22 research outputs found
Three cases of severe subfulminant hepatitis in heart-transplanted patients after nosocomial transmission of a mutant hepatitis B virus
Fulminant and severe viral hepatitis are frequently associated with mutant hepatitis B virus (HBV) strains. In this study, the genetic background of a viral strain causing severe subfulminant outcome in heart-transplanted patients was studied and compared with viral hepatitis B strains that were not linked to severe liver disease in the same setting. A total of 46 patients infected nosocomially with HBV genotype A were studied. Five different viral strains were detected, infecting 3, 9, 5, 24, and 5 patients, respectively. Only one viral strain was found to be associated with the subfulminant outcome and 3 patient deaths as a consequence of severe liver disease. The remaining 43 patients with posttransplantation HBV infection did not show this fatal outcome. Instead, symptoms of hepatitis were generally mild or clinically undiagnosed. Comparison of this virus genome with the four other strains showed an accumulation of mutations in the basic core promoter, a region that influences viral replication, but also in hepatitis B X protein (HBX) (7 mutant motifs), core (10 mutant motifs), the preS1 region (5 mutant motifs), and the HBpolymerase open reading frame (17 motifs). Some of these variations, such as those in the core region, were located on the tip of the protruding spike of the viral capsid (codons 60 to 90), also known in part as an important HLA class II-restricted epitope region. These mutations might therefore influence the immune-mediated response. The viral strain causing subfulminant hepatitis was, in addition, the only strain with a preCore stop codon mutation and, thus, hepatitis B e antigen (HBeAg) expression was never observed. The combination of these specific viral factors is thought to be responsible for the fatal outcome in these immune-suppressed heart-transplant recipients
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
Mangrove sediment carbon stocks along an elevation gradient : influence of the late Holocene marine regression (New Caledonia)
International audienceAmong blue carbon ecosystems, mangroves are very efficient in storing carbon in their sediments over decadal to millennial time scales. However, this ability varies with numerous parameters, including climate and sea-level variations. In New Caledonia, mangrove ecosystems develop in semi-arid conditions with a typical zonation: Rhizophora spp. colonize the seaward side of the intertidal area, while Avicennia marina develops at higher elevations, just below the salt-flat. Within this context, we determined both the quantity (organic carbon content and carbon stocks) and the characteristics (carbon over nitrogen ratios (C/N), stable carbon and nitrogen isotopes, radiocarbon age) of the organic matter stored beneath each mangrove stands. Carbon stocks were determined down to different limits with depth: approximate extension of the root systems, one-meter depth, and the hard substrate. Within the extension of the root systems, the sediment carbon stock was lower than 100 MgC ha−1 regardless of the mangrove species. This low value resulted directly from the dry climate that limits mangrove productivity. At depth beneath every zone, a buried layer enriched in mangrove-derived organic matter, with C/N values around 40 and δ13C values around −26‰ was observed. This layer likely resulted from a sea-level high stand during the late Holocene that allowed a long period of stability of the mangrove, slowly accumulating organic matter within the sediment. In this buried layer, the carbon stock was higher than in the upper sediment and reached up to 665, 255 and 300 MgC ha−1 in the salt-flat zone, the A. marina stand and the R. spp. stand, respectively. The highest stock, determined beneath the salt-flat, was suggested to be related to a period of sea-level stability that lasted ~3000 years, whereas beneath the other zones, which are at lower elevations, mangrove colonization was more recent and the sea-level was continuously decreasing till recently. Sea-level variations, and, specifically current sea-level rise, may strongly influence mangrove development due to their migration along the tidal elevation gradient to maintain the biotic conditions needed for their development
Virological and epidemiological features of hepatitis delta infection among blood donors in Nouakchott, Mauritania
International audienceBackgroundIn Mauritania, some authors have described a possible high prevalence of hepatitis delta virus (HDV) infection in the 1990s in studies of small-size samples. Objectives The aims of our study were to assess the prevalence of HDV in HBsAg positive blood donors in Mauritania, to identify the main risk factors for HDV transmission and to analyze genetic diversity of HDV strains. Study design From October 2008 to December 2009, 11,100 consecutive blood donors were considered in this study. Among them, 1700 (15.3%) were HBsAg positive and 455 accepted to participate in this study. Demographic, epidemiological, ethnical, clinical and biological data were recorded. HDV screening, i.e., antibodies (HDVAb) and RNA (HDV-RNA) detection, was performed for all of them as well as HDV and HBV genotyping. Results Ninety/455 (19.78%) donors were HDVAb positive and HDV-RNA was detectable in 56 (62.2%) of them. HDV infection was significantly associated with older age, number of marriages, military profession, residence in the desert and a history of hospitalization. The HDV genotypes of the circulating strains were HDV-1 (89.3%) and HDV-5 (10.7%). Conclusion HDV is highly endemic in Mauritanian blood donors indicating that a high number of them will develop chronic hepatitis, cirrhosis or hepatocellular carcinoma. Associated risk factors support nosocomial transmission of HDV. These data underline the need to reinforce HBV vaccination in newborns and in blood donors without HBV markers, together with screening for HDV in HBV-infected individuals.</p
Transmission nosocomiale du virus de l'hépatite B chez les malades après transplantation cardiaque: mise en évidence du rôle des biopsies endomyocardiques
