Supersensitive detection of scrub typhus

The detection of diseases induced by rickettsia is difficult. PCR has been used, but the sensitivity is often far from perfect. Serologic tests are based mostly on host antibodies, i.e. they use late biomarkers because antibodies against O.tsutsugamushi usually appear only after about 10-14 days. Antigens, i.e. bacterial proteins are present much earlier but a very sensitive immunoassay is necessary to detect them. MPD enhanced immunoassays (IA/MPD) may provide early detection of O.tsutsugamushi.MPD methods are applicable to the full spectrum of microbials, including viruses and bacteria. In this proposal, we describe a new, more sensitive immunoassay for O. tsutsugamushi, the etiologic agent of scrub typhus. We propose the use of supersensitiveMPD enhanced immunoassays (IA/MPD) targeting a well known antigen. Initially, we will develop a microtiter based method with a sensitivity expected to be about a hundred-fold higher than the ELISA currently being used. In Phase II we will develop aportable implementation based on the lateral flow immunoassay concept. A portable MPD detector will be implemented. This supersensitive, reliable and user friendly system presents the most sensitive and pragmatic solution for the detection of scrubtyphus. The applications of MPD enhanced methods for the detection of bacterial pathogens is a very large field with a total market of about 1 billion dollars/year. A considerable fraction of this market is the detection of tropical diseases, including scrubtyphus. Because of the need for early detection and immediate treatment, super-sensitive tests are required. User friendliness and analytical reliability (a low number of false positives and negatives) are essential as well. In scrub-typhus detection, atrained soldier must be able to use the supersensitive test and then properly interpret the measured result. Due to its technical advantages, the MPD enhanced detection modalities have a chance to dominate this market. Ultra-high sensitivity, userfriendliness, an optimum number of tests for adequate detection and response, as well as the low cost per assay are crucial. Due to its sensitivity advantages, MPD enhanced detection modalities have a chance to dominate this market.