Prevalence, screening and treatment of latent tuberculosis among oral corticosteroid recipients.

To the Editor: Tuberculosis guidelines identify individuals receiving the corticosteroid drug prednisone (or its equivalent) at a dose of >15 mg·day−1 for 2–4 weeks or more as a group at risk of tuberculosis if infected with Mycobacterium tuberculosis [1, 2]. There is an eight-fold increased risk of developing active tuberculosis with such drugs at this dose [3]. However, there is no information on the epidemiology of latent tuberculosis infection (LTBI), screening and treatment among oral corticosteroid users. Tuberculosis guidelines recommend using a threshold of ≥5 mm induration to identify latent infection among oral corticosteroid recipients [1, 2] but this recommendation is not evidence-based. The purpose of this study was to describe the prevalence, screening and treatment of LTBI among oral corticosteroid recipients in the USA. This was a cross-sectional study using US nationally representative, population-level data from the 1999–2000 National Health and Nutrition Examination Survey (NHANES). A description of the survey design and methodology appears elsewhere [4]. Self-reported medication receipt within the past month that required a prescription was collected by NHANES. Medication receipt was confirmed in 83.3% of participants through examiner inspection of prescription containers [5]. Survey participants who received any corticosteroid in an oral formulation within the past month were considered “recipients”. Survey participants who did not receive any oral corticosteroids within the past month were considered “nonrecipients”. Topical, inhaled or intra-articular corticosteroids were not included in this study. Information on total duration of corticosteroid receipt was collected but not dose. A single-step tuberculin skin test (TST) …