Comparison of pulmonary and extrapulmonary tuberculosis in Nepal - a hospital-based retrospective study

Background: Studies from developed countries have reported on host-related risk factors for extra-pulmonary tuberculosis (EPTB). However, similar studies from high- burden countries like Nepal are lacking. Therefore, we carried out this study to compare demographic, life-style and clinical characteristics between EPTB and PTB patients. Methods: A retrospective analysis was carried out on 474 Tuberculosis (TB) patients diagnosed in a tertiary care hospital in western Nepal. Characteristics of demography, life-style and clinical features were obtained from medical case records. Risk factors for being an EPTB patient relative to a PTB patient were identified using logistic regression analysis. Results: The age distribution of the TB patients had a bimodal distribution. The male to female ratio for PTB was 2.29. EPTB was more common at younger ages (< 25 years) and in females. Common sites for EPTB were lymph nodes (42.6%) and peritoneum and/or intestines (14.8%). By logistic regression analysis, age less than 25 years (OR 2.11 95% CI 1.12-3.68) and female gender (OR 1.69, 95% CI 1.12-2.56) were associated with EPTB. Smoking, use of immunosuppressive drugs/steroids, diabetes and past history of TB were more likely to be associated with PTB. Conclusion: Results suggest that younger age and female gender may be independent risk factors for EPTB in a high- burden country like Nepal. TB control programmes may target young and female populations for EPTB case-finding. Further studies are necessary in other high- burden countries to confirm our findings.