Background and objective: It is unclear whether patients with liver cirrhosis and coal miners with pneumoconiosis are at increased risk of developing pulmonary tuberculosis (TB). Furthermore, little is known of the likelihood of pneumonia in patients with bronchiectasis, haemodialysis, diabetes mellitus or advanced lung cancer being due to TB. To answer these questions, patients with these clinical comorbidities were analysed.
Methods: The study was retrospective and included 264 TB patients, 478 non-TB pneumonia patients, and as negative controls, 438 subjects without pneumonia. The parameters analysed were age, gender and the presence of pneumoconiosis, bronchiectasis, liver cirrhosis, haemodialysis, diabetes mellitus and advanced lung cancer.
Results: Male gender was the only significant factor increasing the risk of pulmonary TB. When compared with non-TB pneumonia and control patients, the odds ratios were 1.862 and 2.182, respectively. Patients with liver cirrhosis did not show an increased risk of pulmonary TB after regression analysis. Pneumoconiosis resulted in a 2.260 (P = 0.003) odds ratio for pulmonary TB, compared with the controls. However, there was no difference in pneumoconiosis between TB and non-TB pneumonia patients. Patients with bronchiectasis, lung cancer and those receiving haemodialysis had a lower risk for pulmonary TB in lower respiratory tract infection, with odds ratios of 0.342, 0.311 and 0.182, respectively.
Conclusion: Physicians should first consider non-TB bacterial infection rather than Mycobacterium tuberculosis infection in pneumonia in patients with bronchiectasis, lung cancer or those receiving haemodialysis.