Tuberculosis screening on a health science campus: use of QuantiFERON-TB Gold Test for students and employees

The effectiveness of screening with interferon-gamma release assays in a university health care setting with a diverse global population

OBJECTIVE

This analysis examined the effectiveness of utilizing interferon-gamma release assay (IGRA) technology in a TB (TB) screening program at a university.

PARTICIPANTS

Participants were 2299 students at a Montana university who had presented to the university health center for TB screening during 2012 and 2013.

METHODS

A retrospective study was conducted utilizing data from student health center medical records. Time and financial expenditures were determined, and the cost of the present screening process and 2 alternative scenarios was calculated.

RESULTS

The current process is the most costly and time-consuming scenario for TB testing. Testing exclusively with IGRAs is the least labor-intensive for staff and creates revenue, whereas a dual method, utilizing IGRAs for high-risk students and skin tests for others, provides a solution that better responds to the demographic of the population.

CONCLUSIONS

This assessment shows that IGRAs are a cost-effective tool for screening a global student population.

Tuberculin skin test conversion among health sciences students: a retrospective cohort study

Previous studies have reported that health sciences students are at greater risk for tuberculosis infection, especially in developing countries. The objective of this study was to estimate the prevalence, incidence, and factors associated with latent tuberculosis infection among Health Sciences students in Peru. Students enrolled at private university (in Lima-Peru) are tested annually for tuberculosis infection by tuberculin skin test. Data on tuberculin skin test results between 2002 and 2009 was used in this retrospective cohort study, a total of 4842 students were included. Tuberculin skin test conversion was defined as the change of tuberculin skin test from negative (<10 mm) to positive (≥10 mm) after 48-72 h of inoculation. Baseline tuberculin skin test positivity was 1.0% (95%CI: 0.6%-1.3%), whereas tuberculin skin test conversion incidence was 12.4 per 100 person-years (95%CI: 11.8-13.0). This study showed that students from clinical careers in close contact with patients had an increased risk of tuberculosis infection in the internship, especially Medicine, Dentistry, Medical Technology and Nursing. Administrative, environmental and personal protection measures should be implemented and evaluated periodically in order to reduce the risk of exposure.

Specificity of the tuberculin skin test and the T-SPOT.TB assay among students in a low-tuberculosis incidence setting

OBJECTIVE

Interferon-γ release assays (IGRAs) are an important tool for detecting latent Mycobacterium tuberculosis infection (LTBI). Insufficient data exist about IGRA specificity in college health centers, most of which screen students for LTBI using the tuberculin skin test (TST).

PARTICIPANTS

Students at a low-TB incidence college health center.

METHODS

TST and T-SPOT.TB were performed on prospectively recruited students. TB exposure risk was assessed using a questionnaire: Those at low risk were assumed to not have LTBI in order to calculate test specificity.

RESULTS

Of 184 students enrolled, 143 had results available for both TST and T-SPOT.TB. Agreement of the tests was 97% (kappa statistic 0.717; 95% confidence interval, 0.399-1.00). Among 124 low-risk students, specificity for TST and T-SPOT.TB were 98.4% and 100%, respectively.

CONCLUSIONS

T-SPOT.TB specificity was high among low-risk students. Additional studies such as cost-effectiveness analyses using T-SPOT.TB as a single or confirmatory test to TST are needed to contribute to LTBI screening policy decisions.

Utilization of the QuantiFERON-TB Gold test in a two-step process with the tuberculin skin test to evaluate health care workers for latent tuberculosis

A cost analysis of combining a tuberculin skin test (TST) and the QuantiFERON-TB Gold test (QFT-GT) to detect latent tuberculosis in newly hired health care workers was performed. An approximately 50% reduction in the cost of additional care was realized when workers with positive TST results were subsequently screened using the QFT-GT.