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Search Results: 1 - 10 of 160 matches for " Yoann Madec "
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Differential responses of the mosquito Aedes albopictus from the Indian Ocean region to two chikungunya isolates
Estelle Martin, Sara Moutailler, Yoann Madec, Anna-Bella Failloux
BMC Ecology , 2010, DOI: 10.1186/1472-6785-10-8
Abstract: We performed experimental infections using three mosquito strains of Ae. aegypti Mayotte and Ae. albopictus (Mayotte and Reunion), and two CHIKV strains (E1-226A and E1-226V). Ae. aegypti Mayotte were similarly susceptible to both viral strains, whereas Ae. albopictus Mayotte and Ae. albopictus Reunion were more susceptible to CHIKV E1-226V than to E1-226A. In terms of life-history traits measured by examining mosquito survival and reproduction, we found that: (1) differences were observed between responses of mosquito species to the two viruses, (2) CHIKV infection only affected significantly some life-history traits of Ae. albopictus Reunion and not of the other two mosquito strains, and (3) CHIKV reduced the lifespan of Ae. albopictus Reunion and shortened the time before egg laying.We demonstrated that CHIKV only reduces the survival of Ae. albopictus from the Reunion Island. By laying eggs just before death, reproduction of Ae. albopictus from the Reunion Island is not reduced since other parameters characterizing oviposition and hatching were not affected.Chikungunya virus (CHIKV) is an arbovirus (Togaviridae family, Alphavirus genus) transmitted by Aedes mosquito species, that usually induces an acute illness in humans characterized by fever, rash, and incapacitating arthralgia [1]. The virus was first described in Tanzania in 1952 [2]. In Africa, it has been maintained in a sylvatic cycle involving forest mosquitoes feeding preferentially on wild non-human primates [3,4]. The virus was later introduced into Asia where it circulates within an urban cycle; only an inter-human transmission cycle is described on this continent, involving Aedes aegypti and Aedes albopictus as vectors [5,6].In early 2005, CHIKV was introduced into the Indian Ocean region, probably by viremic travelers returning from Kenya where an outbreak had started in June 2004 [7]. Later, in 2005 and 2006, CHIKV spread across the Indian Ocean islands (Comoros, Madagascar, Mayotte, Seychelles,
Increased Risk of Q151M and K65R Mutations in Patients Failing Stavudine-Containing First-Line Antiretroviral Therapy in Cambodia
Janin Nouhin, Yoann Madec, Nicole Ngo-Giang-Huong, Laurent Ferradini, Eric Nerrienet
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0073744
Abstract: Background Multi-nucleos(t)ide resistance (MNR) mutations including Q151M, K65R mutations, and insertion at codon 69 of HIV-1 reverse transcriptase coding region may confer resistance to all molecules of nucleos(t)ide reverse transcriptase inhibitors (NRTI). The presence of these mutations is an emerging problem compromising non-nucleoside reverse transcriptase inhibitors and protease inhibitors-based therapies. Furthermore, factors associated with selection of these mutations are still not well defined. The current study aimed to evaluate the frequency and to characterize factors associated with the occurrence of multi-nucleos(t)ide resistance mutations among HIV-1 infected patients failing recommended first-line antiretroviral regimens in Cambodia. Methodology/Principal Finding This is a retrospective analysis of HIV-1 drug resistance genotyping of 520 HIV-1 infected patients in virological failure (viral load > 250 copies/mL) while on first-line antiretroviral therapy in Cambodia with at least one reverse transcriptase inhibitor resistance associated mutation. Among these 520 patients, a total of 66 subjects (66/520, 12.7%) presented ≥1 MNR mutation, including Q151M, K65R, and Insert69 for 59 (11.3%), 29 (5.6%), and 2 (0.4%) patients, respectively. In multivariate analysis, both Q151M (p = 0.039) and K65R (p = 0.029) mutations were independently associated with current stavudine- compared to zidovudine-use. Conclusion Such selection of mutations by stavudine drastically limits the choice of antiretroviral molecules available for second-line therapy in resource-limited settings. This finding supports the World Health Organization’s recommendation for stavudine phase-out.
