title: Prevalence of Latent Tuberculosis among Health Care Workers in High Burden Countries: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Tuberculosis is one of the leading causes of death worldwide. Twenty-two high burden countries contributed to the majority of worldwide tuberculosis cases in 2015. Health care workers are at high risk of acquiring tuberculosis through occupational exposure.
  
  
  OBJECTIVE
  To estimate the prevalence of latent tuberculosis infection (LTBI) among health care workers in high burden countries.
  
  
  METHODS
  Databases including MEDLINE (Ovid), EMBASE (Ovid), CINAHL (Ovid) and ISI Web of Science (Thompson-Reuters), and grey literature were searched for English language records on relevant medical subject headings (MeSH) terms of LTBI and health care providers. Literature was systematically reviewed using EPPI-Reviewer4 software. Prevalence and incidence of LTBI and 95% confidence intervals (CI) were reported. Pooled prevalence of LTBI and 95% CI were calculated using random-effects meta-analysis models and heterogeneity was assessed using I2 statistics. Sub-group analysis was conducted to assess the cause of heterogeneity.
  
  
  RESULTS
  A total of 990 records were identified. Of those, 18 studies from only 7 high burden countries representing 10,078 subjects were included. Tuberculin skin test results were available for 9,545 participants. The pooled prevalence of LTBI was 47% (95% CI 34% to 60%, I2 = 99.6%). In subgroup analyses according to the country of the study, the pooled prevalence of LTBI was lowest in Brazil (37%) and highest in South Africa (64%). The pooled prevalence of LTBI among medical and nursing students was 26% (95% CI 6% to 46%, I2 = 99.3%) while the prevalence among all types of health care workers was 57% (95% CI 44% to 70%, I2 = 99.1%). Incidence of LTBI was available for health care workers in four countries. The cumulative incidence ranged from 2.8% in Brazilian medical students to 38% among all types of health care workers in South Africa.
  
  
  CONCLUSIONS
  The findings of this study suggest that there is a high burden of LTBI among health care workers in high burden countries. Adequate infection control measures are warranted to prevent and control transmission in health care settings.
authors.affiliation: Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
authors.forename: Sharifa
authors.initials: S
authors.lastname: Nasreen
authors.affiliation: HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV Surveillance, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran.|Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Shokoohi
authors.affiliation: Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.|Department of Ophthalmology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
authors.forename: Monali S
authors.initials: MS
authors.lastname: Malvankar-Mehta
mesh_terms: D017281:Cost of Illness; D006282:Health Personnel / Q000706:statistics & numerical data*; D006801:Humans; D055985:Latent Tuberculosis / Q000191:economics / Q000453:epidemiology*