Prevalent and incident latent tuberculosis infection among healthcare workers in Taiwan: A multi-center observational study

BACKGROUND: Healthcare workers (HCWs) have increased risks of active tuberculosis, yet there are limited reports of incidence and risk factors of latent tuberculosis infection (LTBI) among HCWs. METHODS: HCWs were enrolled from four medical centers in Taiwan. Quantiferon-TB Gold Plus Test (QFT-Plus) was performed initially and 9-12 months afterwards. The prevalence, incidence, and clinical factors associated with LTBI, and willingness to receive LTBI treatment were explored. RESULTS: Among 297 HCWs, the prevalence rate of LTBI was 10.8 %. The independent factors associated with prevalent LTBI were age >40 years old (aOR 3.52, 95 % CI 1.46-8.45), health professionals (aOR 3.99, 95 % CI 1.02-15.65), and working in intensive care units (ICUs) (aOR 4.06, 95 % CI 1.28-12.86). Having all three factors escalated the risk of prevalent LTBI (aOR 13.81, 95 % CI 3.16-60.37). Of 129 LTBI-free HCWs undergoing 2nd QFT-Plus, seven (5.4 %) had positive conversion, indicating incident LTBI, among which four had TB contacts without wearing N95 mask. Two had a TB2-TB1 value > 0.6 IU/ml. 40.6 % prevalent LTBI patients refused LTBI preventive therapy. CONCLUSIONS: More advanced age, health professionals, and working in ICUs were independent factors associated with prevalent LTBI. Most healthcare workers with incident LTBI cases had TB contacts without wearing N95 masks.