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:2/13/2016)... ... February 13, 2016 , ... In the early or “honeymoon” stage of a ... go out of their way to be romantic, and may exaggerate a strength or ... any online dating profile. , A recent study from Queendom.com , however, ...
(Date:2/12/2016)... ... February 12, 2016 , ... ... a new initiative—the Siemens Foundation-PATH Ingenuity Fellowships—to develop the advanced skills needed ... top students from U.S. universities who will draw from Siemens’ deep knowledge ...
(Date:2/12/2016)... (PRWEB) , ... February 12, 2016 , ... As a ... hectic schedule, a demanding job, and no time to decompress, Rabinowitz found herself drawn ... herself to meditation for its impact on her life, implementing a 20-minute-per-day meditation practice ...
(Date:2/12/2016)... ... February 12, 2016 , ... Every winter, someone is killed, injured ... West Penn Burn Center, part of the Allegheny Health Network, has partnered ... you the “Space Heaters Need Space” campaign. , “Space Heaters Need Space” ...
(Date:2/12/2016)... ... 12, 2016 , ... Erlanger Agency has announced a new partnership in its ... campaign focuses on the fight against breast cancer, fundraising for a local woman named ... . , Carmen is a loving single mother of two boys who also serves ...
Breaking Medicine News(10 mins):
(Date:2/12/2016)... MONTREAL , February 12, 2016 ... sofern nicht anders vermerkt)   ... Unternehmens http://www.telestatherapeutics.com abrufbar.    ... Website des Unternehmens http://www.telestatherapeutics.com ... Inc. (TSX:TST; PNK:BNHLF) veröffentlichte heute seinen Konzernabschluss ...
(Date:2/12/2016)... 12, 2016  SI-BONE, Inc., a medical device company that pioneered ... minimally invasive surgical (MIS) device indicated for fusion for certain disorders ... (NGS), the Medicare Administrative Contractor (MAC) covering the states of ... Maine , Massachusetts , Minnesota ... York , Rhode Island , ...
(Date:2/12/2016)... , Feb. 12, 2016  Memorial Hermann Health System ... Dwight Howard to bring a one-of-a-kind experience to ... Using cutting-edge technologies such as 360-degree video and Google ... virtually, then literally – giving the patients and their ... it was all caught on video . ...
Breaking Medicine Technology: