Diagnosis of Extra-Pulmonary Tuberculosis in HIV Patients

DESCRIPTION (provided by applicant): The diagnosis of tuberculosis (TB) in individuals co-infected with human immunodeficiency virus is significantly challenged by the increased prevalence of extra-pulmonary forms of TB in severely immuno- suppressed pati ents. A cost-effective method for the rapid screening of mycobacteria in blood from HIV infected patients is proposed. The technical approach relies on monitoring the metabolic behavior of mycobacteria with exceptional sensitivity and stability using imped ance sensing methods. Corresponding induced metabolic responses allow the rapid detection of viable slow-growing organisms in near-real time. This enables diagnostic results to be obtained without the need for grown cultures reducing the time from sample c ollection to complete diagnosis by many weeks compared to currently used methods. Feasibility of the proposed diagnostic tool will be demonstrated with strains of Mycobacterium smegmatis and Mycobacterium tuberculosis within a 6-month Phase I effor t. A Phase II effort will be focused on the development of a prototype instrumentation and clinical testing with M. tuberculosis samples.Project Narrative A rapid diagnostic test will be developed for detecting the slow-growing bacteria responsible for the disease tuberculosis in severely immunosuppressed individuals co-infected with HIV. The proposed test offers a significant increase in speed over solid media growth and a significant gain in sensitivity over smear microscopy ideal for screening use in developing countries. This enables fewer false negative diagnoses and the positive diagnosis of TB earlier in the disease progression. The impact of this is the improved ability to control the disease and fewer untreated patients returning to the ge neral population to infect others and spread the disease.