Associated Risk Factor of Tuberculosis Infection Among Adult Patients in Gedeo Zone, Southern Ethiopia

Background: Tuberculosis remains a major global health problem causing death among millions of people each year. Even though many of the World Health Organization recommended tuberculosis control strategies were implemented, there is still a major gap in tuberculosis case detection and treatment which resulted in rapid transmission of the cases in high burden countries. This study aimed to provide updated information on the contributing factors for the development of tuberculosis.

Methods: A case-control study was carried out in Gedeo Zone from February to July 2021 to assess the risk factors of tuberculosis. Cases were confirmed pulmonary tuberculosis patients with age ⩾18 years, while controls were participants who were confirmed to be pulmonary tuberculosis negative with the same age. Multivariate logistic regression models were used to assess the associated risk factor.

Results: A total of 368 individuals (173 cases and 173 controls) were included in this study. Based on the multivariable logistic regression analysis, we identified six variables as independent risk factors for the development of tuberculosis after controlling possible confounders. Those were patients with income <1500 Ethiopian birr per month (adjusted odds ratio = 2.35; 95% confidence interval: 1.22-3.97), patients with no educational background (illiterate) (adjusted odds ratio = 2.10; 95% confidence interval: 1.17-2.51), patients smoking cigarette (adjusted odds ratio = 2.89; 95% confidence interval: 2.10-3.82), patients chewing khat (adjusted odds ratio = 2.86; 95% confidence interval: 1.28-3.79), patients in close contact with known tuberculosis cases (adjusted odds ratio = 3.63; 95% confidence interval: 2.24-4.46), and patients being positive for HIV (adjusted odds ratio = 3.01; 95% confidence interval: 1.07-3.52) who were found to be significantly associated with tuberculosis development, while Bacille Calmette-Guérin vaccination had a protective effect against the development of tuberculosis (adjusted odds ratio = 0.52; 95% confidence interval: 0.21-0.88).

Conclusion: The priority should be given to the identified contributing factors through application of coordinated efforts on screening of patients suspected for pulmonary tuberculosis and all contacts of pulmonary tuberculosis patients and treatment of known tuberculosis cases, and appropriate control methods to reduce cases.