Cavities Herald Persistent Sputum Positivity

Abstract Aim: To determine the factors associated with persistent sputum positivity at the end of two months of treatment in patients presenting with (drug-susceptible) pulmonary tuberculosis at a tertiary care hospital in Karachi.Setting: A cross-sectional study was conducted at the Department of Chest Medicine (Ward 12), Jinnah Postgraduate Medical Center (JPMC), Karachi over six months.Methods: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, body mass index (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 two months of treatment with a sputum smear. Data analysis was done on SPSS-20.0.Results:Rate of sputum positivity after two months of treatment was 17.8%. None of the factors was associated with persistence of sputum positivity except for the presence of chest radiograph (CXR) cavities; which made it 5.5 times more likely that the patient would remain smear-positive at two months (p=0.035).Conclusion:The finding of CXR cavities makes it highly likely that a pulmonary tuberculosis patient may remain infectious or have an unfavourable 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 pay particular attention in terms of stringent monitoring and Directly Observed Treatment Short-course (DOTS) provision.