Saowaluk SilpasakornNujorn SrisamutPattama EkpoZhiwen ZhangChien Chung ChaoWei Mei ChingYupin SuputtamongkolMahidol UniversityNaval Medical Research CenterFaculty of Medicine, Siriraj Hospital, Mahidol University2018-06-112018-06-112012-07-01American Journal of Tropical Medicine and Hygiene. Vol.87, No.1 (2012), 148-152000296372-s2.0-84863741229https://repository.li.mahidol.ac.th/handle/20.500.14594/14298We 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. Copyright © 2012 by The American Society of Tropical Medicine and Hygiene.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.4269/ajtmh.2012.11-0583