TuberkuloseScreening

TuberkuloseScreening refers to the process of identifying individuals who may have tuberculosis (TB) or latent TB infection (LTBI) in a population or group. The goal is to prevent transmission, diagnose disease early, and reduce TB-related illness and deaths. Screening distinguishes between active TB, which is contagious, and LTBI, which is asymptomatic but can progress to active disease if untreated.

Common screening methods include the tuberculin skin test (TST, Mantoux) and interferon-gamma release assays (IGRAs). A positive TST or IGRA indicates TB infection but does not by itself prove active TB; it requires clinical assessment and diagnostic testing. Chest radiography is often used to evaluate for active TB and to support decision-making after a positive test, though it cannot reliably detect LTBI.

Screening programs target groups with higher risk of infection or progression to disease, such as close contacts of infectious cases, people living with HIV, migrants from high-prevalence areas, residents of congregate settings, and healthcare workers. Some programs perform outreach in high-burden communities, while general population screening remains uncommon in low-incidence regions due to cost-effectiveness considerations.

Following a positive screen, further evaluation typically includes symptom review, sputum testing (microscopy, culture, and molecular assays), and chest imaging to distinguish active TB from LTBI. If active TB is excluded, people with LTBI may be offered preventive treatment to reduce the risk of progression.

Limitations of screening include variable sensitivity and specificity of tests, the influence of prior vaccination (e.g., Bacillus Calmette-Guerin) on TST results, and resource constraints. Ethical considerations include informed consent, confidentiality, and avoiding stigmatization. Guidelines from organizations such as the WHO, CDC, and regional health authorities shape program design and recommended regimens for LTBI treatment.