1.
In the Diel study “Evidence-based Comparison of Commercial Interferon-gamma Release Assays for Detecting Active Tuberculosis -- a Meta-Analysis,” select the appropriate value for the TSpot cut-off used to be considered for a positive result?
Correct Answer
C. > or equal to 6 spots
Explanation
In the Diel study “Evidence based comparison of commercial interferon-gamma release assays for detecting active tuberculosis -- a meta-analysis,” the TSpot cut-off used to be considered for a positive result is > or = 6 spots.
2.
In the Diel study mentioned above, there were only ___ of the 679 obtained papers met the inclusion criteria for this meta-analysis.
Correct Answer
A. 124 publications
Explanation
In the Deil study, there were only 124 of the 679 obtained papers met the inclusion criteria for this meta-analysis.
3.
Of the 2 U.S. commercially-available IGRAs, which one had a higher pooled sensitivity.
Correct Answer
A. T-Spot
Explanation
Of the 2 commercially-available IGRAs,T-Spot has a higher pooled sensitivity.
4.
In the Diel study “Evidence-based Comparison of Commercial Interferon-gamma Release Assays for Detecting Active Tuberculosis -- a Meta-Analysis,” immuno-compromised patient had fewer in-determinates with T-SPOT.
Correct Answer
A. True
Explanation
In Diel, immuno-compromised patients, TSpot had fewer indeterminates.
5.
According to Diel, which statement is correct?
Correct Answer
D. T-Spot has a higher sensitivity and lower specificity than QFT.
Explanation
T-Spot has a higher sensitivity and lower specificity than QFT.
6.
The Negative Predictive Value (NPV) for the QFT in the Diel study was 98%.
Correct Answer
B. False
Explanation
The Negative Predictive Value (NPV) for the QFT in this Diel study was 100%.
7.
In the Diel study “Negative and Positive Predictive Value of a Whole-Blood Interferon-g Release Assay for Developing Active Tuberculosis,” how many of the TB contacts would the TST at >10mm cutoff were missed in the study that progressed to active TB?
Correct Answer
B. 9 out of 19
Explanation
In the Diel study, 9 out of 19 TB contacts who progressed to active TB with at TST cut-off of 10mm were missed.
8.
CDC recommends either TST or an IGRA for screening immigrant children age ___ from high risk countries.
Correct Answer
A. 2-14 years
Explanation
The CDC recommends either a Tuberculin Skin Test (TST) or an Interferon-Gamma Release Assay (IGRA) for screening immigrant children aged 2-14 years from high-risk countries. This age range is considered to be at higher risk for tuberculosis infection and therefore requires screening to ensure early detection and appropriate treatment if necessary.
9.
In the Diel study “Negative and Positive Predictive Value of a Whole-Blood Interferon Gamma Release Assay for Developing Active Tuberculosis’”, none of the contacts who tested QFT negative developed active TB.
Correct Answer
A. True
Explanation
In the Diel study, none of the contacts who tested QFT negative developed active TB.
10.
Of the available LTBI blood tests, which test demonstrated a better performance trend in BCG-vaccinated children?
Correct Answer
B. QFT
Explanation
Although not statistically significant, QFT demonstrated a better performance trend in BCG-vaccinated children. Note, TST is not a blood test.
11.
In the Garazzino study titled “Performance of interferon-γ Release Assay for the Diagnosis of Active or Latent Tuberculosis in Children in the First 2 Years of Age,” in-determinants results were found to be related to age.
Correct Answer
B. False
Explanation
False.
12.
In the Howley study, “Evaluation of QuantiFERON-TB Gold In-Tube and Tuberculin Skin Tests among Immigrant Children being Screened for Latent Tuberculosis Infection,” which of the following was not one of the 3 countries in which the children were applying for immigration status from in this study.
Correct Answer
B. Africa
Explanation
In the Howley study, “Evaluation of QuantiFERON-TB Gold In-Tube and Tuberculin Skin Tests among Immigrant Children being Screened for Latent Tuberculosis Infection,” children from Mexico, Philippines and Vietnam were the 3 countries in which the children were applying for immigration status.
• Mexico
• Philippines
• Vietnam
13.
In Starke’s article “Interferon-γ Release Assays for Diagnosis of Tuberculosis Infection and Disease in Children,” about 50% infants who received a BCG-vaccine will respond with a significant induration to a TST.
Correct Answer
A. True
Explanation
The statement is true because in Starke's article, it is mentioned that approximately 50% of infants who received a BCG vaccine will have a significant induration (hardened bump) in response to a Tuberculin Skin Test (TST). This means that the BCG vaccine can cause a reaction that mimics a positive result for tuberculosis infection in the TST.
14.
IGRAs are the "Gold Standard" for active TB testing.
Correct Answer
B. False
Explanation
There is no "Gold Standard" assay for active TB testing. IGRAs test for latent TB not active.
15.
More positives and fewer in-determinants results were noted by which assay in the Cheallaigh “Interferon Gamma Release Assays for the Diagnosis of Latent TB Infection in HIV Infected Individuals in a Low TB Burden Country" study?
Correct Answer
C. QFT-IT
Explanation
In low TB prevalence settings, the QFT-IT yields more positive and fewer indeterminate results
than T-SPOT.TB. Negative results on the QFT-IT and indeterminate/unavailable results on the T-SPOT.TB were more common in individuals with low CD4+ T-cell counts.
16.
It was suggested in the Diel study “Negative and Positive Predictive Value of a Whole-Blood Interferon-g Release Assay for Developing Active Tuberculosis’” that QFT is more reliable than the TST for identifying those who will soon progress to active TB, especially in children.
Correct Answer
A. True
Explanation
Results suggest that QFT is more reliable than the TST for identifying those who will soon progress to active TB, especially in children.
17.
In Long, “Interferon-Release Assay for the Diagnosis of Latent Mycobacterium tuberculosis Infection in Children Younger Than 5 Years: A Meta-Analysis,” showed that the sensitivity and specificity of ______ were slightly higher than ___ and can be used as supporting tools to detect LTBI in children younger than 5 years.
Correct Answer
C. IGRAs and TST
Explanation
In Long, “Interferon-Release Assay for the Diagnosis of Latent Mycobacterium tuberculosis Infection in Children Younger Than 5 Years: A Meta-Analysis,” showed that the sensitivity and specificity of IGRAs were slightly higher than TST and can be used as supporting tools to detect LTBI in children younger than 5 years.
18.
Which diagnostic assay has the least amount of subjectivity in diagnosing latent TB infection?
Correct Answer
A. QFT-TB Gold
Explanation
QuantiFERON-TB Gold has proven to have less subjectivity in diagnosing LTBI.
19.
False-negative TST results can occur when children suffer from severe active TB or immune suppression.
Correct Answer
A. True
Explanation
In Long, “Interferon-Release Assay for the Diagnosis of Latent Mycobacterium tuberculosis Infection in Children Younger Than 5 Years: A Meta-Analysis,” False-negative TST results can occur when children suffer from severe active TB or immune suppression.
20.
Cheallaigh, “Interferon Gamma Release Assays for the Diagnosis of Latent TB Infection inHIV-Infected Individuals in a Low TB Burden Country,” states tuberculosis is the most common opportunistic infection in HIV-infected individuals and is responsible for how many of HIV associated deaths?
Correct Answer
C. 1/3
Explanation
In the Cheallaigh study, “Interferon Gamma Release Assays for the Diagnosis of Latent TB Infection in
HIV-Infected Individuals in a Low TB Burden Country,” states tuberculosis is the most common opportunistic infection in HIV-infected individuals and is responsible for one-third of HIV associated deaths.