LAUSR

Treatment of latent tuberculosis infection (LTBI) reduces the risk of progression to active tuberculosis (TB) disease among people living with HIV (PLWH). While the World Health Organization advocates universal LTBI screening of PLWH [1], current British HIV Association (BHIVA) guidelines from 2011 recommend a targeted approach with individuals at high risk of TB infection or disease selected on the basis of their country of origin, duration of antiretroviral therapy (ART) and CD4 count (Table 1) [2]. National Institute for Health and Care Excellence (NICE) guidelines similarly recommend targeted screening, but based on CD4 count < 200 cells/lL alone [3]. BHIVA recommends screening by interferon gamma release assay (IGRA), while NICE recommends concurrent tuberculin skin test (TST). Our local departmental guidelines, derived by consensus among clinicians in 2014, recommend screening by IGRA of all newly diagnosed PLWH who have lived outside the UK for > 2 years. The complexity and inconsistency of guidelines may present an obstacle to the implementation of LTBI screening in practice. Indeed, a recent survey of LTBI screening policies of UK HIV centres revealed substantial variation in the eligibility criteria and tests used [4], and a previous single-centre audit identified poor adherence to BHIVA 2011 screening guidelines [5]. The proposed BHIVA 2017 TB guidelines currently under consultation simplify requirements for individuals from high and medium TB incidence settings by removing the CD4 and ART criteria, but suggest additional criteria to prompt screening including chronic kidney disease, diabetes, use of immunosuppressive medication and injecting drug use (see Table 1) [6]. We audited LTBI screening practice against current BHIVA, NICE and local guidelines (Table 1) among patients with newly diagnosed HIV infection or a first UK review for HIV care who were first seen by our service between 1 February 2016 (following NICE guidelines publication) and 13 October 2017. We also projected the impact of screening recommendations in the proposed BHIVA 2017 guidelines. Of the 103 individuals identified [80 (77.7%) male; median age 35.8 years (interquartile range 28.3–45.0 years)], 77 (74.8%) were newly diagnosed, 26 (25.2%) had a CD4 count < 200 cells/lL and 30 (29.1%) were from a medium or high TB incidence country. BHIVA 2011 guidelines recommended screening in 54 patients (52.4%), encompassing all 26 (25.2%) for whom screening was recommended by NICE (Table 1). LTBI screening by IGRA was performed in 25 patients (24.3%) and positive in two patients (8.0%). Disregarding the lack of TSTs (none were performed), screening was completed in accordance with NICE, BHIVA 2011 and local guidelines in 30.2, 30.8 and 34.6% of patients, respectively. Completion of screening was associated with female sex [odds ratio (OR) 3.33; 95% confidence interval (CI) 1.19– 9.36; P = 0.02; v test] and origin in medium or high TB incidence countries (OR 4.93; 95% CI 1.77–13.78; P = 0.001), but did not vary with CD4 count or ART use. If adopted in their current form, BHIVA 2017 guidelines would have recommended screening in 67 patients (65.0%); an increase of 24% and 158% over current BHIVA and NICE guidelines, respectively. A simplified rule of screening all PLWH from a medium or high TB incidence country or with a CD4 count < 350 cells/lL identified 52 (77.6%) of these patients. While rationally targeting those most at risk, selective LTBI screening in PLWH introduces complexity that may be a barrier to effective implementation. In keeping with the experience of another UK HIV centre [5], we found Correspondence: Dr Stephen J. Aston, Institute of Infection and Global Health, University of Liverpool, Ronald Ross Building, 8 West Derby Street, Liverpool L69 7BE, UK. Tel: +44 151 795 9667; fax: 0151 795 5527; e-mail: [email protected]