Tuberculosis Contact Investigation Using Interferon-Gamma Release Assay with Chest X-Ray and Computed Tomography

• Published in: PloS one Vol. 9; no. 1; p. e85612
• Main Authors: Fujikawa, Akira, Fujii, Tatsuya, Mimura, Satoshi, Takahashi, Ryota, Sakai, Masao, Suzuki, Shinya, Kyoto, Yukishige, Uwabe, Yasuhide, Maeda, Shinji, Mori, Toru
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14.01.2014; Public Library of Science (PLoS)
• Subjects: Adult; Antigens; Biological response modifiers; CAT scans; Chest; Computed tomography; Contact Tracing; Epidemics; Epidemiology; Health aspects; Health education; Hospitals; Humans; Immunization; Infections; Infectious diseases; Interferon; Interferon-gamma Release Tests; Internal medicine; Investigations; Medical diagnosis; Medical imaging; Medicine; Middle Aged; Military Personnel; Military training; Mycobacterium tuberculosis; Radiography, Thoracic; Screening; Self defense; Sensitivity and Specificity; Systematic review; Tomography; Tomography, X-Ray Computed; Tuberculosis; Tuberculosis - diagnosis; Tuberculosis - diagnostic imaging; Tuberculosis - transmission; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0085612

Between September 2009 and January 2010, 6 members of the Japanese Eastern Army, who had completed the same training program, were diagnosed with active tuberculosis (TB) on different occasions. The Ministry of Defense conducted a contact investigation of all members who had come into contact with the infected members. The purpose of this study was to verify the efficacy of the TB screening protocol used in this investigation. A total of 884 subjects underwent interferon-gamma release assay (IGRA) and chest X-ray. The 132 subjects who were IGRA positive or with X-ray findings suggestive of TB subsequently underwent chest computer tomography (CT). Chest CT was performed for 132 subjects. Based on CT findings, 24 (2.7%) subjects were classified into the active TB group, 107 (12.1%) into the latent tuberculosis infection (LTBI) group, and 753 (85.2%) into the non-TB group. The first 2 groups underwent anti-TB therapy, and all 3 groups were followed for 2 years after treatment. Although one subject in the active TB group experienced relapse during the follow-up period, no patient in the LTBI or non-TB groups developed TB. IGRA and chest X-ray, followed by chest CT for those IGRA positive or with suspicious X-ray findings, appears to be an effective means of TB contact screening and infection prevention.