title: Development of new, broadly reactive, rapid IgG and IgM lateral flow assays for diagnosis of scrub typhus.
abstract: We evaluated the diagnostic accuracy of two broadly reactive rapid immunochromatographic tests (ICTs) for detection of IgM and IgG against Orientia tsutsugamushi by using archived acute-phase serum samples from 102 patients with laboratory-confirmed scrub typhus, and from 62 archived serum samples from patients with other causes of fever as a negative control. These ICTs were constructed by using a mixture of recombinant proteins: 1) C1, a chimeric protein containing epitopes of the 56-kD antigen from Karp and TA763 strains; 2) Ktr56; and 3) Gmr56. Sensitivities of the ICTs for detection of IgM and IgG were 90.2% (95% confidence interval [CI] = 84.4-96.0%) and 86.3% (95% CI = 80.9-93.8%), respectively. Specificities were 85.5% (95% CI = 73.9-92.2%) and 96.8% (95% CI = 90.3-100%), respectively. Both assays were more sensitive and specific than the standard immune immunofluorescence assay for the early diagnosis of scrub typhus.
authors: Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. aowaluk_8@yahoo.com
authors: Saowaluk
authors: S
authors: Silpasakorn
authors: Nujorn
authors: N
authors: Srisamut
authors: Pattama
authors: P
authors: Ekpo
authors: Zhiwen
authors: Z
authors: Zhang
authors: Chien-Chung
authors: CC
authors: Chao
authors: Wei-Mei
authors: WM
authors: Ching
authors: Yupin
authors: Y
authors: Suputtamongkol
mesh_terms: D001483:Base Sequence; D002846:Chromatography, Affinity; D017931:DNA Primers; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D016133:Polymerase Chain Reaction; D012612:Scrub Typhus / Q000097:blood / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D017931:DNA Primers; D007074:Immunoglobulin G; D007075:Immunoglobulin M