Screening of latent infection by Mycobacterium tuberculosis (LTBI) and treatment of positive subjects is the key point in the prevention of TB; such a strategy should be performed mainly among individuals with risk of progression. Progression from LTBI to active TB is highest both in recent contacts of patients with active TB, and in immunocompromised subjects. Therefore, LTBI could either be c...

To the Editor: In their review article, Getahun et al. (May 28 issue)1 provide a useful overview of issues surrounding latent tuberculosis infection. However, newly published data regarding the performance of the T-SPOT.TB assay call into question the supposition that false conversions and reversions are more common with interferon-γ release assays (IGRAs) than with tuberculin skin tests.2 Spec...

The tuberculin skin test (TST) has many limitations for the diagnosis of latent tuberculosis (TB infection. The aim of this study in Egypt was to estimate the usefulness of an interferon-gamma release assay (IFN-gamma) assay for the detection of latent TB infection in contacts of active TB cases. A total of 116 participants were enrolled and divided into 3 groups: community controls, casual (la...

BACKGROUND We determined the consistency of positive interferon-gamma (IFN-γ) release assays (IGRAs) to detect latent TB infection (LTBI) over one-year postpartum in HIV-1-infected women. METHODS Women with positive IGRAs during pregnancy had four 3-monthly postpartum IGRAs. Postpartum change in magnitude of IFN-γ response was determined using linear mixed models. RESULTS Among 18 women wit...

BACKGROUND Currently available Interferon-gamma release assays (IGRAs) show a considerable variability in serial testing for latent tuberculosis infection (LTBI). This study offers first results for the new generation IGRA QuantiFERON-TB Gold Plus (QFT-Plus) introduced in 2015 in comparison with its predecessor QuantiFERON-TB Gold In-Tube (QFT-GIT) from serial testing of students with a migrati...

The Centers for Disease Control and Prevention recently published updated guidelines for the use of interferon gamma release assays (IGRAs) to detect Mycobacterium tuberculosis. This document gives a balanced analysis of the strengths and weaknesses of IGRAs. To date, these assays have not been widely adopted in the United States by clinical laboratories. We have asked two experts, Thomas Alexa...

BACKGROUND Although North American hospitals are switching from tuberculin testing (TST) to interferon-gamma release assays (IGRAs), data are limited on the association between occupational exposure and serial QuantiFERON-TB Gold In-Tube (QFT) results in healthcare workers (HCWs). METHODS In a cohort of Canadian HCWs, TST and QFT were performed at study enrolment (TST1 and QFT1) and 1 year la...

Objective Two interferon-gamma release assays (IGRAs), the QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB (T-SPOT), are commercially available. The agreement between the two IGRAs in the screening of healthcare workers (HCWs) for latent tuberculosis is not well known. Methods The QFT-GIT and T-SPOT tests were performed for the baseline tuberculosis screening of 654 HCWs who worked at Mie U...

BACKGROUND Healthcare workers (HCW) are a risk group for tuberculosis (TB). That is why interferon-gamma release assay (IGRA) serial testing is performed on HCWs repeatedly exposed to infectious patients or materials. However, the variability of IGRA in serial testing is not yet well understood. We therefore analysed the prevalence of positive IGRA results as well as conversion and reversion ra...

Tuberculosis (TB) cellular immune responses were examined in the breast milk of human immunodeficiency virus infected mothers using the T-SPOT. TB interferon-gamma release assay (IGRA). Positive TB interferon-gamma (IFN-γ) responses were detected in 6 of 8 (75%) valid breast milk assays. Among 7 mothers with paired breast milk and blood assays, TB IFN-γ responses were higher in breast milk than...