International audienceOBJECTIVES: A high prevalence of chronic hepatitis B has been previously reported in heart transplant recipients in our center. Nosocomial transmission of hepatitis B has been therefore suggested. The aim of the present study was to investigate an outbreak of hepatitis B infection in heart transplant recipients and to to look for nosocomial acquisition of hepatitis B in these patients. METHODS: In a retrospective case-control study, review of transvenous endomyocardial biopsy (TEB) procedure, line probe assay and DNA sequencing for characterization of the outbreak isolate genotypes were performed in order to assess the possible risk of nosocomial transmission of hepatitis B in the setting of heart transplantation. Case was defined as a patient negative for HBsAg before heart transplantation and positive after. Controls were matched with cases by date of transplantation and time-interval of HBV infection occurrence in the cases patients. RESULTS: Transmission of HBV was associated with the number of HBsAg positive patients undergoing TEB the same day and in the same ward (OR=1.17, per additional encounter; 95%CI=1.01-1.37, P=0.02) and with the total number of TEB undergone after a HBsAg positive patient (OR=1.43 for additional encounter, 95%CI=0.97-2.1, P=0.056) but not with the number of biopsies. The virological study identified eight different strains. No common devices nor gloves, drapes, or medical solution were shared among patients during TEB. One staff member, but no surgeon, was HBsAg positive. No further case occurred after implementation of control measures. CONCLUSIONS: Patient-to-patient transmission during TEB sessions was demonstrated by the virological and the case-control studies. This transmission occurred without evidence of blood contact through vials or devices. There is strong evidence that this transmission may be due to the spread of infective blood droplets on the environmental surfaces and the material during the TEB procedure.ButsUne prévalence élevée d'hépatite chronique B a été rapportée après transplantation cardiaque dans notre centre. Des travaux de notre groupe ont émis l'hypothèse d'une transmission nosocomiale de l'infection par le virus de l'hépatite B chez ces malades. Le but de cette étude était d'étudier une épidémie d'hépatite B chez les malades transplantés cardiaques de notre centre et de démontrer le caractère nosocomial de cette épidémie.MéthodesLors de cette étude rétrospective cas contrôles la procédure des biopsies myocardiques trans-veineuses (BTV) a été revue. Une analyse moléculaire avec caractérisation des isolats et des génotypes a été effectuée dans le but d'évaluer la possibilité d'une transmission nosocomiale de l'infection par le virus de l'hépatite B dans le contexte de la transplantation cardiaque. Les cas index étaient définis comme des malades antigène HBs négatif avant la transplantation et positif après. Les malades contrôles ont été appariés avec les cas index pour la date de la transplantation cardiaque et l'intervalle entre la greffe et l'apparition de l'antigène HBs chez les cas index.RésultatsLa transmission de l'infection par le virus de l'hépatite B était associée de façon significative avec le nombre de patients Antigène HBs positif ayant eu une BTV le même jour et dans la même salle de cathétérisme (OR = 1,17; IC 95 % 1,01-1,37, P = 0,02) et avec le nombre total de BTV réalisées après un malade antigène HBs positif (OR = 1,43; IC 95 % = 0,97-2,1, P = 0,056) mais pas avec le nombre de biopsies. L'analyse virologique a identifié 8 souches différentes. Aucun partage de linge, de matériels solides ou de perfusion n'a eu lieu entre les malades pendant les BTV. Un membre de l'équipe soignante était positif pour l'antigène HBs mais aucun chirurgien ne l'était. Après l'institution de mesures d'hygiène drastique aucune nouvelle contamination n'est apparue.ConclusionUne transmission de malade à malade de l'infection par le virus de l'hépatite B survenant lors des BTV a été documentée par l'analyse virologique et l'étude de cas témoins. Cette transmission a eu lieu en l'absence de contact sanglant direct ou indirect. Il existe une forte présomption d'une contamination liée à la dissémination de particules contaminantes sur les surfaces ou le matériel durant les BTV
Epidemiology, management and risk factors for death of invasive Candida infections in critical care units: a multicenter, prospective, observational study in France (2005-2006)
International audienceOBJECTIVE: To describe the evolving epidemiology, management, and risk factors for death of invasive Candida infections in intensive care units (ICUs). DESIGN: Prospective, observational, national, multicenter study. SETTING: One hundred eighty ICUs in France. PATIENTS: Between October 2005 and May 2006, 300 adult patients with proven invasive Candida infection who received systemic antifungal therapy were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred seven patients (39.5%) with isolated candidemia, 87 (32.1%) with invasive candidiasis without documented candidemia, and 77 (28.4%) with invasive candidiasis and candidemia were eligible. In 37% of the cases, candidemia occurred within the first 5 days after ICU admission. C. albicans accounted for 57.0% of the isolates, followed by C. glabrata (16.7%), C. parapsilosis (7.5%), C. krusei (5.2%), and C. tropicalis (4.9%). In 17.1% of the isolates, the causative Candida was less susceptible or resistant to fluconazole. Fluconazole was the empirical treatment most commonly introduced (65.7%), followed by caspofungin (18.1%), voriconazole (5.5%), and amphotericin B (3.7%). After identification of the causative species and susceptibility testing results, treatment was modified in 86 patients (31.7%). The case fatality ratio in ICU was 45.9% and did not differ significantly according to the type of episode. Multivariate analysis showed that factors independently associated with death in ICU were type 1 diabetes mellitus (odds ratio [OR] 4.51; 95% confidence interval [CI] 1.72-11.79; p = 0.002), immunosuppression (OR 2.63; 95% CI 1.35-5.11; p = 0.0045), mechanical ventilation (OR 2.54; 95% CI 1.33-4.82; p = 0.0045), and body temperature >38.2 degrees C (reference, 36.5-38.2 degrees C; OR 0.36; 95% CI 0.17-0.77; p = 0.008). CONCLUSIONS: More than two thirds of patients with invasive candidiasis in ICU present with candidemia. Non-albicans Candida species reach almost half of the Candida isolates. Reduced susceptibility to fluconazole is observed in 17.1% of Candida isolates. Mortality of invasive candidiasis in ICU remains high
Impact of hepatitis B and delta virus co-infection on liver disease in Mauritania: a cross sectional study.
