Rapid Serological Diagnosis of Scrub Typhus Infections

Infectious disease is a serious threat to military personnel in operations in third world countries. The ability to rapidly diagnose disease is critical to initiate treatment and to reduce troop mortality. This research addresses the DoD need to adaptstate-of-the-art technology to develop a rapid, field-usable assay capable of diagnosing scrub typhus infection. ChelaTech has developed new composite materials for protein chromatography, that decrease the time necessary to perform immunoassays by anorder of magnitude, while increasing selectivity and sensitivity. The assay device is a transparent plastic tube with a thin layer of nonporous silica beads packed into it. The interstitial spaces between the beads are crossed with a thin hydrophilicpolymer matrix, that is covalently grafted to the support and immobilizes a typhus antigen. This Phase I Research will use this technology to develop an immunoassay for typhus antigen-binding IgG and IgM. Briefly, a patients' serum is complexed withProtein A-colloidal gold, and passed into the interstitial antigen column. The immunoglobulins against typhus antigen are bound in the tube and visualized. Non-binding proteins and colloidal gold are rinsed out. The unprecedented adsorption kinetics ofthe interstitial column permit the immunoassay to be completed within a few seconds. The commercial applications of this Research will be the development of ultra-fast immunoassays for clinical diagnosis and laboratory measurements. The interstitialchromatography composites developed by ChelaTech enable separation and accurate analysis of proteins within a few seconds. This technology will be used in this research to develop convenient immunoassays for infectious diseases, that can be performed in aminute. This order of magnitude increase in assay speed will have a substantial impact on the clinical diagnostics industry.