. A bimonthly qPCR method was used to quantitatively and qualitatively evaluate Symbiodinium assemblages of tagged colonies, and to detect the presence of Vibrio spp. Firstly, our data showed that predisposition to disease development in general, and, more specifically, infection by Vibrio spp. in Acropora cytherea depended on which clades of Symbiodinium were harbored. In both cases, harboring clade D rather than A was beneficial to the coral host. Secondly, the detection of Vibrio spp. in only colonies that developed disease strongly suggests opportunistic traits of the bacteria. Finally, even if sporadic cases of switching and probably shuffling were observed, this long-term survey does not suggest specific-clade recruitment in response to stressors. Altogether, our results demonstrate that the fitness of the coral holobiont depends on its initial consortium of Symbiodinium, which is distinct among colonies, rather than a temporary adaptation achieved through acquiring different Symbiodinium clades.
ISSN: 2045-7758

hal-01346931
https://hal-uvsq.archives-ouvertes.fr/hal-01346931
https://hal-uvsq.archives-ouvertes.fr/hal-01346931/document
https://hal-uvsq.archives-ouvertes.fr/hal-01346931/file/2016%20Rouze%20EcolEvol.pdf
DOI : 10.1002/ece3.1895