Factors Associated With Extrapulmonary Tuberculosis in Southeastern Mexico: A Case-Control Study

Extrapulmonary tuberculosis (EPTB) is a disease that can affect any organ or tissue. Due to its potential to cause more dangerous sequelae and the barriers to its timely diagnosis, greater clinical awareness of this disease is crucial. This study aimed to identify the factors associated with EPTB in the population of Oaxaca, Mexico.

This is an unpaired case-control study. The cases were patients with EPTB+ while the controls were patients with pulmonary tuberculosis (PTB+) registered in the Tuberculosis Epidemiological Surveillance System. Sociodemographic, clinical, and microbiological variables were recovered. Bivariate analyses were performed and logistic regression analyses were performed to calculate the odds ratio (OR).

A total of 75 EPTB+ cases and 300 PTB+ controls were included. Of the total sample, 57.1% were men and 60.3% indigenous. The most frequent clinical presentations of EPTB+ were nodal (21.3%), miliary (21.3%), and breast (20.0%). According to logistic regression analysis, age <40 years (OR: 2.25 (95% CI: 1.13-4.49), female sex (OR: 1.92 (95% CI: 1.03-3.56)], urban residence (OR: 2.25 (95% CI: 1.11-4.55)), comorbidity with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) (OR: 3.46 (95% CI: 1.31-9.10)), dyspnea (OR: 2.67 (1.22-5.82)), and adenopathy (OR: 3.38 (95% CI: 1.42-8.06)) were positively associated with EPTB+.

These results can serve as a basis for screening EPTB+, thus improving the preventive and diagnostic capacity of local health services, taking as a starting point women under 40 years of age and patients with HIV/AIDS in urban areas, as well as the presence of adenopathy and dyspnea as clinical characteristics of the disease.