title: Clinical Evaluation of Rapid Diagnostic Test Kit for Scrub Typhus with Improved Performance.
abstract: Diagnosis of scrub typhus is challenging due to its more than twenty serotypes and the similar clinical symptoms with other acute febrile illnesses including leptospirosis, murine typhus and hemorrhagic fever with renal syndrome. Accuracy and rapidity of a diagnostic test to Orientia tsutsugamushi is an important step to diagnose this disease. To discriminate scrub typhus from other diseases, the improved ImmuneMed Scrub Typhus Rapid Diagnostic Test (RDT) was evaluated in Korea and Sri Lanka. The sensitivity at the base of each IgM and IgG indirect immunofluorescent assay (IFA) in Korean patients was 98.6% and 97.1%, and the specificity was 98.2% and 97.7% respectively. The sensitivity and specificity for retrospective diagnosis at the base of IFA in Sri Lanka was 92.1% and 96.1%. ImmuneMed RDT was not reactive to any serum from seventeen diseases including hemorrhagic fever with renal syndrome (n = 48), leptospirosis (n = 23), and murine typhus (n = 48). ImmuneMed RDT shows superior sensitivity (98.6% and 97.1%) compared with SD Bioline RDT (84.4% at IgM and 83.3% at IgG) in Korea. The retrospective diagnosis of ImmuneMed RDT exhibits 94.0% identity with enzyme-linked Immunosorbent assay (ELISA) using South India patient serum samples. These results suggest that this RDT can replace other diagnostic tests and is applicable for global diagnosis of scrub typhus. This rapid and accurate diagnosis will be beneficial for diagnosing and managing scrub typhus.
authors.affiliation: Institute of Medical Science, School of Medicine, Hallym University, Chuncheon, Korea .
authors.forename: Young-Jin
authors.identifier: 0000-0003-1996-9367
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Institute of Medical Science, School of Medicine, Hallym University, Chuncheon, Korea .
authors.forename: Sungman
authors.identifier: 0000-0002-6105-7129
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Medicine, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka .
authors.forename: Ranjan
authors.identifier: 0000-0002-6588-9467
authors.initials: R
authors.lastname: Premaratna
authors.affiliation: Department of Microbiology, Mahatma Gandhi Medical College & Research Institute, Pondicherry, India .
authors.forename: Stephen
authors.identifier: 0000-0003-0103-4061
authors.initials: S
authors.lastname: Selvaraj
authors.affiliation: Institute of Medical Science, School of Medicine, Hallym University, Chuncheon, Korea .
authors.forename: Sang-Jin
authors.identifier: 0000-0002-4838-2664
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Institute of Medical Science, School of Medicine, Hallym University, Chuncheon, Korea .
authors.forename: Sora
authors.identifier: 0000-0002-5314-2569
authors.initials: S
authors.lastname: Kim
authors.affiliation: Institute of Medical Science, School of Medicine, Hallym University, Chuncheon, Korea .
authors.forename: Donghwan
authors.identifier: 0000-0001-5881-9105
authors.initials: D
authors.lastname: Kim
authors.affiliation: Institute of Medical Science, School of Medicine, Hallym University, Chuncheon, Korea .
authors.forename: Min Soo
authors.identifier: 0000-0001-7489-3532
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Hallym University College of Medicine, Chuncheon, Korea .
authors.forename: Dong Hoon
authors.identifier: 0000-0002-3513-6333
authors.initials: DH
authors.lastname: Shin
authors.affiliation: Department of Pathology, Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon, Korea .
authors.forename: Kyung-Chan
authors.identifier: 0000-0001-6134-8631
authors.initials: KC
authors.lastname: Choi
authors.affiliation: Department of Infectious Diseases, Research Center for Infectious & Environmental Diseases, Armed Forces Medical Research Institute, Daejeon, Korea .
authors.forename: Soon-Hwan
authors.identifier: 0000-0002-1582-303X
authors.initials: SH
authors.lastname: Kwon
authors.affiliation: Agency for Defense Development, Institute of Civil-Military Technology Cooperation, Daejeon, Korea .
authors.forename: Wonjun
authors.identifier: 0000-0002-7109-3799
authors.initials: W
authors.lastname: Seo
authors.affiliation: National Biodefense Research Institute, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea .
authors.forename: Nam Taek
authors.identifier: 0000-0002-8352-4760
authors.initials: NT
authors.lastname: Lee
authors.affiliation: ImmuneMed, Chuncheon, Korea .
authors.forename: Seung-Han
authors.identifier: 0000-0003-1310-8136
authors.initials: SH
authors.lastname: Kim
authors.affiliation: ImmuneMed, Chuncheon, Korea .
authors.forename: Heui Keun
authors.identifier: 0000-0002-3216-4961
authors.initials: HK
authors.lastname: Kang
authors.affiliation: Institute of Medical Science, School of Medicine, Hallym University, Chuncheon, Korea.; Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Korea.
authors.forename: Yoon-Won
authors.identifier: 0000-0002-2242-2664
authors.initials: YW
authors.lastname: Kim
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D012285:Orientia tsutsugamushi / Q000276:immunology; D011933:Reagent Kits, Diagnostic; D012189:Retrospective Studies; D012612:Scrub Typhus / Q000175:diagnosis* / Q000382:microbiology; D012680:Sensitivity and Specificity
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic
keywords: Orientia tsutsugamushi; Rapid Diagnostic Test; Scrub Typhus