title: The diagnostic accuracy of three rapid diagnostic tests for typhoid fever at Chittagong Medical College Hospital, Chittagong, Bangladesh.
abstract: OBJECTIVE
  To determine the diagnostic accuracy of three rapid diagnostic tests (RDTs) for typhoid fever in febrile hospitalised patients in Bangladesh.
  
  
  METHODS
  Febrile adults and children admitted to Chittagong Medical College Hospital, Bangladesh, were investigated with Bact/Alert(®) blood cultures and real-time PCR to detect Salmonella enterica Typhi and Paratyphi A and assays for Rickettsia, leptospirosis and dengue fever. Acute serum samples were examined with the LifeAssay (LA) Test-it™ Typhoid IgM lateral flow assay detecting IgM antibodies against S. Typhi O antigen, CTKBiotech Onsite Typhoid IgG/IgM Combo Rapid-test cassette lateral flow assay detecting IgG and IgM antibodies against S. Typhi O and H antigens and SD Bioline line assay for IgG and IgM antibodies against S. Typhi proteins.
  
  
  RESULTS
  In 300 malaria smear-negative febrile patients [median (IQR) age of 13.5 (5-31) years], 34 (11.3%) had confirmed typhoid fever: 19 positive by blood culture for S. Typhi (three blood PCR positive) and 15 blood culture negative but PCR positive for S. Typhi in blood. The respective sensitivity and specificity of the three RDTs in patients using a composite reference standard of blood culture and/or PCR-confirmed typhoid fever were 59% and 61% for LifeAssay, 59% and 74% for the CTK IgM and/or IgG, and 24% and 96% for the SD Bioline RDT IgM and/or IgG. The LifeAssay RDT had a sensitivity of 63% and a specificity of 91% when modified with a positive cut-off of ≥2+ and analysed using a Bayesian latent class model.
  
  
  CONCLUSIONS
  These typhoid RDTs demonstrated moderate diagnostic accuracies, and better tests are needed.
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Rapeephan R
authors.initials: RR
authors.lastname: Maude
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases and Center for Infection and Immunity Amsterdam (CINIMA), Amsterdam, The Netherlands.|Center for Experimental Molecular Medicine (CEMM), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Hanna K
authors.initials: HK
authors.lastname: de Jong
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Lalith
authors.initials: L
authors.lastname: Wijedoru
authors.affiliation: Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
authors.forename: Masako
authors.initials: M
authors.lastname: Fukushima
authors.affiliation: Chittagong Medical College Hospital, Chittagong, Bangladesh.
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Ghose
authors.affiliation: Chittagong Medical College Hospital, Chittagong, Bangladesh.
authors.forename: Rasheda
authors.initials: R
authors.lastname: Samad
authors.affiliation: Chittagong Medical College Hospital, Chittagong, Bangladesh.
authors.forename: Mohammed Amir
authors.initials: MA
authors.lastname: Hossain
authors.affiliation: Chittagong Medical College Hospital, Chittagong, Bangladesh.
authors.forename: Mohammed Rezaul
authors.initials: MR
authors.lastname: Karim
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.|Centre for Specialized Care and Research, Chittagong, Bangladesh.
authors.forename: Mohammed Abul
authors.initials: MA
authors.lastname: Faiz
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.|Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.|London School of Hygiene and Tropical Medicine, London, UK.|School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Parry
mesh_terms: D000293:Adolescent; D000328:Adult; D001459:Bangladesh; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000175:diagnosis; D003955:Diagnostic Tests, Routine / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007922:Leptospirosis / Q000175:diagnosis; D008297:Male; D012281:Rickettsia / Q000302:isolation & purification*; D019779:Salmonella enterica / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D014435:Typhoid Fever / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: Fiebre tifoidea; PCR a tiempo real; PCR en temps réel; Salmonella enterica serovar Typhi; Salmonella enterica serovar typhi; Salmonella enterica sérotype typhi; blood culture; cultivo de sangre; culture de sang; diagnostic accuracy; fièvre typhoïde; precisión diagnóstica; prueba de diagnóstico rápido; précision diagnostique; rapid diagnostic tests; real-time PCR; tests de diagnostic rapide; typhoid fever