title: Multicenter Evaluation of the Xpert Norovirus Assay for Detection of Norovirus Genogroups I and II in Fecal Specimens.
abstract: Norovirus is the most common cause of sporadic gastroenteritis and outbreaks worldwide. The rapid identification of norovirus has important implications for infection prevention measures and may reduce the need for additional diagnostic testing. The Xpert Norovirus assay recently received FDA clearance for the detection and differentiation of norovirus genogroups I and II (GI and GII), which account for the vast majority of infections. In this study, we evaluated the performance of the Xpert Norovirus assay with both fresh, prospectively collected (n = 914) and frozen, archived (n = 489) fecal specimens. A Centers for Disease Control and Prevention (CDC) composite reference method was used as the gold standard for comparison. For both prospective and frozen specimens, the Xpert Norovirus assay showed positive percent agreement (PPA) and negative percent agreement (NPA) values of 98.3% and 98.1% for GI and of 99.4% and 98.2% for GII, respectively. Norovirus prevalence in the prospective specimens (collected from March to May of 2014) was 9.9% (n = 90), with the majority of positives caused by genogroup II (82%, n = 74). The positive predictive value (PPV) of the Xpert Norovirus assay was 75% for GI-positive specimens, whereas it was 86.5% for GII-positive specimens. The negative predictive values (NPV) for GI and GII were 100% and 99.9%, respectively.
authors.affiliation: Department of Pathology & Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Gonzalez
authors.affiliation: Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: L Claire
authors.initials: LC
authors.lastname: Langley
authors.affiliation: Department of Pathology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: Blake W
authors.identifier: http://orcid.org/0000-0002-4111-048X
authors.initials: BW
authors.lastname: Buchan
authors.affiliation: Department of Pathology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Faron
authors.affiliation: Institute of Virology, Leipzig University, Leipzig, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Maier
authors.affiliation: Specialist Virology Centre, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Kate
authors.initials: K
authors.lastname: Templeton
authors.affiliation: Department of Pathology, Scott and White Memorial Hospital, Temple, Texas, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Walker
authors.affiliation: Clinical Molecular Microbiology Laboratory, UNC Health Care, Chapel Hill, North Carolina, USA.
authors.forename: Elena B
authors.initials: EB
authors.lastname: Popowitch
authors.affiliation: Clinical Molecular Microbiology Laboratory, UNC Health Care, Chapel Hill, North Carolina, USA Department of Pathology and Laboratory Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
authors.forename: Melissa B
authors.initials: MB
authors.lastname: Miller
authors.affiliation: Department of Pathology, Scott and White Memorial Hospital, Temple, Texas, USA.
authors.forename: Arundhati
authors.initials: A
authors.lastname: Rao
authors.affiliation: Institute of Virology, Leipzig University, Leipzig, Germany.
authors.forename: Uwe G
authors.initials: UG
authors.lastname: Liebert
authors.affiliation: Department of Pathology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Ledeboer
authors.affiliation: Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Vinjé
authors.affiliation: Department of Pathology & Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, Missouri, USA cburnham@path.wustl.edu.
authors.forename: C A
authors.identifier: http://orcid.org/0000-0002-1137-840X
authors.initials: CA
authors.lastname: Burnham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017250:Caliciviridae Infections / Q000175:diagnosis* / Q000821:virology; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000821:virology*; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D029322:Norovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014773:Virology / Q000379:methods*; D055815:Young Adult