Rapid Serological Diagnosis of Scrub Typhus Infections

Scrub typhus, caused by Orientia tsutsugamushi poses a threat to U.S. forces deployed to the Asian/Australian/Pacific regions during contingency and peacekeeping operations. Development of an assay for the detection of O. tsutsugamushi that is rapid, accurate, field-usable and soldier-friendly is therefore a high priority for the DoD. In its Phase I effort, Access Bio demonstrated the feasibility in development of a prototype assay to detect scrub typhus employing immunochromatographic assay technology. The developed test system is field-deployable (blood assay, hand-held device, ten minutes assay, no equipment, no special facility, field storage, field-temperature operation), soldier-friendly (easy-to-operate, no special training), accurate and clinically useful (separate result for IgM and total antibodies, 100% agreement with the clinical samples). In Phase II research and development, Access Bio will further develop and deliver the test system for the confirmation of the project goal. This test system will be able to distinguish between the acute infection and chronic infection of scrub typhus. Four subsequent lots of the assay will be produced and delivered for evaluation by the COR. The same technology which showed satisfactory feasibility in Phase I will be employed. Target sensitivity and specificity is >95%.