Navigation Links
Discordance among commercially-available diagnostics for latent TB infection
Date:12/8/2011

In populations with a low prevalence of tuberculosis (TB), the majority of positives with the three tests commercially available in the U.S for the diagnosis of TB are false positives, according to a new study.

"We compared commercially available tests for latent tuberculosis infection (LTBI) in a diverse population with a low LTBI prevalence," said James Mancuso, MD, DrPH, of the Walter Reed Army Institute of Research Preventive Medicine Residency Program. "Our results suggest that in low-prevalence populations, most positive results obtained with these tests are false positives."

The findings were published online ahead of print publication in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.

The cross-sectional study involved 2,017 military recruits at Fort Jackson, South Carolina, who completed a risk factor questionnaire and underwent testing with the 3 tests: 1) tuberculin skin test (TST), 2) the interferon gamma release assays (IGRAs) QuantiFERON-TB Gold In-Tube test (QFT-GIT) and 3) the TSPOT TB test (T-Spot). The Battey Skin Test (BST) was also administered to assess the impact of non-tuberculosis mycobacteria (NTM) reactivity on test discordance.

The specificities of TST, QFT-GIT, and T-Spot were not significantly different. Of 88 subjects with a positive test, 68 (77%) were positive to one test, 10 (11.4%) were positive to two tests, and only 10 (11.4%) were positive to all three tests. Bacille Calmette Guerin vaccination, tuberculosis prevalence in country of birth,and Battey skin test reaction size were associated with TST positive, IGRA negative test discordance, supporting evidence that NTM sensitization can cause false positive TST results. Greater quantitative test results and higher TB risk strata were associated with increased concordance between tests.

"Our data support a high proportion of false positives with any of these three tests in a low- prevalence population," added Dr. Mancuso, "as 77 percent of our subjects had positive results with only one test. Lower quantitative results were associated with a smaller risk for TB exposure and single positive tests, and lower risk for TB exposure was associated with decreasing test agreement."

There were some limitations to the study, including the lack of a gold standard for determining the presence of M. tuberculosis infection and administrative restrictions that resulted in an increased proportion of inadequate blood draws and TST reading times, which were slightly shorter than optimal.

"Low positive predictive value (PPV) is a well-known issue with the TST, and risk stratification is recommended to guide interpretation of the test," concluded Dr. Mancuso. "Our study suggests that risk stratification may also increase the PPV and reduce the number of false positives with the IGRAs. In accordance with the CDC's recommendation, people at minimal risk of TB infection should not be targeted for LTBI testing, regardless of which test is used."


'/>"/>
Contact: Nathaniel Dunford
ndunford@thoracic.org
212-315-8620
American Thoracic Society
Source:Eurekalert

Related medicine news :

1. Stress reduction and mindful eating curb weight gain among overweight women
2. Genes modify the risk of liver disease among alcoholics
3. Health gap has grown among young US adults, study finds
4. Study finds inadequate mask use among health care workers early in 2009 H1N1 outbreak
5. Health-care providers should be alert to risk of suicide among pregnant women and new mothers
6. Study finds sex a significant predictor of happiness among married seniors
7. Malpractice suits cause psychological distress and career burnout among US surgeons
8. New University of Houston research addresses problem drinking among college students
9. NIH scientists discover link among spectrum of childhood diseases
10. Stomach Bug Easily Passed Among Pro Sports Teams: Report
11. Stress Linked to Higher Mortality Risk Among Men
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/26/2016)... ... June 26, 2016 , ... Many women are ... with endometriosis. These women need a treatment plan to not only alleviate symptoms ... can help for preservation of fertility and ultimately achieving a pregnancy. The specialists ...
(Date:6/25/2016)... ... June 25, 2016 , ... First Choice Emergency Room , the ... Ogunleye, as the Medical Director of its new Mesquite-Samuell Farm facility. , “We ... new Mesquite location,” said Dr. James M. Muzzarelli, Executive Medical Director of First Choice ...
(Date:6/24/2016)... Los Angeles, CA (PRWEB) , ... June 24, 2016 , ... ... plastic surgery procedures that most people are unfamiliar with. The article goes on to ... known procedures, but also many of these less common operations such as calf and ...
(Date:6/24/2016)... ... ... Global law firm Greenberg Traurig, P.A. announced that 20 Florida attorneys are ... for this recognition are considered among the top 2 percent of lawyers practicing within ... of this year’s Legal Elite Hall of Fame: Miami Shareholders Mark D. Bloom, ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... ... today at the Clinical Decision Making in Emergency Medicine conference in Ponte Vedra ... authored journal articles published in Emergency Medicine Practice and Pediatric Emergency ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... Story Highlights: ... the health care industry is causing providers to review ... Deloitte offers a suite of solutions for health care ... cost optimization: labor resource analysis, revenue cycle optimization and ... outcomes and better economics ...
(Date:6/24/2016)... June 24, 2016 ... announced the addition of the " Global Markets ... This report focuses ... an updated review, including its applications in various applications. ... market, which includes three main industries: pharmaceutical and biotechnology, ...
(Date:6/24/2016)... -- Research and Markets has announced the addition ... report to their offering. ... The World Market for Companion Diagnostics covers the world ... in the report includes the following: , ... by Region (N. America, EU, ROW), 2015-2020 , World ...
Breaking Medicine Technology: