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Use of a T Cell Interferon-γ Release Assay to Evaluate Tuberculosis Risk in Newly Qualified Physicians in Singapore Healthcare Institutions

Published online by Cambridge University Press:  02 January 2015

C. B. E. Chee ,
L. K. Y. Lim ,
T. M. Barkham ,
D. R. Koh ,
S. O. Lam ,
L. Shen  and
Y. T. Wang
C. B. E. Chee*
Affiliation:
Tuberculosis Control Unit, Tan Tock Seng Hospital, Singapore
L. K. Y. Lim
Affiliation:
Tuberculosis Control Unit, Tan Tock Seng Hospital, Singapore
T. M. Barkham
Affiliation:
Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore
D. R. Koh
Affiliation:
Yong Loo Lin School of Medicine, National University of Singapore, Singapore
S. O. Lam
Affiliation:
Tuberculosis Control Unit, Tan Tock Seng Hospital, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore
Y. T. Wang
Affiliation:
Tuberculosis Control Unit, Tan Tock Seng Hospital, Singapore
*
Control Unit, 144 Moulmein Road, Singapore30809 (cynthia_chee@ttsh.com.sg)
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Abstract

Background.

Surveillance for latent tuberculosis in high-risk groups such as healthcare workers is limited by the nonspecificity of the tuberculin skin test (TST) in BCG-vaccinated individuals. The Mycobacterium tuberculosis antigen-specific interferon-γ release assays (IGRAs) show promise for more accurate latent tuberculosis detection in such groups.

Objective.

To compare the utility of an IGRA, the T-SPOT.TB assay, with that of the TST in healthcare workers with a high rate of BCG vaccination.

Methods.

Two hundred seven medical students from 2 consecutive cohorts underwent the T-SPOT.TB test and the TST in their final year of study. Subjects with negative baseline test results underwent repeat testing after working for 1 year as junior physicians in Singapore's public hospitals.

Results.

The baseline TST result was an induration 10 mm or greater in diameter in 177 of the 205 students who returned to have their TST results evaluated (86.3%), while the baseline T-SPOT.TB assay result was positive in 9 (4.3%) of the students. Repeat T-SPOT.TB testing in 182 baseline-negative subjects showed conversion in 9 (4.9%). A repeat TST in 18 subjects with baseline-negative TST results did not reveal any TST result conversion.

Conclusions.

The high rate of positive baseline TST results in our BCG-vaccinated healthcare workers renders the TST unsuitable as a surveillance tool in this tuberculosis risk group. Use of an IGRA has enabled the detection and treatment of latent tuberculosis in this group. Our T-SPOT.TB conversion rate highlights the need for greater tuberculosis awareness and improved infection control practices in our healthcare institutions.

Type
Original Articles
Information
Infection Control & Hospital Epidemiology , Volume 30 , Issue 9 , September 2009 , pp. 870 - 875
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2009