Persistent Difficulties in Switching to Second-Line ART in Sub-Saharan Africa — A Systematic Review and Meta-Analysis
Yoann Madec, Sandrine Leroy, Marie-Anne Rey-Cuille, Florence Huber, Alexandra Calmy
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082724
Abstract: Objectives Switching to second-line antiretroviral therapy (ART) largely depends on careful clinical assessment and access to biological measurements. We performed a systematic review and meta-analysis to estimate the incidence of switching to second-line ART in sub-Saharan Africa and its main programmatic determinants. Methods We searched 2 databases for studies reporting the incidence rate of switching to second-line ART in adults living in sub-Saharan Africa. Data on the incidence rate of switching were pooled, and random-effect models were used to evaluate the effect of factors measured at the programme level on this incidence rate. Results Nine studies (157,340 patients) in 21 countries were included in the meta-analysis. All studies considered patients under first-line ART and conditions to initiate ART were similar across studies. Overall, 3,736 (2.4%) patients switched to second-line ART. Incidence rate of switch was in mean 2.65 per 100 person-years (PY) (95% confidence interval: 2.01–3.30); it ranged from 0.42 to 4.88 per 100 PY and from 0 to 4.80 per 100 PY in programmes with and without viral load monitoring, respectively. No factors measured at the programme level were associated with the incidence rate of switching to second-line ART. Conclusion The low incidence rate of switching to second-line ART suggests that the monitoring of patients under ART is challenging and that access to second-line ART is ineffective; efforts should be made to increase access to second-line ART to those in need by providing monitoring tools, education and training, as well as a more convenient regimen.
Simplified Assessment of Antiretroviral Adherence and Prediction of Virological Efficacy in HIV-Infected Patients in Cambodia
Olivier Segeral,Yoann Madec,Boroath Ban,Vara Ouk,Chan Roeurn Hak,Clotilde Le Tiec,Eric Nerrienet,Cécile Goujard,Anne Marie Taburet,Jean Francois Delfraissy,Arnaud Fontanet
AIDS Research and Treatment , 2010, DOI: 10.1155/2010/142076
Abstract: Background. Adherence to antiviral therapy is important for HIV-infected people living in low- and middle-income countries, because of poor access to alternative regimens. Methods. We conducted a cross-sectional survey of adherence in Cambodian patients enrolled in the ESTHER program and treated with WHO first-line regimen for at least 6 months. The survey was based on a self-report questionnaire, drug assay, MCV measurement, visual analog scale, and viral load HIV RNA. Results. Two hundred fifty-nine patients treated for a median of 16 months participated in the survey. At inclusion in the program, 158 patients (61%) were ARV-na?ve. The virological success rate was 71% overall and 81% in previously ARV-naive patients. Considered individually, the measures suggested perfect adherence in 71% to 93% of patients. In multivariate analysis adjusted for sex and therapeutic status before HAART initiation, only the biological markers were associated with virological efficacy. Self-funded treatment before entry to the program was highly predictive of virological failure. Conclusion. Adherence was excellent in these Cambodian patients. Biological markers were predictive of virological efficacy. MCV might thus serve as a simple alternative for assessing adherence and predicting virological efficacy among patients receiving AZT- or d4T-based regimens. 1. Introduction Since highly active antiretroviral therapy (HAART) became widely available in industrialized countries, mortality and morbidity among patients living with HIV/AIDS have been substantially reduced [1]. Recently, access to ARV has improved in low- and middle-income countries.In late 2007, three million people in such countries were receiving HAART [2]. Numerous initiatives have shown that countries such as Brazil, Thailand, and Senegal can provide HAART on a large scale by using produced generic drugs [3–5], and that smaller programs can provide HAART in local healthcare centres [6–10]. These cohort studies also demonstrated the efficacy of World Health Organization-(WHO-)recommended first-line HAART regimens, mainly thanks to excellent adherence to treatment [10–12]. It is particularly important to assess adherence during HAART programs, mainly owing to the limited availability of alternative regimens [13]. Indeed, poor adherence can lead to the emergence of drug resistance [14–16], notably to first-line nonnucleoside reverse transcriptase inhibitor (NNRTI-)based regimens recommended by WHO. In countries with poor access to laboratory monitoring (CD4 cell count and viral load), it has been suggested
HIV Prevalence and Impact on Renutrition in Children Hospitalised for Severe Malnutrition in Niger: An Argument for More Systematic Screening
Yoann Madec, David Germanaud, Violeta Moya-Alvarez, Wafa Alkassoum, Aichatou Issa, Morou Amadou, Stephanie Tchiombiano, Cecilia Pizzocolo, Florence Huber, Sanata Diallo, Roubanatou Abdoulaye-Mamadou
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0022787
Abstract: Background In developing countries, malnutrition is a contributing factor in over 50% of child deaths. Mortality rates are higher in underweight children, and HIV-infection is known to increase underweight. Our goals were to evaluate the prevalence of HIV among children hospitalised for severe malnutrition (SM) at the Niamey national hospital (Niger), and to compare renutrition and mortality by HIV-status. Methods Retrospective study based on all children <5 years hospitalised for SM between January 1st 2008 and July 1st 2009. HIV-prevalence was the ratio of HIV+ children on the number of children tested. Duration of renutrition and mortality were described using survival curves. Results During the study period, 477 children were hospitalised for SM. HIV testing was accepted in 470 (98.5%), of which 40 were HIV+ (HIV prevalence (95% confidence interval) of 8.6% (6.2–11.5)). Duration of renutrition was longer in HIV+ than HIV? children (mean: 22 vs. 15 days; p = 0.003). During renutrition, 8 (20%) and 61 (14%) HIV+ and HIV? children died, respectively (p = 0.81). Conclusion Around 9% of children hospitalised for severe malnutrition were HIV infected, while in Niger HIV prevalence in adults is estimated at 0.8%. This pleads for wider access to HIV testing in this population.
