Clinical and Imaging Features of Adults with Recurrent Pulmonary Tuberculosis - A Prospective Case-Controlled Study.

Background: Recurrent pulmonary tuberculosis (RPTB) is a growing, important and neglected problem affecting treated TB patients and TB health services across the world, particularly in sub-Saharan Africa. Analyses and identification of differences in clinical features between recurrent PTB and newly diagnosed PTB may lead to improved management recommendations.

Methods: Between September 1 2019 and January 31 2020, we performed a prospective case controlled study of clinical and imaging features of patients with recurrent pulmonary tuberculosis and compared them with those of newly diagnosed PTB cases. Recurrent PTB was defined as a patient with bacteriologically confirmed active PTB who was previously successfully treated for PTB and was cured. A control was defined as a patient who presents for the first time with bacteriologically confirmed PTB. Clinical and radiological features were assessed and documented. Chi-square and t-test were used to test the difference between proportion and continuous data, respectively. Logistic regression analysis was done to determine factors associated with RPTB using SPSS version 23 software.

Results: A total of 312 patients with PTB were enrolled (104 RPTB cases and 208 newly diagnosed controls). Clinically hemoptysis was more common in RPTB compared to controls 28/104 (26.9%) vs 35/208 (16.8%), P = 0.036. Chest pain was significantly less common among patients with RPTB compared to controls 33 (31.7%) vs 92 (44.2%), P = 0.034. A higher proportion of RPTB presented with cavitation 34/104 (32.7%) compared to control 44/208 (21.2%) P = 0.027. The median score for lung pathology was higher among patients with RPTB (50) compared to controls (30); P = 0.001. Lung function of patients with RPTB at diagnosis of index TB were more likely to show mixed restrictive and obstructive pattern 36/104 (34.6%) compared to controls 31/208 (14.9%). p<0.001. Multivariate analysis showed that patients older than 45 years of age (adjusted odds ratio [aOR]: 3.59, 95% CI: 1.38 - 9.32), those with hemoptysis (aOR 1.96, 95% CI: 1.04 - 3.69) p=0.04) and fibrosis on chest x rays (aOR 2.18, 95% CI: 1.16 - 4.10) were significantly associated with recurrent PTB.

Conclusions: Hemoptysis, lung parenchymal damage, and patients being older than 45 years of age are significant features of RPTB. Management should focus on risk factors for recurrence, and a more holistic model of care to prevent long term lung injury.