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References

1.Menzies, D, Fanning, A, Yuan, L, Fitzgerald, M. Tuberculosis among health care workers. N Engl J Med 1995;332:92–98.CrossRefGoogle ScholarPubMed
2.Sterling, TR, Haas, DW. Transmission of Mycobacterium tuberculosis from health care workers. N Engl J Med 2006;355:118–121.CrossRefGoogle ScholarPubMed
3.Mycobacterium tuberculosis transmission in a newborn nursery and maternity ward—New York City, 2003. MMWR Morb Mortal Wkly Rep 2005;54:1280–1283.Google Scholar
4.Jensen, PA, Lambert, LA, Iademarco, M, Ridzon, R. Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care settings, 2005. MMWR CDC Surveill Summ 2005;54(RR17):1T141.Google ScholarPubMed
5.American Thoracic Society. Targeted tuberculin testing and treatment of latent tuberculosis infection. Am J Respir Crit Care Med 2000;161(Suppl 4):S221–S247.CrossRefGoogle Scholar
6.Baussano, I, Bugiani, M, Carosso, A, et al.Risk of tuberculin conversion among healthcare workers and the adoption of preventive measures. Occup Environ Med 2007;64:161–166.CrossRefGoogle ScholarPubMed
7.Louther, J, Rivera, P, Feldman, J, Villa, N, DeHovitz, J, Sepkowitz, KA. Risk of tuberculin conversion according to occupation among health care workers at a New York City hospital. Am J Respir Crit Care Med 1997;156:201–205.CrossRefGoogle Scholar
8.Menzies, RI. Tuberculin skin testing. In: Reichman, LB, Hershfield, ES, eds. Tuberculosis: A Comprehensive International Approach. New York, NY: Marcel Dekker; 2000:279–322.Google Scholar
9.Menzies, D, Pai, M, Comstock, G. Meta-analysis: new tests for the diagnosis of latent tuberculosis infection—areas of uncertainty and recommendations for research. Ann Intern Med 2007;146:340–354.CrossRefGoogle ScholarPubMed
10.Lalvani, A. Diagnosing tuberculosis infection in the 21st century. Chest 2007;131:1898–1906.CrossRefGoogle Scholar
11.Centers for Disease Control and Prevention. Guidelines for using the Quantiferon-TB Gold test for detecting Mycobacterium tuberculosis infection, United States (published correction appears in MMWR Morb Mortal Wkly Rep 2005;54:1288). MMWR Recomm Rep 2005;54(RR-15):49–56.Google Scholar
12.National Institute for Health and Clinical Excellence. Clinical Guidelines 33. Tuberculosis: clinical diagnosis and management of tuberculosis, and measures for its prevention and control. NICE document. London, UK: NICE, 2006:CG33.Google Scholar
13.Pollock, NR, Campos-Neto, A, Kashino, S, et al.Discordant Quanti-FERON-TB Gold test results among US healthcare workers with increased risk of latent tuberculosis infection: a problem or solution? Infect Control Hosp Epidemiol 2008;29:878–886.CrossRefGoogle ScholarPubMed
14.Nienhaus, A, Schablon, A, Le Bacie, C, Siano, B, Diel, R. Evaluation of the interferon-gamma release assay in healthcare workers. Int Arch Occup Environ Health 2008;81:295–300.CrossRefGoogle ScholarPubMed
15.Stebler, A, Iseli, P, Muhlemann, K, Bodmer, T. Whole blood interferon-gamma release assay for baseline tuberculosis screening of healthcare workers at a Swiss university hospital. Infect Control Hosp Epidemiol 2008;29:681–683.CrossRefGoogle Scholar
16.Harada, N, Nakajima, Y, Higuchi, K, Sekiya, Y, Rothel, J, Mori, T. Screening for tuberculosis infection using whole-blood interferon-γ and Mantoux testing among Japanese healthcare workers. Infect Control Hosp Epidemiol 2006;27:442–448.CrossRefGoogle ScholarPubMed
17.Soborg, B, Andersen, AB, Larsen, HK, et al.Detecting a low prevalence of latent tuberculosis among health care workers in Denmark detected by M. tuberculosis specific IFN-γ whole-blood test. Scand J Infect Dis 2007;39:554–559.CrossRefGoogle Scholar
18.Pai, M, Gokhale, K, Joshi, R, et al.Mycobacterium tuberculosis infection in health care workers in rural India: comparison of a whole-blood interferon gamma assay with tuberculin skin testing. JAMA 2005;293:2746–2755.CrossRefGoogle ScholarPubMed
19.Pai, M, Joshi, R, Dogra, S, et al.Serial testing of health care workers for tuberculosis using interferon-gamma assay. Am J Respir Crit Care Med 2006;174:349–355.CrossRefGoogle ScholarPubMed
20.Pai, M, O'Brien, R. Serial testing for tuberculosis: can we make sense of T cell assay conversions and reversions? PLoS Med 2007;4:e208.CrossRefGoogle ScholarPubMed
21. Ministry of Health, Singapore. Communicable diseases surveillance in Singapore 2007. Ministry of Health report. Singapore: Ministry of Health, 2008.Google Scholar
22.Chee, CBE, Soh, CH, Boudville, IC, Chor, SS, Wang, YT. Interpretation of the tuberculin skin test in Mycobacterium bovis BCG-vaccinated Singaporean schoolchildren. Am J Respir Crit Care Med 2001;164:958–961.CrossRefGoogle ScholarPubMed
23.Uplekar, M. Stopping tuberculosis: time to turn urgent attention to hospitals. Int J Pubere Lung Dis 2008;12:986.Google ScholarPubMed
24.Villarino, ME, Mazurek, G. Tuberculosis contacts, concerns, and controls: what matters for healthcare workers? Infect Control Hosp Epidemiol 2006;27:433–435.CrossRefGoogle ScholarPubMed
25.Wang, L, Turner, MO, Elwood, RK, Schulzer, M, FitzGerald, JM. A metaanalysis of the effect of BCG vaccination on tuberculin skin test measurements. Thorax 2002;57:804–809.CrossRefGoogle ScholarPubMed
26.Farhat, M, Greenaway, C, Pai, M, Menzies, D. False-positive tuberculin skin tests: what is the absolute effect of BCG and non-tuberculous mycobacteria? Int J Tuberc Lung Dis 2006;10:1192–1204.Google ScholarPubMed