Cough of more than two weeks - Time to think beyond pulmonary TB

Cough of more than two weeks has become sine quo non with pulmonary tuberculosis (PTB) in a developing country like India. The causes may be different in patients reporting to respiratory OPD vis a vis general OPD.

To study the prevalence of PTB and causes of cough other than PTB among respiratory OPD attendees with cough of more than two weeks duration.

A cross sectional study was carried out over two years in respiratory OPD of a tertiary care chest center of Indian armed forces. Of the 13,004 patients, 505 non HIV PTB suspects were included. Patients with definitive diagnosis of chronic cough were excluded. Efforts were made to establish diagnosis of pulmonary TB using clinical, microbiological and radiological features. However, patients were also subjected to further evaluation (spirometry, bronchoscopy, CECT) based on clinical features, radiological and lab profile to establish definitive diagnosis.

Out of the 505 patients, 10.5% patients had smear positive pulmonary TB, 13.5% smear negative PTB, bronchial asthma (24%), COPD (9.3%), diffuse parenchymal lung diseases (DPLD's) (12.5%), bronchiectasis (6.3%), lung cancer (5.3%) and congestive cardiac failure (4.2%).

Though prevalence of PTB in the study correlated well with the national statistics, but a significant number of patients had other causes of chronic cough, especially, obstructive airway diseases and DPLDs. Thus, there is a need to spread awareness regarding other causes of chronic cough and all efforts should be made to establish alternate diagnosis especially in patients who do not conclusively have PTB.