The Cavity as a Lasting Abode for Tuberculous Bacilli: An Observational Study

The aim of this study was to determine the factors associated with persistent sputum positivity at the end of 2 months of treatment in patients presenting with (drug-susceptible) pulmonary tuberculosis at a tertiary care hospital in Karachi. A cross-sectional study was conducted at the Department of Chest Medicine (Ward 12), Jinnah Postgraduate Medical Center (JPMC), Karachi, over 6 months. A sample of 73 consenting, newly diagnosed, smear-positive drug-susceptible pulmonary tuberculosis patients was studied. Demographic (age, gender, height, weight and duration of tuberculosis, BMI, socioeconomic, occupational, marital, educational and residential statuses) and clinical factors (chest X-ray extent and cavities, initial smear results, diabetic and smoking statuses) which may be associated with sputum non-conversion were entered in a proforma. Patients were followed up at 2 months of treatment with a sputum smear. Data analysis was done on SPSS (Statistical Package for Social Sciences-version 20.0). Rate of sputum positivity after 2 months of anti-tubercular drug treatment was 17.8%. None of the above-mentioned demographic and clinical factors was associated with persistence of sputum positivity except for the presence of CXR cavities, which made it 5.5 times more likely that the patient would remain smear-positive at 2 months (p = 0.035). The finding of chest radiograph cavities makes it highly likely that a pulmonary tuberculosis patient may remain infectious or have an unfavorable outcome despite taking treatment for 2 months. Clinicians and national policy-makers should thus bear in mind the implications this can have with regard to disease control and therefore pay particular attention to such patients in terms of stringent monitoring and directly observed treatment short-course (DOTS) provision. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42399-021-01098-6.