Chia SZG, et al. - Healthcare workers (HCWs) exposed to index tuberculosis (TB) patients were evaluated for TB acquisition rate and for the associated risk factors. At a tertiary hospital in Singapore, exposed HCWs were retrospectively studied from August 2016 to January 2018. During the study period, researchers identified the occurrence of 32 TB exposure events. Using QuantiFERON-TB Gold In-tube assay (QFT-GIT), they screened 881 HCWs with 1,536 exposure episodes at baseline and 8 weeks. Positive QFT-TB was reported in 129 (14.6%) HCWs at baseline, whereas 22 (2.5%) HCWs showed QFT-GIT conversion, with a latent TB infection (LTBI) rate of 1.14 cases per 100 exposure episodes per year. These findings are indicative of a low QFT-GIT conversion rate among screened HCWs. Baseline LTBI was noted in independent correlation to foreign nationality, non-Chinese ethnicity, and age above 40 years, whereas QFT-GIT conversion was observed in correlation to having > 2 TB exposure episodes and working in internal medicine, medical subspecialties, and psychiatry wards. The investigators recommended undertaking targeted prevention of repeated TB exposures for decreasing QFT-GIT conversion.