Clinical ,Laboratory analysis and comparative evaluation of serological tests for diagnosis of scrub typhus disease in Madhya Pradesh, India.

Abstract

Background : Scrub typhus is difficult to distinguish from other acute febrile illnesses because of its non-specific clinical signs and the Indian population's comparatively low eschar rate. Thus, laboratory tests are the main method of diagnosis. The majority of scrub typhus diagnosis made by antibody-based serological testing. Here, we assessed the efficacy of IgM ELISA,ICT and Weil Felix as diagnostic tools for identifying O. tsutsugamushi antibodies in patients' acute serum.

Methodology: The study included 524 random patients with acute undifferentiated febrile illness (AUFI).Patients age from 3 to 75 years included.IgM ELISA, Weil Felix test, and rapid immunochromatography(ICT) serological diagnostic techniques used to identify scrub typhus cases. Clinical characteristics, medical laboratory parameters, and final results analyzed.

Results: We observed that for the diagnosis of scrub typhus, IgM ELISA with a cutoff titer of 0.5 OD has excellent diagnostic accuracy (sensitivity of 99.9% and specificity of 99.1%). The ICT utilized in this investigation exhibited a high specificity of 94.19% and sensitivity of 94.87%,with acute serum samples. As a screening or point-of-care test, ICT must be more sensitive, but it may afford to make certain compromises in terms of specificity. The ideal threshold for ICT should  be assessed in various contexts.

Conclusion: The implication and importance of Rapid Immunochromatography Test (ICT) play crucial role for the diagnosis of scrub typhus. ICT provides rapid diagnostic point –of-care test (POCT). Rapid immunochromatographic test simple and trendy because of quick result, less requirements, less espertise and easy to perform in remote and rural areas.