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Ruvoen-Clouet N.,National School of Engineering in Agricultural and Food Industries | Ruvoen-Clouet N.,French Institute of Health and Medical Research | Belliot G.,Center National Of Reference Des Virus Enteriques | Le Pendu J.,French Institute of Health and Medical Research
Reviews in Medical Virology | Year: 2013

SUMMARY: Noroviruses (NoVs) are recognized as a leading cause of human gastroenteritis worldwide. Infection occurs following the ingestion of contaminated food or, most often, through direct contact from person to person. However, not all individuals are equally sensitive to these viruses. Indeed, NoVs use glycans of the ABH and Lewis histo-blood group antigen family (HBGAs) as attachment factors. At the epithelial level, the synthesis of these HBGAs requires the action of several glycosyltransferases that are encoded by the ABO, FUT2, and FUT3 genes. The combined polymorphism at these three loci dictates sensitivity to NoV infection because the attachment profile to these glycans varies among strains. Structural analysis of the capsid protein interaction with HBGAs reveals distinct modes of binding for strains of genogroups I and II but high conservation within each genogroup, whereas minor amino acid changes are sufficient to generate modifications of HBGA-binding specificities or affinities. Such modifications therefore induce changes in the spectrum of susceptible individuals. Studies of NoV-HBGA interactions together with phylogenetic analyses and the epidemiologic survey of strains indicate that NoV transmission and evolution depend on both the establishment of herd immunity and the genetic resistance of many individuals, which confers herd innate protection by restricting NoV circulation. © 2013 John Wiley & Sons, Ltd. Source


Barret A.S.,Institute of Veille Sanitaire | Jourdan-Da Silva N.,Institute of Veille Sanitaire | Ambert-Balay K.,Center National Of Reference Des Virus Enteriques | Delmas G.,Institute of Veille Sanitaire | And 4 more authors.
Eurosurveillance | Year: 2014

This article describes outbreaks of gastroenteritis in elderly long-term care facilities (LTCF) in France from November 2010 to May 2012 reported through the surveillance system for gastroenteritis outbreaks in LTCF. A total of 1,072 outbreaks were reported, causing 26,551 episodes of illness and 60 deaths. The median attack rate (AR) among residents was 32%. Norovirus and person-to-person transmission were the most frequently reported aetiology and mode of transmission. Control measures were implemented in 1,054 (98%) outbreaks and for 928 outbreaks, the timing of such measures could be inferred. Of these, 799 (86%) had put control measures into effect within three days of the occurrence of the first case. Outbreaks of gastroenteritis in LTCF cause substantial morbidity and mortality among elderly people in France. LTCF are encouraged to develop infection prevention and control plans and to notify any gastroenteritis outbreak to health authorities to ensure rapid control. © 2007-2013. All rights reserved. Source


Ruvoen-Clouet N.,National School of Engineering in Agricultural and Food Industries | Ruvoen-Clouet N.,University of Nantes | Belliot G.,Center National Of Reference Des Virus Enteriques | Le Pendu J.,University of Nantes
Virologie | Year: 2013

Norovirus (NoVs) are recognized as a leading cause of human gastroenteritis worldwide. Infection takes place following ingestion of contaminated food or most often through direct contact from person to person. However, not all individuals are equally sensitive to these viruses. Indeed, NoVs use ABH and Lewis glycans of the histo-blood group antigen family (HBGAs) as ligands. At the epithelial level synthesis of these HBGAs requires the action of several glycosyltransferases encoded by the ABO, FUT2 and FUT3 genes. Since the attachment profile to these glycans varies from strain to strain, the combined polymorphism at these three loci dictates sensitivity to NoV infection. Studies of the NoV-HBGA interactions together with phylogenetic analyses and the epidemiologic follow-up of strains indicate that NoVs transmission and evolution depends both on the establishment of herd immunity and on the genetic resistance of many individuals that contributes to restrict NoVs circulation, confering a herd innate proctection. Source


Pothier P.,Center National Of Reference Des Virus Enteriques
Bulletin de l'Academie Nationale de Medecine | Year: 2010

Rotaviruses and noroviruses are the main causes of acute gastroenteritis in young children and adults, respectively. Prospective molecular surveillance of rotavirus genotypes in France and Europe shows that circulating strains may vary with the season, locality or country. Rotavirus OK? genotypes G1 and G9 are the most prevalent. Most strains are associated with P[8], showing a certain genotypic stability of rotaviruses currently circulating in Europe and suggesting that vaccination would be effective at least in the short and medium -term. However, atypical strains G12 and G8 must be monitored in case they emerge in future. Noroviruses belong to the Caliciviridae family. These single-stranded RNA viruses show major genetic diversity: they are divided into 5 genogroups, which are themselves subdivided into genotypes. In addition, new variants are continually arising, and are frequently associated with new epidemic waves of gastroenteritis. Source


Roos-Weil D.,Center dInfectiologie Necker Pasteur | Ambert-Balay K.,Center National Of Reference Des Virus Enteriques | Lanternier F.,Center dInfectiologie Necker Pasteur | Lanternier F.,University of Paris Descartes | And 19 more authors.
Transplantation | Year: 2011

Background: Diarrhea of unspecified cause frequently occurs after renal transplantation and is usually ascribed to mycophenolic acid toxicity. Norovirus (NoV) and sapovirus (SaV) have been sporadically reported to cause chronic diarrhea in immunocompromised patients. Methods: We undertook a retrospective study (2008-2009) to examine the clinical and epidemiologic significance of NoV and SaV infections in adult renal transplant recipients hospitalized for acute or chronic diarrhea. Results: Ninety-six renal transplant recipients were hospitalized for diarrhea at our institution during a 16-month period, 87 of whom were included in the study, including 46 patients with chronic diarrhea. Among 41 patients with unexplained diarrhea, 20 patients were screened for NoV/SaV, 16 of whom were positive. Fifteen of them (94%) had chronic diarrhea. When compared with bacterial and parasitic infections, NoV/SaV infections were associated with a greater weight loss at the time of admission, a 8.7-fold longer duration of symptoms and a more frequent need for mycophenolic acid dosage reduction. Eighty-one percent of patients hospitalized for NoV/SaV-associated diarrhea experienced acute renal failure. Five and one patients subsequently had biopsy-diagnosed active graft rejection and oxalate nephropathy, respectively. Ten of the 14 patients who underwent a longitudinal study of NoV/SaV stool's clearance exhibited a prolonged viral shedding period with a median time of 289 days (107-581 days). Conclusions: Our study indicates that NoV/SaV infection causes posttransplant chronic diarrhea potentially complicated by severe kidney graft impairment. © 2011 by Lippincott Williams & Wilkins. Source

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