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

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.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.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.Tuberculosis (TB) remains a major global public health problem [1]. It is estimated that about one-third of the world's population is infected with mycobacterium tuberculosis [2]. After primary infection, TB may reactivate at anytime and anywhere in the body. Recent studies have suggested that the sites of extra-pulmonary tuberculosis (EPTB) may vary according to geographic location and population [3-6]. Clinical manifestations of TB are variable and depend on a number of factors that are related to the microbe, the host and the environment [7]. Our understanding of the role of host-related factors responsible for the occurrence of TB at extra-pulmonary sites is limited. Some studies have reported that the proportion of TB that is EPTB is on the rise due to the HIV epidemic [8,9] and possibl