|
|
|
|||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||
TB Notes NewsletterReturn to TB Notes 3, 2006 Main Menu This is an archived document. The links and content are no longer being updated. No. 3, 2006TUBERCULOSIS EPIDEMIOLOGIC STUDIES CONSORTIUMNew TBESC Study to Be Launched: Evaluation of New Interferon-gamma Release Assays in the Diagnosis of Latent TB Infection in Health Care WorkersPrincipal Investigator: Chuck Daley Co-Principal Investigators: Nick Deluca, Jerry Mazurek, Susan Dorman The TBESC is planning a new study titled “Evaluation of New Interferon-gamma Release Assays in the Diagnosis of Latent Tuberculosis Infection in Health Care Workers.” The study will evaluate the test characteristics, feasibility, and cost-effectiveness of interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST) when testing for LTBI in health care workers (HCWs) at 4 to 6 TBESC sites. HCWs make up a critical study population for IGRAs. According to the Labor Department, there are approximately 14 million HCWs in the United States, most of whom undergo serial skin testing. HCWs represent a diverse yet stable and accessible population with a wide range of rates of LTBI and risks of TB exposure. Testing them is costly and time consuming, but detection of new infection is necessary for discovering M. tuberculosis transmission and for preventing occupation-related TB. The consequences of missing TB in a HCW are potentially disastrous (CDC. MMWR 2004: MMWR 2005). Until recently the only method for detecting infection was the TST, which requires two-step testing for the initial evaluation. The TST has a number of important deficiencies: it lacks sensitivity and specificity, its results are influenced by BCG vaccination, and it requires two health care visits to obtain results. IGRAs have excellent sensitivity and specificity and provide some advantages over the TST. IGRAs require one health care visit, the result can be available within one day, and interpreting the test results is less subjective than for the TST. Many HCWs in the United States were born in countries where the incidence of TB is high and where BCG vaccination is routine. IGRAs using region-of-difference 1 antigens are not influenced by BCG vaccination, which may increase HCW confidence in the result. IGRAs must be evaluated longitudinally in HCWs to determine the frequency of reversion and conversion, to determine the optimal definition of conversion, and to study the repeatability and reproducibility of these new tests. Because a switch from skin testing to IGRAs will represent a major change in our approach to testing HCWs, it is important to assess the utilization and acceptability of these new tests among patients and providers. Given the large number of HCWs in the United States, it is important to evaluate the cost-effectiveness of the different testing methods in health care settings. The specific aims of the study are as follows:
Submitted by Chuck Daley and Rachel Albalak TBESC
Last Reviewed: 05/18/2008 |
|
|
If you would like to order any of the DTBE publications please visit the online order form. You will need Adobe Acrobat™ Reader v5.0 or higher to read pages that are in PDF format. Download the Adobe Acrobat™ Reader. If you have difficulty accessing any material on the DTBE Web site because of a disability, please contact us in writing or via telephone and we will work with you to make the information available. Division of Tuberculosis Elimination
Centers for Disease Control & Prevention |