Clinical characteristics of tuberculosis patients in a tertiary hospital

We retrospectively assessed the clinical characteristics of tuberculosis patients in a tertiary hospital. The subjects consisted of 80 patients who Mycobacterium tuberculosis was isolated from clinical specimens and who received a definite diagnosis of tuberculosis in our tertiary hospital without isolated bedrooms between January 2010 and June 2018. The average age of the 80 patients was 68.3 years old, consisting of 43 males and 37 females (6 non-Japanese). Sixty-eight patients had underlying diseases, and malignant diseases were most frequently recognized. Seven patients were diagnosed as outpatients and the remaining patients were diagnosed after admission. The final diagnose consisted of 56 patients with pulmonary tuberculosis and 35 patients with extrapulmonary tuberculosis (tuberculous lymphadenitis, tuberculous pleurisy, miliary tuberculosis, etc.). Concerning the results of interferon-γ release assays (IGRAs), while the positive response rate of QFT was 75%, that of T-SPOT was 81%. The clinical specimens used to diagnose tuberculosis were as follows: expectorated sputum, 26 patients; bronchoscopic specimens, 32; biopsy tissue, 17; and others, 5. The interval from the first consultation to diagnosis was three months at the maximum and within one month in most patients. Regarding radiological findings, pulmonary lesions including miliary tuberculosis showed various atypical findings: 39 of 66 patients with bilateral lesions; 50 with no cavity lesion; and 13 with the extent of the lesion exceeding the unilateral lung field. Tuberculosis patients in our tertiary hospital had many underlying diseases such as malignant or autoimmune diseases and were receiving immunosuppressive treatment. Therefore, because IGRAs do not always show a positive response and radiological findings also do not show typical findings, it is important to investigate acid-fast bacilli for various clinical specimens and actively perform diagnostic methods including bronchoscopy in order to prevent nosocomial infection.

Kobashi Y, et al