Predictors of tuberculosis and human immunodeficiency virus co-infection: a case-control study

OBJECTIVES: The human immunodeficiency virus (HIV) and Mycobacterium tuberculosis co-infection is a major global challenge It is not dear why some HIV-positive people are co-infected with tuberculosis while otheis are not.This study addressed that question. METHODS:This case-control study was conducted in Tehran, Iran in June 2004, enrolling 2,388 I IV-positive people. Cases were selected from those who were co-infected with TB and controls from those without TB. Multiple logistic regression analysis was performed to assess the association between M. tuberculosis/HIV co-infection and several predictors. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated. RESULTS: In this study, 241 cases were compared with 2,147 controls. Sex, age, marital status, educational level, imprisonment, smoking, narcotic use, route of H IV transmission, previous'111 infection, isoniazid preventive therapy (IFT), antiretroviral therapy (ART), and low CD4 count (<350 cells/mm 3 ) were independently associated with M. tubercuk)sisIIIIV co-infection (p <0.001). However, after adjusting for all other variables in the model, only the association between M. tuberculosislHlV co-infection and the following predictors remained statistically significant: imprisonment (odds ratio [OR], 3.82; 95% confidence interval [CI], 2.11-6.90), previous TB infection (OR, 5.54; 95% CI, 1.99-15.39), TM' (OR, 0.13; 95% CI, 0.06-0.31), ART (OR, 1.81; 95% CI, 1.26-2.61), and CD4 count <350 cells/mm(3) (OR, 2.34; 95% CI, 1.364.02). CONCLUSIONS: Several predictors are associated with M. tuberculosis/HIV co-infection, but only a few indicators were significantly associated with M. tuberculosis/H IV co-infection. It is estimated that a number of predictors of M. tuberculosis/HIV co-infection remain unknown and require further investigation.