Tuberculosis contact tracing — DTM&H MCQ

Correct answer: D — Screen close contacts and prioritise symptomatic people and young children

The correct answer is D, screen close contacts and prioritise symptomatic people and young children. UK TB control follows a stone in the pond model of contact tracing, starting with the closest, highest risk contacts of a smear positive pulmonary case and expanding outward only if transmission is found. Children under 5 years are at markedly increased risk of rapid progression to severe disease, including miliary TB and meningitis, after infection, and symptomatic adults such as the man with chronic cough and weight loss need urgent assessment and sputum testing to detect further infectious cases. This targeted, risk stratified screening identifies latent and active infection early, allows prompt treatment, and interrupts transmission in a crowded congregate setting without the harms of blanket intervention. Why the other options are wrong: E. Treat every resident with multidrug TB therapy: giving multidrug anti-TB drugs to unconfirmed cases exposes people needlessly to hepatotoxicity and other adverse effects and risks driving resistance; treatment follows confirmed active or latent infection after screening. C. Close the hostel permanently: this disproportionate measure does not identify or treat infected individuals and simply displaces residents, worsening contact tracing and continuity of care. B. Vaccinate adults with BCG as the main control step: BCG has limited efficacy in adults, does not treat existing infection, and is not the primary outbreak control tool where contact screening and treatment take precedence. A. Wait for drug susceptibility before contact assessment: contact tracing must begin promptly once an index case is smear positive; delaying assessment for susceptibility results allows ongoing transmission, particularly to vulnerable young children. Key point: In UK TB outbreaks, contact tracing is risk stratified, prioritising close, symptomatic and paediatric (under 5) contacts of a smear positive case for prompt screening and treatment.

Reference: NICE Guideline NG33, Tuberculosis: prevention, diagnosis, management and organisation of services (2016, updated 2024), Recommendations on identifying and managing contacts, https://www.nice.org.uk/guidance/ng33/chapter/recommendations