Tuberculosis examination using whole blood interferon-gamma release assay among health care workers in a Japanese hospital without tuberculosis-specific wards

Occupational latent tuberculosis infection (LTBI) among health care workers (HCWs) is an important public health issue. The objective of this study is to assess prevalence and risk factors of LTBI among Japanese HCWs by Quantiferon-TB Gold in Tube (QFT-GIT) and the structured questionnaire. This is a cross-sectional study involving HCWs from a hospital without tuberculosis-specific wards, receiving QFT-GIT for LTBI screening. We reviewed medical records of HCWs and questioned HCWs about exposure to M. tuberculosis and employment length in health care industries. 165 HCWs, approximately 80% of the total hospital staff, were enrolled in this study.18 out of 165 subjects had positive results, suggesting LTBI prevalence rate of 11%. Multiple regression analysis revealed a significant association between the positive or intermediate QFT-GIT results and history of contact investigation for tuberculosis. QFT-GIT positivity rate among HCWs is higher than among general population in Japan.