Key risk factors for pulmonary vs. extrapulmonary tuberculosis: a comparative study in Southwest Ethiopia

Abstract

Background The intricate interplay of biological factors, living conditions, behaviors, co-morbidities like diabetes and HIV influences tuberculosis (TB) risk. In this study, those critical factors were identified to address gaps in understanding and improve prevention strategies. Methods A cross-sectional study was conducted across three zones to identify key risk factors for active TB. Diagnosis was based on smear microscopy, GeneXpert, clinical evaluation, and X-ray findings. A multistage sampling method was used, with a target of 384 participants from each zone, but due to inconsistencies, 410 were consecutively enrolled: 358 (87.3%) from Bench-Sheko, 23 (5.6%) from Sheka, and 29 (7.1%) from Kaffa.Data were collected through structured interviews and record reviews from December 2018 to June 2020 and analyzed using Stata. Results The study included 410 TB patients (55% male, mean age 27.7 ± 11.4 yrs.). Most (99.3%) were newly diagnosed, with PTB (80%), EPTB (19.3%), and both (0.7%). Concrete housing raised PTB (OR = 37.92) and lowered EPTB (OR = 0.03). Corrugated housing raised PTB (OR = 2.04) and lowered EPTB (OR = 0.491). Houses with 1–3 windows lowered PTB, raised EPTB. Separate bedrooms raised PTB (24.2%) and lowered EPTB (19.5%). Charcoal use lowered PTB (81.4%) and raised EPTB (OR = 5.39). Gas, electricity, and cohabitation reduced PTB odds (OR = 0.40, OR = 0.05, OR = 0.450) but increased EPTB odds (OR = 2.50, OR = 21.1, OR = 2.22, respectively). Raw milk reduced PTB odds (OR = 0.51) and increased EPTB odds (OR = 1.96, both p = 0.02). Alcohol raised PTB odds (OR = 4.44, p = 0.00) and lowered EPTB odds (OR = 0.23, p = 0.00). Awareness of transmission increased PTB odds (OR = 2.72, p = 0.05) and reduced EPTB odds (OR = 0.37, p = 0.05). HIV/AIDS increased PTB odds (OR = 1.78) and reduced EPTB odds (OR = 0.56). Coinfections raised PTB odds (OR = 1.36), lowered EPTB odds (OR = 0.73). Conclusions The findings revealed that housing, environment, and lifestyle influenced PTB and EPTB risks, with mixed and contrasting effects, highlighting the need for targeted interventions.