International audienceOBJECTIVES: Mauritania is a highly endemic region for hepatitis B (HBV) and delta (HDV) viruses. No data are available on HDV's impact on the severity of liver disease in consecutive HBV-infected patients in Africa. This study evaluated the degree of liver fibrosis in a cohort of chronic HBV carriers.METHODS: Three-hundred consecutive HBV-infected Mauritanian patients were checked for HDV infection via the detection of anti-HDV antibodies (Ab) and viral RNA. HBV- vs. HBV/HDV-infected patients were compared by physical examination, biological analyses, and the APRI (aspartate aminotransferase to platelet ratio index) and FibroMeter tests for determination of liver fibrosis.RESULTS: More than 30% of the patients had anti-HDVAb. Among these, 62.2% were HDV-RNA positive. Co-infected patients were older (>8-years) than HBV-mono-infected patients. They had more liver tests abnormalities and clinical or ultrasound signs of liver fibrosis. APRI and FibroMeter scores were also significantly increased in these patients. In multivariate analysis, beyond HDVAb, male gender and HBV-VL >3.7 log IU/mL were the only markers linked to significant liver fibrosis.CONCLUSIONS: In Mauritania, HDV co-infection worsens liver disease, both clinically and biologically, as confirmed by the APRI and FibroMeter tests. These tests may be useful for the management of delta hepatitis, which is a major health problem in Mauritania.</p
Multiple Sclerosis: Is There a Risk of Worsening after Yellow Fever Vaccination?
Background: Yellow fever vaccine (YFV) is not advised for multiple sclerosis (MS) patients because of the potential risk of post-vaccine relapses. Objective: To assess the risk of relapsing-remitting multiple sclerosis (RR-MS) worsening after YFV. Methods: Non-interventional observational retrospective, exposed/non-exposed cohort study nested in the French national cohort including MS. Results: 128 RR-MS were included. The 1-year annualized relapse rate (ARR) following YFV did not differ between exposed: 0.219 (0.420) and non-exposed subjects: 0.208 (0.521) ( p\,= 0.92). Time to first relapse was not different between groups (adjusted hazard ratio (HR) = 1.33; 95% confidence interval (CI) = 0.53\textendash 3.30, p = 0.54). Conclusion: These results suggest that YFV does not worsen the course of RR-MS
Towards a general perspective on life-history evolution and diversification in parasitoid wasps
In attempting to explain the marked interspecific variation evident in many components of life-history in parasitoid wasps, biologists have sought to identify general predictors of suites of ‘important’ life-history traits. Two predictors currently in general use are: (1) the parasitoid mode of larval development in relation to future host growth and development [no further host growth and development (= idiobiosis) versus continued host growth and development (= koinobiosis)]; and (2) the ovigeny index (the degree to which the lifetime potential complement of eggs is mature at the start of adult life in females). These have been postulated to share several life-history correlates, and an earlier comparative analysis showed the predictors to be associated. Two questions are thus posed: which life-history variables are actually common to both idio/koinobiosis and the ovigeny index, and which are responsible for the link between these two axes of life-history diversity? Through comparative analyses of a database of life-history traits for 133 parasitoid wasp species, four life-history correlates out of the 11 we investigated are shown to account for the association between the two predictors: the relative level of resource investment per egg (degree of yolk richness, which is lower in koinobionts), pre-adult lifespan (longer in koinobionts), female lifespan (shorter in koinobionts), and maximum egg load (larger in koinobionts). Our findings pave the way for full integration of the dichotomous hypothesis with the ovigeny index hypothesis, to provide a holistic perspective on parasitoid wasp life-history diversity and evolution