Tuberculin skin test versus QuantiFERON-TB gold in-tube for latent tuberculosis screening in people living with HIV in a resource-limited setting.

Abstract

To compare QuantiFERON-TB Gold-in-Tube (QFT) and tuberculin skin test (TST) in the diagnosis of latent tuberculosis infection (LTBI) among people living with HIV (PLWHIV). A cross-sectional study was carried out between 2017-2018. Tuberculin skin test and QFT were performed and their concordance was measured. The gold standard for LTBI was defined as positivity to any of the tests. A logistic regression model was carried out to predict the QFT result in patients with a negative TST. A total of 510 PLWHIV were included, with 409 (80.2%) being male. The mean age of the patients was 41.3 ± 11.8years. The median time since HIV diagnosis was 5years (IQR 2-10), with a median CD4+ count of 541 (IQR 340-757) cells/mm3. Overall, 20 patients had an isolated TST+, 22 an isolated QFT+ and 15 had both positive. Concordance between tests showed a kappa coefficient of .37. Overcrowding was the only predictor for a positive QFT after a negative TST (p = .003). There was fair agreement between tests in PLWHIV. In conditions of limited access to QTF, a TST-based strategy could be considered, with sequential use of QTF in high-risk patients with a negative result, especially those who live in overcrowded conditions.