Cost-Effectiveness of Primary Prophylaxis of AIDS Associated Cryptococcosis in Cambodia
Romain Micol,Ayden Tajahmady,Olivier Lortholary,Suna Balkan,Catherine Quillet,Jean-Philippe Dousset,Hak Chanroeun,Yoann Madec,Arnaud Fontanet,Yazdan Yazdanpanah
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0013856
Abstract: Cryptococcal infection is a frequent cause of mortality in Cambodian HIV-infected patients with CD4+ count ≤100 cells/μl. This study assessed the cost-effectiveness of three strategies for cryptococcosis prevention in HIV-infected patients.
Imported Amoebic Liver Abscess in France
Hugues Cordel,Virginie Prendki,Yoann Madec,Sandrine Houze,Luc Paris,Patrice Bourée,Eric Caumes,Sophie Matheron,Olivier Bouchaud ,the ALA Study Group
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002333
Abstract: Background Worldwide, amoebic liver abscess (ALA) can be found in individuals in non-endemic areas, especially in foreign-born travelers. Methods We performed a retrospective analysis of ALA in patients admitted to French hospitals between 2002 and 2006. We compared imported ALA cases in European and foreign-born patients and assessed the factors associated with abscess size using a logistic regression model. Results We investigated 90 ALA cases. Patient median age was 41. The male:female ratio was 3.5:1. We were able to determine the origin for 75 patients: 38 were European-born and 37 foreign-born. With respect to clinical characteristics, no significant difference was observed between European and foreign-born patients except a longer lag time between the return to France after traveling abroad and the onset of symptoms for foreign-born. Factors associated with an abscess size of more than 69 mm were being male (OR = 11.25, p<0.01), aged more than 41 years old (OR = 3.63, p = 0.02) and being an immigrant (OR = 11.56, p = 0.03). Percutaneous aspiration was not based on initial abscess size but was carried out significantly more often on patients who were admitted to surgical units (OR = 10, p<0.01). The median time to abscess disappearance for 24 ALA was 7.5 months. Conclusions/Significance In this study on imported ALA was one of the largest worldwide in terms of the number of cases included males, older patients and foreign-born patients presented with larger abscesses, suggesting that hormonal and immunological factors may be involved in ALA physiopathology. The long lag time before developing ALA after returning to a non-endemic area must be highlighted to clinicians so that they will consider Entamoeba histolytica as a possible pathogen of liver abscesses more often.
Afficher la couleur : le rouge
Annick Madec
Amnis , 2010, DOI: 10.4000/amnis.333
Abstract: En 2004, des travaux de sociologie politique confirment ce que de nombreux témoins pensaient depuis plusieurs années : le peuple, qui dans l’histoire politique fran aise a longtemps représenté une partie de la solution de la question sociale, n’est plus qu’un problème. Celles et ceux qui se pensent comme appartenant au peuple, n’écoutent pas sans impatience les discours de disqualification. Cet article se propose d’observer ce que James C. Scott appelle un fragment de discours subalterne. Il s’agit d’écouter les discours caustiques d’une retraitée qui défend la dignité de la classe ouvrière, et notamment la dignité de ceux du peuple qui ont participé à écrire l’Histoire. Elle résiste à la perte d’estime de soi et de son groupe d’appartenance par la connaissance de l’histoire politique et sociale et répond dans son aire de voisinage aux discours dominants en s’appuyant sur ses connaissances et expériences. In 2004 researches in political science strenghten the earlier thought of numerous witnesses: the people (i.e. the working class people), which has been seen for long in French political life as an answer to the social problem , is seen to-day only as a problem. Men and women who think of themselves as members of the people don’t listen without some impatience to the discourses that bring discredit on them. This paper offers to examine what James C. Scott calls a piece of subaltern discourse. It’s a matter of listening to the caustic talks of a retired woman, who stands for the dignity of the working class, notably of those in the people who contributed in writing History. She resists the loss of self-esteem and peer-group thanks to the knowledge of social and political history and she relies to her own knowledge and experiences to tackle in the neighbourhood the dominant discourses. En 2004, los estudios de sociología política ratificaron lo que numerosos testigos pensaban desde hace varios a os: el pueblo, que en la historia política francesa ha sido presentado durante mucho tiempo como parte de la solución a la temática social, hoy en día solamente es percibido como un problema. Los hombres y mujeres que se consideran como parte del pueblo escuchan con desconcierto los discursos en los cuales se descalifica aquello que fue tan venerado. Este artículo propone observar lo que James C. Scott denominaba un fragmento del discurso subalterno. Se trata en particular de los discursos sarcásticos de una jubilada que defiende la dignidad de la clase obrera, y en particular de aquella parte del pueblo que participó en la escritura de la Historia
