The TB Epidemiological Studies Consortium (TBESC) is a nationwide consortium sponsored by the CDC’s Division of Tuberculosis Elimination (DTBE) and designed to strengthen, focus, and coordinate tuberculosis research. The Consortium is funded through a 10-year CDC contract that was initiated in September 2001 and originally included 19 sites in the U.S. and 2 sites in Canada. Each site is a formal partnership between an academic institution (University of Colorado Health Sciences Center) and a TB control program (Denver Metro TB Clinic). The TBESC designs, conducts, and evaluates programmatically relevant research (epidemiologic, behavioral, economic, laboratory, and operations) concerning the identification, diagnosis, prevention, and control of active TB disease and latent TB infection. Specific multi-site and multi-year research projects are funded by individual task order contracts with consortium members. Project concepts and proposals are developed collaboratively among consortium members, including CDC staff. It is intended that the TBESC will strengthen the scientific underpinnings of future TB control efforts and help the United States achieve the goal of eliminating TB. The Denver Metro TB Clinic is involved with the following Task Orders:
Task Order #6: Regional Capacity-Building in Low-Incidence Areas
This was a 5-year grant (2003-2008) to increase the capacity to identify and treat tuberculosis in 4 low-incidence states: Idaho, Montana, Utah, and Wyoming. The University of California – San Francisco was awarded the contract to work with the sites. The study includes 4 phases:
- Phase 1: Conducting a TB needs assessment in Idaho, Montana, Utah, and Wyoming
- Phase 2: Implementing regionally-based interventions that address priority needs
- Phase 3: Evaluating the interventions
- Phase 4: Developing best practices models
Denver Metro TB Clinic was involved in developing a template for a TB protocol manual for low-incidence states.
Task Order #8: An Analysis of Molecular Epidemiology of MDR-TB in the United States
In 2002, over two-thirds of multi-drug resistant TB (MDR-TB) cases were among foreign-born individuals. The development of MDR-TB can be attributed to programmatic factors such as the lack of DOT, indiscriminate use of anti-TB drugs, and poorly managed TB control programs. Treatment for patients with MDR-TB is difficult and expensive because the patients require prolonged treatment, frequent hospitalizations, and drugs that are less effective and more toxic. This study includes 15 selected TBESC sites which enrolled MDR-TB patients to gain a better understanding of the dynamics of transmission of MDR-TB and to evaluate potential areas for appropriate programmatic interventions.
Methods: Medical and contact investigation records were reviewed for all MDR-TB cases and for those who were identified as having an epidemiological linkage or genotyping match to an MDR-TB case and were resistant to either isoniazid or rifampin. All eligible individuals participated in one interview about an hour in length (interpreters were available for the interview) and their medical records were abstracted. The total duration of the study was 3 years and Denver enrolled 2 patients.
Eligibility Requirements: Any MDR-TB adult or pediatric cases (defined as resistant to at least isoniazid and rifampin) counted and reported as a verified CDC Report of Verified Case of Tuberculosis (RVCT) at the Denver Metro TB Clinic starting in November 2006. Enrollment for this study completed in January 2009.
Task Order #9: Enhanced Surveillance to Identify Missed Opportunities for TB Prevention in Foreign- Born Populations in U.S. and Canada
About 75% of individuals diagnosed with TB at the Denver Metro TB Clinic are foreign-born. Reducing incidence among foreign-born individuals depends on increasing yield from TB control activities. However, these activities need to be tailored to the special circumstances of the foreign-born, including visa status, social and economic hardships, linguistic barriers, and cultural beliefs. This study aimed to provide enhanced surveillance data to identify missed opportunities for preventing TB transmission and disease among foreign-born residents of the U.S. and Canada so that interventions to improve TB control activities are identified.
Methods: Study researchers recruited 1500 foreign-born persons reported with TB in the 22 TBESC sites, including 57 participants from the Denver site. All eligible individuals participated in one interview about an hour in length (interpreters were available for the interview). Enrollment started in April 2005 and was completed in September 2006.
Eligibility Requirements: Eligible individuals were counted and reported as a verified case of TB at the Denver Metro TB Clinic that was a foreign-born adult or pediatric case or any U.S.-born pediatric case (younger than 60 months of age) born to at least one foreign-born parent and any identified source case for a child younger than 60 months of age, regardless of country of birth.
