Factors associated with extrapulmonary tuberculosis in comparison to pulmonary tuberculosis in patients with and without HIV in Bogotá, Colombia: an observational study.

BACKGROUND

Extrapulmonary tuberculosis (EPTB) poses a public health challenge, particularly among individuals with human immunodeficiency virus (HIV). However, many EPTB cases arise in those without HIV, leaving the underlying factors unclear.

OBJECTIVES

This study aims to characterize patients with pulmonary tuberculosis (PTB) and EPTB, exploring the differences in associated factors for each type in patients with and without HIV.

DESIGN

An analytical observational study was conducted on a cohort of tuberculosis (TB) patients diagnosed between 2014 and 2021 in a referral hospital in Bogotá, Colombia.

METHODS

Patients were categorized into PTB or EPTB based on the site of infection. Data on demographic and clinical variables were collected, comparing the two groups. A multivariate logistic regression model was created to identify factors associated with EPTB compared to PTB.

RESULTS

The study encompassed 533 patients: 310 with PTB and 223 with EPTB, of which only 65 (14.7%) were HIV positive. PTB patients exhibited higher rates of active smoking, smoking cessation, diabetes mellitus (DM), and other pulmonary diseases. The logistic regression identified HIV infection as the only factor associated with EPTB (OR 2.36 (1.54-3.61),  < 0.001). Conversely, quitting smoking (OR 0.58 (0.35-0.96)  = 0.038), DM (OR 0.41 (0.21-0.82)  = 0.011), chronic obstructive pulmonary disease (COPD) (OR 0.18 (0.08-0.4)  < 0.001), other pulmonary diseases (OR 0.21 (0.61-0.77)  = 0.019), or those using immunosuppressants (OR 0.44 (0.20-0.96)  = 0.04) exhibited a negative association with EPTB compared to PTB. Specific models for pleural and lymph node TB revealed distinct associations, with HIV strongly linked to lymph node TB (OR 3.38, 95% CI 1.57-7.26,  = 0.002).

CONCLUSION

EPTB is primarily associated with HIV infection, while smoking, DM, COPD, other pulmonary diseases, and immunosuppressant use are associated with PTB. Variability in associated factors for specific EPTB forms underlines the need for tailored research into the predisposing factors for EPTB, particularly in HIV-negative patients.