Korean J healthc assoc Infect Control Prev.  2019 Dec;24(2):52-59. 10.14192/kjicp.2019.24.2.52.

Prevalence and Risk Factors of Latent Tuberculosis Infection among Healthcare Workers

  • 1Department of Infectious Diseases, Ajou University School of Medicine, Suwon, Korea. yhwa1805@ajou.ac.kr
  • 2Infection Control Unit, Ajou University Medical Center, Suwon, Korea.


Due to occupational exposure, healthcare workers (HCW) face an increased risk of tuberculosis (TB) infection. This study was conducted to assess the prevalence and risk factors of latent tuberculosis infection (LTBI), and to estimate the cumulative risk of active TB among HCWs.
We conducted a cross-sectional study among HCWs in Ajou university medical center. A standard questionnaire was used for data collection, and LTBI was detected using the Interferon gamma-release assay (IGRA). The biographical information was collected from the electronic database. A computerized algorithm was used to evaluate the predicted cumulative risk of active TB in HCWs with LTBI.
Of a total of 1,407 HCWs, a positive IGRA result was detected in 138 HCWs. The prevalence of LTBI in HCWs was found to be 9.8% [95% confidence interval (CI) 8.2-11.4]. It was observed that the prevalence of LTBI increased with age (P value < 0.001). However, it was also observed that duration of the working periods in a TB-related department was not associated with LTBI (P value=0.369). According to the multivariate analysis, an increased risk of LTBI was observed among participants aged ≥ 50 years [odds ratio (OR) 7.522, 95% CI 3.56-15.89] and nursing assistants (OR 2.912, 95% CI 1.283-6.608). The median cumulative risk of active TB with LTBI was estimated to be 4.31% [interquartile range (IQR) 3.43-5.29], and 4.41% (IQR 3.14-5.29) in HCWs with and without work experience in TB-related department, respectively. No significant difference was observed between two groups (P value=0.715).
The prevalence of LTBI among HCWs may not be higher than that of individuals in other group facilities. It may be necessary to revise the treatment recommendations, which are classified based on the risk for LTBI associated with departments and locations of work.


Healthcare workers; IGRA; Latent tuberculosis infection; Risk factor; Tuberculosis

MeSH Terms

Academic Medical Centers
Cross-Sectional Studies
Data Collection
Delivery of Health Care*
Latent Tuberculosis*
Multivariate Analysis
Occupational Exposure
Risk Factors*


  • Fig. 1 Flow chart of the study. Abbreviations: See Table 1.

  • Fig. 2 Distribution of people by group.

  • Fig. 3 IGRA positive rate by work period in each risk group.

  • Fig. 4 IGRA positive rate according to age group.

  • Fig. 5 IGRA positive rate by occupation.

  • Fig. 6 Age, total work period and work period in TB related department according to occupation.

  • Fig. 7 Cumulative risk of active tuberculosis in healthcare workers with latent tuberculosis infection by age group.

  • Fig. 8 Treatment status by risk group.

Cited by  1 articles

TST (Tuberculin Skin Test)와 IGRA (Interferon-γ Release Assay)검사를 이용한 의료기관 종사자의 잠복결핵감염 유병률과 위험요인
Sin Jeong Kim, Eunjin Ha, Eun Suk Park, Jun Young Choi, Young Ae Kang
Korean J Healthc Assoc Infect Control Prev. 2020;25(1):46-53.    doi: 10.14192/kjicp.2020.25.1.46.


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