Risk Factors for Tuberculosis

TLDR

The progression from exposure to active tuberculosis is a two‑stage process driven by exogenous factors such as bacillary load and proximity to infectious cases, and endogenous factors including HIV, malnutrition, young age, diabetes, indoor air pollution, alcohol, immunosuppressive drugs, tobacco smoke, socioeconomic and behavioral determinants, and high‑risk groups like health‑care workers and indigenous populations. This paper summarizes these risk factors and examines how health‑system delays in TB diagnosis influence bacillary transmission.

Abstract

The risk of progression from exposure to the tuberculosis bacilli to the development of active disease is a two-stage process governed by both exogenous and endogenous risk factors. Exogenous factors play a key role in accentuating the progression from exposure to infection among which the bacillary load in the sputum and the proximity of an individual to an infectious TB case are key factors. Similarly endogenous factors lead in progression from infection to active TB disease. Along with well-established risk factors (such as human immunodeficiency virus (HIV), malnutrition, and young age), emerging variables such as diabetes, indoor air pollution, alcohol, use of immunosuppressive drugs, and tobacco smoke play a significant role at both the individual and population level. Socioeconomic and behavioral factors are also shown to increase the susceptibility to infection. Specific groups such as health care workers and indigenous population are also at an increased risk of TB infection and disease. This paper summarizes these factors along with health system issues such as the effects of delay in diagnosis of TB in the transmission of the bacilli.