TY - JOUR
T1 - Comparison of the interferon-gamma; release assay and the tuberculin skin test for contact investigation of tuberculosis in BCG-vaccinated health care workers
AU - Lee, Susan Shin Jung
AU - Liu, Yung Ching
AU - Huang, Tsi Shu
AU - Chen, Yao Shen
AU - Tsai, Hung Chin
AU - Wann, Shue Ren
AU - Lin, Hsi Hsun
N1 - Funding Information:
This study was supported by grants from the National Health Research Institutes, Department of Health, Executive Yuan, Republic of China (NHRI-CN-LL-9301S) and Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan (VGHKS 94-22).
PY - 2008
Y1 - 2008
N2 - Health care workers are at increased risk of Mycobacterium tuberculosis infection. The tuberculin skin test (TST) is frequently false positive in BCG-vaccinated health care workers. QuantiFERON-TB GOLD (QFT-G) is a sensitive and specific interferon-γ release assay unaffected by BCG vaccination. This study compared TST and QFT-G in the diagnosis of latent TB infection in BCG-vaccinated health care workers. 39 health care workers exposed to a smear-positive TB patient were enrolled. Initial TST was positive in 33 (84.6%) cases, but only 4 (10.2%) cases using QFT-G. TST conversion occurred in 2/6 (33.3%), compared to 4/ 32(12.5%), cases using QFT-G. A higher proportion of QFT converters was associated with intimate contact, although not reaching statistical significance. Face-to-face contact >1 h was significantly associated with QFT-G conversion ≥0.7 IU/ml (OR 8.63,95% 1.08-69.07, p=0.04). Agreement between TST and QFT-G was 18.0%, (κ -0.03). Concordance between TST and QFT (≥0.35 IU/ml) conversion was 40.0%(κ=-0.40), and 60.0%(κ=0.00) if QFT ≥0.7 IU/ml was used. Agreement increased with increasing TST cut-offs. TST is not useful in contact investigation among BCG-vaccinated health care workers, in an area with intermediate burden of TB. QFT may provide additional information for the diagnosis and strategic management of preventive treatment of LTBI in BCG-vaccinated health care workers in a country with intermediate burden of TB.
AB - Health care workers are at increased risk of Mycobacterium tuberculosis infection. The tuberculin skin test (TST) is frequently false positive in BCG-vaccinated health care workers. QuantiFERON-TB GOLD (QFT-G) is a sensitive and specific interferon-γ release assay unaffected by BCG vaccination. This study compared TST and QFT-G in the diagnosis of latent TB infection in BCG-vaccinated health care workers. 39 health care workers exposed to a smear-positive TB patient were enrolled. Initial TST was positive in 33 (84.6%) cases, but only 4 (10.2%) cases using QFT-G. TST conversion occurred in 2/6 (33.3%), compared to 4/ 32(12.5%), cases using QFT-G. A higher proportion of QFT converters was associated with intimate contact, although not reaching statistical significance. Face-to-face contact >1 h was significantly associated with QFT-G conversion ≥0.7 IU/ml (OR 8.63,95% 1.08-69.07, p=0.04). Agreement between TST and QFT-G was 18.0%, (κ -0.03). Concordance between TST and QFT (≥0.35 IU/ml) conversion was 40.0%(κ=-0.40), and 60.0%(κ=0.00) if QFT ≥0.7 IU/ml was used. Agreement increased with increasing TST cut-offs. TST is not useful in contact investigation among BCG-vaccinated health care workers, in an area with intermediate burden of TB. QFT may provide additional information for the diagnosis and strategic management of preventive treatment of LTBI in BCG-vaccinated health care workers in a country with intermediate burden of TB.
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U2 - 10.1080/00365540701730743
DO - 10.1080/00365540701730743
M3 - Article
C2 - 18418798
AN - SCOPUS:42549155422
SN - 0036-5548
VL - 40
SP - 373
EP - 380
JO - Scandinavian Journal of Infectious Diseases
JF - Scandinavian Journal of Infectious Diseases
IS - 5
ER -
