COMBINED USE OF INTERFERON-GAMMA RELEASE ASSAY AND LOW-DOSE COMPUTED TOMOGRAPHY FOR TUBERCULOSIS SCREENING PROGRAM OF HEALTH CARE WORKERS

Abstract

[Objective] To evaluate the value of the interferon-gamma release assays and low-dose computed tomography for the pulmonary tuberculosis screenings program of health care workers. [Design] For the pulmonary tuberculosis (TB) screenings program, T-SPOT^®.TB (one of interferon-gamma release assays: IGRA) were performed on 332 health care workers (HCWs) with normal chest roentgenogram and without the history of TB treatment. Low-dose computed tomography (LDCT) was also performed on IGRA positive HCWs. [Results] Ten of 332 subjects were positive IGRA. LDCT was performed on IGRA positive 10 subjects. Abnormal findings were noted in 2 of 10 subjects by LDCT. One had CT findings compatible with active TB and finally diagnosed as active TB. Another had scarring shadow at right S5 and lingular segment. Nine of 10 IGRA positive subjects were judged as latent tuberculosis infection (LTBI). Three hundred twenty-one subjects with negative and borderline IGRA of 332 HCWs were judged as not infected with TB. [Conclusion] Combined use of IGRA and LDCT for tuberculosis screening program of HCWs was found to be effective for early diagnosis of TB, accurate diagnosis of LTBI and judgment of non-infective subjects.