What do we know about the outcomes of tuberculosis contact investigations in NSW?

A recently conducted study on tuberculosis contact investigations in six Sydney tuberculosis clinics - that together managed 59% of all tuberculosis cases in NSW from January 2000 to December 2009 - found that the prevalence of tuberculosis among contacts was comparable to other low-incidence settings. However, only 9% of contacts with latent tuberculosis infection received treatment. This paper explores the results of the study, evaluating potential missed opportunities to prevent tuberculosis among contacts, and discussing the mechanisms in decision making about treatment of latent tuberculosis infection. In particular, the paper focuses on the challenges of tuberculin skin test interpretation among contacts who have received Bacille Calmette-Guérin vaccination and who were born in countries where tuberculosis is endemic.