Task Order #13: Prospective Cohort Study of Risk Factors for Acceptance of, Adherence to, and Toxicity from Treatment for LTBI
An estimated 10 to 15 million persons in the U.S. have latent tuberculosis infection (LTBI) and are therefore at risk for progression to active disease. Isoniazid is proven to be an effective medication for treatment of LTBI; however, its effectiveness is limited by low completion rates. For treatment of LTBI to be most effective, barriers to treatment must be better understood as they apply in routine treatment settings. Through a prospective cohort of adults offered LTBI treatment, researchers aim to better understand the scope of treatment in the U.S. and Canada and elucidate factors associated with acceptance and completion of treatment to identify potentially modifiable factors.
Methods: This is a 3-phase study that was initiated in 2003 and data collection was completed in July 2009.
- Phase 1: This phase was completed in 2004. It was a listing and description of clinics in the Denver metro area that provided LTBI treatment.
- Phase 2: This phase was completed in January 2006. It was a retrospective chart review of representative samples of patients who were offered LTBI treatment at the Denver Metro TB Clinic and the Arapahoe County Jail.
- Phase 3: This phase was a prospective cohort of adults 18 years and older who were offered LTBI treatment. Denver enrolled a total of 231 individuals into this study, including both people who accepted and did not accept LTBI treatment. Patients who did not accept LTBI treatment completed one interview about an hour in length. Patients who accepted treatment completed an initial interview, about an hour in length. Treatment acceptors were contacted within 1 month of treatment cessation for an exit interview. Interpreters were available for interviews.
Task Order #18: Evaluation of New Interferon-? Release Assays in the Diagnosis of Latent Tuberculosis Infection in Health Care Workers
This study will evaluate the test characteristics, feasibility, and cost-effectiveness of interferon-? Release assays (IGRAs) and the tuberculin skin test (TST) when testing for LTBI in health care workers (HCWs). HCWs make up a critical study population for IGRAs. According to the U.S. Department of Labor, there are approximately 14 million HCWs in the U.S., most of whom undergo serial skin testing. Testing HCWs is costly and time consuming, but detection of new infection is necessary for discovering TB transmission and for preventing occupation-related TB. The aims of the study include, but are not limited to, comparing the test characteristics (estimated sensitivity and specificity) of two IGRAs (QuantiFERON TB Gold [QFT-G] and T-Spot) to each other and to the TST at initial testing, determining the repeatability and reproducibility of the IGRA results, determining if the TST boosts the IGRA results, and comparing the cost-effectiveness of the three methods.
Methods: This study involves HCWs from Denver Health and Hospital Authority. Participants are administered a questionnaire, have a TST placed and read, and have blood drawn for the IGRAs at baseline and at 6, 12, and 18-months after baseline. Enrollment began in February 2008 and was completed in January 2009.
Task Order #20: Assessing QuantiFERON® as an Initial Screening Tool for U.S.-Bound Applicants for Immigration and Feasibility of Follow-Up in U.S. Immigrants
This study is a collaborate effort between the Centers for Disease Control (CDC), Cho Ray Hospital (CRH) in Ho Chi Minh City, Vietnam, and The Methodist Hospital Research Institute (TMHRI) in Houston, Texas. This is a 3 phase study to look at the feasibility of conducting a larger study to examine the accuracy of the QuantiFERON-TB Gold (QFT) in predicting the future development of active TB among immigrants after arrival in the U.S. Phase 1 will evaluate the potential role of the QFT and/or the tuberculin skin test (TST) in the screening process of immigration applicants. Phase 1 will enroll 1500 individuals, including 100 people with an abnormal chest radiograph (CXR) and 500 with a normal CXR. Phase 2 will follow 120 individuals from Phase 1 to determine the feasibility of following Vietnamese immigrants moving from Vietnam to the U.S. Phase 3 is to determine the feasibility of locating and interviewing individuals who have emigrated from Vietnam and are diagnosed with TB in the U.S. For Phase 3, 25 individuals diagnosed in Colorado and Texas will be enrolled. Enrollment in this study began in December 2008.
Task Order #25: Tuberculosis Mortality in the United States: Epidemiology and Prevention Opportunities
Preventable deaths due to tuberculosis (TB) occur each year in the U.S. and represent a tremendous challenge for TB control programs. While the importance of investigating TB deaths is well recognized, how to collect and use the information to prevent future deaths is not known. In general, cases are considered potentially preventable if there has been a missed opportunity to diagnose and treat latent TB, a delay in diagnosis and treatment of active TB, or both. Task Order #25 is designed to answer many of the current questions surrounding tuberculosis mortality in the U.S. by providing a detailed description of TB deaths in the U.S. between 2005 and 2006. Denver has subcontracted with 2 sites for this task order.
Methods: This study is chart abs