Epidemiology and factors associated with Extra-pulmonary tuberculosis in a Low-prevalence area

BACKGROUND: Tuberculosis is a global public health problem. Extra-pulmonary tuberculosis accounts for an increasing proportion of cases worldwide, although information about epidemiological, clinical, or microbiological factors is lacking. METHODS: We conducted a retrospective observational study of tuberculosis cases diagnosed between 2016 and 2021, classified into Pulmonary and Extra-pulmonary tuberculosis. Univariable and multivariable logistic regression models were used to investigate risk factors of Extra-pulmonary tuberculosis. RESULTS: 20.9% of overall cases were classified as Extra-pulmonary tuberculosis, with a rising trend from 22.6% in 2016 to 27.9% in 2021. Lymphatic tuberculosis accounted for 50.6% of cases, followed by pleural tuberculosis (24.1%). 55.4% of cases belonged to foreign-born patients. Microbiological culture tested positive in 92.8% of Extra-pulmonary cases. Logistic regression analysis showed that women were more predisposed to develop Extra-pulmonary tuberculosis (aOR 2.46, 95% CI 1.45–4.20) as well as elderly patients (aged ≥ 65 years) (aOR 2.47, 95% CI 1.19–5.13) and persons with previous history of tuberculosis (4.99, 95% CI 1.40–17.82). CONCLUSIONS: Extra-pulmonary Tuberculosis have increased within our study period. A profound decline occurred in 2021 tuberculosis cases, probably due to COVID-19. Women, elderly population, and persons with previous history of tuberculosis are at higher risk of developing Extra-pulmonary tuberculosis in our setting.