title: Precision of the Kalon Herpes Simplex Virus Type 2 IgG ELISA: an international inter-laboratory assessment.
abstract: The commercial Kalon HSV-2 IgG ELISA is currently recommended for research use in sub-Saharan Africa because of its superior accuracy compared to other serologic assays. However, there are no data on key precision parameters of Kalon such as inter-operator variation, repeatability, and reproducibility, thus contributing to a barrier for its acceptance and use in clinical trials in sub-Saharan Africa. We evaluated the analytical and field precision of the Kalon HSV-2 IgG ELISA.
  
  
  
  A total of 600 HIV-infected and uninfected serum samples from South Africa and Zambia, previously tested by the gold standard University of Washington HSV western blot (UW-WB), were tested using Kalon by two technologists in an United States reference laboratory. Aliquots of 183 samples were retested using Kalon by an on-site technologist in a South African laboratory and a Zambian laboratory.
  
  
  
  Intra-assay variation was below 10 %. Intra-assay, intra-laboratory, and inter-laboratory correlation and agreement were significantly high (p < 0.01). In comparison to the UW-WB, accurate performance of Kalon was reproducible by each operator and laboratory. Receiver operating characteristic curve analysis indicated high selectivity of Kalon in the overall study population (area under the curve = 0.95, 95%CI = 0.92-0.97).
  
  
  
  Kalon is a robust assay with high precision and reproducibility. Accordingly, operator errorlikely does not contribute to the variability observed in Kalon's specificity throughout sera from sub-Saharan Africa.
  
  
  
  In populations with optimal diagnostic accuracy, Kalon is a reliable stand-alone method for on-site HSV-2 IgG antibody detection.
authors.affiliation: Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Baltimore, MD, USA.
authors.forename: Eshan U
authors.initials: EU
authors.lastname: Patel
authors.affiliation: Department of Medicine, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Jordyn
authors.initials: J
authors.lastname: Manucci
authors.affiliation: Department of Epidemiology, University of Washington, Seattle, WA, USA.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Kahle
authors.affiliation: Departments of Medicine, Global Health, and Pediatrics, University of Washington, Seattle, WA, USA.
authors.forename: Jairam R
authors.initials: JR
authors.lastname: Lingappa
authors.affiliation: Department of Laboratory Medicine, University of Washington, Seattle, WA, USA.|Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: Rhoda Ashley
authors.initials: RA
authors.lastname: Morrow
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Estelle
authors.initials: E
authors.lastname: Piwowar-Manning
authors.affiliation: Department of Paediatrics and Child Health, Stellenbosch University, Stellenbosch, South Africa.
authors.forename: Anelet
authors.initials: A
authors.lastname: James
authors.affiliation: Zambart, Lusaka, Zambia.
authors.forename: Kwitaka F
authors.initials: KF
authors.lastname: Maluzi
authors.affiliation: Zambart, Lusaka, Zambia.
authors.forename: Maina M
authors.initials: MM
authors.lastname: Cheeba
authors.affiliation: Perinatal HIV Research Unit, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Glenda
authors.initials: G
authors.lastname: Gray
authors.forename: Barry
authors.initials: B
authors.lastname: Kosloff
authors.affiliation: Wits Reproductive Health and HIV Institute and University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Sinead
authors.initials: S
authors.lastname: Delany-Moretlwe
authors.affiliation: Zambia-Emory Research Project and Ndola Central Hospital, Ndola, Zambia.
authors.forename: Mubiana
authors.initials: M
authors.lastname: Inambao
authors.affiliation: Zambia-Emory Research Project, Lusaka, Zambia.
authors.forename: Bellington
authors.initials: B
authors.lastname: Vwalika
authors.affiliation: Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Baltimore, MD, USA.|Department of Medicine, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Quinn
authors.affiliation: Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Baltimore, MD, USA. olaeyen1@jhmi.edu.|Department of Medicine, Johns Hopkins University, Baltimore, MD, USA. olaeyen1@jhmi.edu.|NIAID, NIH and SOM, JHU, 855 North Wolfe St., Rangos Building, Room 538A, Baltimore, MD, 21205, USA. olaeyen1@jhmi.edu.
authors.forename: Oliver
authors.initials: O
authors.lastname: Laeyendecker
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D019540:Area Under Curve; D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D005260:Female; D015658:HIV Infections / Q000150:complications; D006558:Herpes Genitalis / Q000150:complications / Q000175:diagnosis* / Q000821:virology; D018258:Herpesvirus 2, Human / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007753:Laboratories / Q000592:standards*; D008297:Male; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G