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

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.

Between September 1^st 2019 and January 31^st 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.

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.

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.