TB Notes Newsletter
No. 3, 2012
TB EPIDEMIOLOGIC STUDIES CONSORTIUM II (TBESC) UPDATES
TBESC Session at the 2012 ATS International Conference
Current and future Tuberculosis Epidemiologic Studies Consortium-II (TBESC) and Tuberculosis Trials Consortium (TBTC) research studies were the focus of a session at the 2012 American Thoracic Society International Conference in San Francisco. The purpose of this session, held on May 20, 2012, was to present data on recent studies performed by the consortia, and describe future plans for both research consortia.
Denise Garrett, MD, provided a description of new TBESC research. In order to achieve TB elimination in the United States, she told session participants, it is necessary to identify and treat persons with latent TB infection (LTBI) who are at high risk for progression to TB disease. Therefore, the main study of the new TBESC will compare tuberculin skin test (TST), T-SPOT.TB, and QuantiFERON-Gold In-Tube to determine the best test for diagnosing LTBI and predicting progression to TB disease. The study will take place at 15 clinics in 11 states, and will enroll 48,000 persons over 8 years who are at high risk for LTBI or progression to TB. Persons diagnosed with LTBI will be treated as clinically indicated, and all study enrollees will be followed for development of TB. Additional sub-studies will be performed during the lifetime of the consortium, and may include testing of shorter LTBI treatment regimens, and evaluation of measures to enhance adherence to LTBI treatment.
Dr. Dylan Shepardson of the TBTC discussed, “Can a shorter treatment regimen be a better use of resources for preventing tuberculosis?” By creating a model to evaluate health outcomes, health system costs, and patient costs when using 3 months of isoniazid and rifapentine (3HP) compared to 9 months of isoniazid (9H), he found that the use of 3HP prevented 5.2 TB cases per 1,000 persons treated, and saved 24 more quality-adjusted life years (QALYs) per 1,000 persons treated. However, 3HP costs more than 9H from both a health system and patient perspective. When health system costs are considered, 3HP costs $112 more per person. When patient costs are taken into account, 3HP costs only $22 more per person. The sensitivity analysis indicated that increased costs of directly observed therapy (DOT) and higher rifapentine costs favored the use of 9H. However, higher risk of progression to disease and greater value placed on patient time favored the use of 3HP. He stated that their future work includes creating an online model that would allow health departments to enter data pertinent to their site in order to identify the most cost-effective regimen.
Dr. Payam Nahid, a TBTC site PI and Chair of the TBTC Biomarker Working Group, spoke about “GeneXpert and TBTC: Expected benefits and innovative uses.” He noted that GeneXpert has the potential to increase the patient pool available for TBTC clinical trials given the MTB/RIF assay’s high sensitivity and specificity for detection of M. tuberculosis as compared to sputum smear microscopy. As such, smear-negative pulmonary TB patients can be potential candidates for clinical trials. Further, patients with AFB-positive sputa due to suspected nontuberculous mycobacteria can also be more efficiently excluded from trial participation and referred for additional work-up and appropriate management. The assay’s rapid detection of rifampin resistance improves efficiency around screening procedures at two points. It does so at baseline for multidrug-resistant (MDR) TB and drug-susceptible TB trials, and also during follow-up, to detect acquired rifampin resistance in clinical trial patients with treatment failure or recurrence. However, challenges to be overcome include the need for INH monoresistance testing in clinical trials, the need to rule out extensively drug-resistant (XDR)-TB in patients with isolates shown to have rifampin resistance by the assay, and the fact that a positive result in GeneXpert doesn’t imply that the TB pathogen is viable. He stated that additional innovations are needed before the full capabilities for use in clinical trials are realized.
The TBESC/TBTC session was very well-attended. The audience asked a variety of questions demonstrating their interest in present and future TB research being performed by the consortia. These presentations were useful in providing an overview of some of the important research being done in LTBI and TB diagnosis and prevention, both domestically and internationally.
—Reported by Suzanne Beavers, MD
Div of Environmental Hazards and Health Effects
National Center for Environmental Health
(formerly Div of TB Elimination)
Contact Us:
- Centers for Disease Control and Prevention
Division of Tuberculosis Elimination (DTBE)
1600 Clifton Rd., NE
MS E10
Atlanta, GA 30333 - 800-CDC-INFO
(800-232-4636)
TTY: (888) 232-6348 - New Hours of Operation
8am-8pm ET/Monday-Friday
Closed Holidays - cdcinfo@cdc.gov
