title: External Quality Assessment of MERS-CoV Molecular Diagnostics During the 2015 Korean Outbreak.
abstract: BACKGROUND
  The largest outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection outside Middle East Asia in 2015 has necessitated the rapid expansion of laboratories that conduct MERS-CoV molecular testing in Korea, together with external quality assessment (EQA) to evaluate the assays used.
  
  
  METHODS
  The EQA program consisted of two phases; self-validation and blind assessment. For the first EQA phase, in vitro transcribed upstream region of the envelope gene (upE) and the open reading frame (ORF)1a RNAs were used at a concentration of 1,000 copies/μL. The test panel for the second EQA phase consisted of RNA extracts from three samples, which were obtained from two MERS-CoV positive patients and one MERS-CoV negative patient.
  
  
  RESULTS
  The first EQA phase results for 46 participants showed a linear relationship between the threshold cycle (C(T)) values of RNA materials and the logarithmic concentrations for both upE and ORF1a gene targets (R²=0.73 and 0.75, respectively). The mean C(T) value for each concentration was different depending on which commercial kit was used for the assay. Among the three commonly used kits, PowerChek MERS Real-Time PCR kit (KogeneBiotech, Korea) showed the lowest C(T) values at all concentrations of upE and most concentrations of ORF1a. The second EQA phase results for 47 participants were 100% correct for all tested samples.
  
  
  CONCLUSIONS
  This EQA survey demonstrates that the MERS-CoV molecular testing performed in Korea during the 2015 outbreak is of robust capability. However, careful establishment and validation of a cut-off value are recommended to ensure good analytical sensitivity.
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Moon Woo
authors.initials: MW
authors.lastname: Seong
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Sung Im
authors.initials: SI
authors.lastname: Cho
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Kyungphil
authors.initials: K
authors.lastname: Ko
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Mi Na
authors.initials: MN
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Heungsub
authors.initials: H
authors.lastname: Sung
authors.affiliation: Department of Laboratory Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Jae Seok
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Ahn
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Byung Su
authors.initials: BS
authors.lastname: Yu
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Taek Soo
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Eui Chong
authors.initials: EC
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea. sparkle@snu.ac.kr.
authors.forename: Sung Sup
authors.initials: SS
authors.lastname: Park
mesh_terms: D018352:Coronavirus Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D004196:Disease Outbreaks; D006801:Humans; D065207:Middle East Respiratory Syndrome Coronavirus / Q000235:genetics* / Q000302:isolation & purification; D025202:Molecular Diagnostic Techniques / Q000592:standards*; D011785:Quality Assurance, Health Care; D012367:RNA, Viral / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D056910:Republic of Korea / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D012367:RNA, Viral
keywords: External quality assessment; MERS-CoV; Molecular diagnostics; ORF1a; Real-time PCR; upE