Dynamic Shift from CD85j/ILT-2 to NKG2D NK Receptor Expression Pattern on Human Decidual NK during the First Trimester of Pregnancy
Romain Marlin, Marion Duriez, Nadia Berkane, Claire de Truchis, Yoann Madec, Marie-Anne Rey-Cuille, Jean-Saville Cummings, Claude Cannou, Heloise Quillay, Fran?oise Barré-Sinoussi, Marie-Thérèse Nugeyre, Elisabeth Menu
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030017
Abstract: During the first trimester of human pregnancy, Natural Killer (NK) cells of the maternal uterine mucosa (e.g. decidua) have a unique phenotype and are involved in crucial physiological processes during pregnancy. We investigated whether modifications of the NK receptor repertoire occur during the first trimester of pregnancy. We found significantly decreased expression of KIR2DL1/S1 and KIR2DL2/L3/S2 receptors, NKp30 and NKp44 activatory receptors, and the CD85j (ILT-2) inhibitory receptor. We also observed significantly increased expression of the NKG2D activatory receptor at the decidual NK cell surface. By flow cytometry, we further highlighted an evolution of NK subsets between 8 and 12 weeks of gestation, with a shift from the KIR2DL1/S1+/KIR2DL2/L3/S2+ subset towards the double negative subset, coupled with a decrease of the CD85j+/NKG2D? subset in favour of the CD85j?/NKG2D+ subset. Furthermore, cell surface expression of NK receptor ligands, including CD85j and NKG2D ligands, has been characterized by flow cytometry on decidual immune CD14+ and CD3+ cells. HLA-G, the high affinity ligand of CD85j, was detected on both cell types. In contrast, NKG2D ligands ULBP-2 ULBP-3 and MICA/B were not expressed on CD14+ and CD3+ cells, however a variable expression of ULBP-1 was observed. The ligand expression of KIR2DL1/S1 and KIR2DL2/L3/S2 was also analyzed: the HLA-C molecule was expressed at a low level on some CD14+ cells whereas it was not detected on CD3+ cell surface. NK receptor ligands are known to be also expressed on the invading placental trophoblast cells. Thus, the phenotypic evolutions of decidual NK cells described in this present study may preserve their activation/inhibition balance during the first trimester of pregnancy.
Chikungunya Virus-associated Long-term Arthralgia: A 36-month Prospective Longitudinal Study
Clémentine Schilte equal contributor,Frédérik Staikovsky equal contributor,Thérèse Couderc equal contributor,Yoann Madec,Florence Carpentier,Somar Kassab,Matthew L. Albert,Marc Lecuit ? ,Alain Michault ?
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002137
Abstract: Background Arthritogenic alphaviruses, including Chikungunya virus (CHIKV), are responsible for acute fever and arthralgia, but can also lead to chronic symptoms. In 2006, a Chikungunya outbreak occurred in La Réunion Island, during which we constituted a prospective cohort of viremic patients (n = 180) and defined the clinical and biological features of acute infection. Individuals were followed as part of a longitudinal study to investigate in details the long-term outcome of Chikungunya. Methodology/Principal Findings Patients were submitted to clinical investigations 4, 6, 14 and 36 months after presentation with acute CHIKV infection. At 36 months, 22 patients with arthralgia and 20 patients without arthralgia were randomly selected from the cohort and consented for blood sampling. During the 3 years following acute infection, 60% of patients had experienced symptoms of arthralgia, with most reporting episodic relapse and recovery periods. Long-term arthralgias were typically polyarthralgia (70%), that were usually symmetrical (90%) and highly incapacitating (77%). They were often associated with local swelling (63%), asthenia (77%) or depression (56%). The age over 35 years and the presence of arthralgia 4 months after the disease onset are risk factors of long-term arthralgia. Patients with long-term arthralgia did not display biological markers typically found in autoimmune or rheumatoid diseases. These data helped define the features of CHIKV-associated chronic arthralgia and permitted an estimation of the economic burden associated with arthralgia. Conclusions/Significance This study demonstrates that chronic arthralgia is a frequent complication of acute Chikungunya disease and suggests that it results from a local rather than systemic inflammation.
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