Factors Associated with Latent Tuberculosis Infection among the Hospital Employees in a Tertiary Hospital of Northeastern Thailand

Abstract

Latent tuberculosis infection (LTBI) can develop into tuberculosis (TB). The WHO requires the discovery and management of LTBI among high-risk groups. Health care workers (HCWs) constitute a high-risk group. Factors associated with LTBI among HCWs in Thailand need further study. The current study aimed to explore the factors related to LTBI among Thai HCWs. A hospital-based, matched case-control study was conducted. All cases and controls were HCWs at a tertiary hospital in northeastern Thailand. Between 2017 and 2019, a total of 85 cases of interferon-γ release assays (IGRAs)-proven LTBI, and 170 control subjects were selected from a hospital (two controls per case). The two recruited controls were individually matched with LTBI cases by sex and age (±5 years). Secondary data were obtained from the occupational health and safety office. Case HCWs had a higher proportion of significant factors than control HCWs (i.e., working closely with pulmonary TB—94.1% vs. 88.8%, and working in the area of aerosol-generating procedures (AGPs) 81.2% vs. 69.4%). The bivariate conditional logistic regression showed that the occurrence of LTBI in HCWs was statistically significant (p-value < 0.05), particularly with respect to: workplaces of AGPs (crude OR = 1.90, 95% CI: 1.01–3.58, p = 0.041); among HCWs performing AGPs (crude OR = 2.04, 95% CI: 1.20, 3.48, p = 0.007); and, absent Bacille Calmette-Guérin (BCG) scar (crude OR = 2.59, 95% CI: 1.50–4.47, p = 0.001). Based on the multivariable conditional logistics analysis, HCWs who performed AGPs while contacting TB cases had a statistically significant association with LTBI (adjusted OR = 1.82, 95% CI: 1.04–3.20, p = 0.035). HCWs who reported the absence of a BCG scar had a statistically significant association with LTBI (adjusted OR = 2.49, 95% CI: 1.65–5.36, p = 0.001), whereas other factors including close contact with TB (adjusted OR = 2.44, 95% CI: 0.74, 8.09, p = 0.123) were not significantly associated with LTBI. In conclusion, HCWs who performed AGPs and were absent a BCG scar had a significant association with LTBI, while other factors played a less critical role.

Prevalence, Risk Factors, and Result Features in the Detection of Latent Tuberculosis Infection in Thai Healthcare Workers Using QuantiFERON-TB Gold Plus

“…Furthermore, strict exposure areas, rapid active case-finding, and early treatment of active TB could be important strategies to prevent or reduce TB infection among HCWs. Besides the working department, it should be noted that no significant relationship was found between the type of job and LTBI, contrary to previous studies reporting a significant risk for LTBI associated with working in critical hospital areas [28] or critical jobs that highly generate or directly expose to MTB aerosols [29]. We explain that most HCWs who work in high-risk procedure jobs are more likely to take stringent precautions to avoid infection, in contrast to those in low-risk jobs.…”

Validity and Reliability of Self-Assessment Tool for Risk Prioritization Following Exposure to Tuberculosis in a Hospital Setting

“…AGPs play a major role in respiratory infection [ 21 , 22 ]. Chanpho et al [ 23 ] postulated that the HWs who perform AGPs had a significant association with LTBI (OR = 2.04, with 95% CI: 1.20, 3.48, p = 0.007). Although the result of contact activity factors had a Kappa agreement for MSA than PSA (Kappa 0.75 vs. Kappa 0.84), both MSA and PSA passed the agreement criteria (Kappa ≥ 0.60).…”

What Tool for Diagnosis of Latent Tuberculosis Infection in Developing Country with Tuberculosis High Burden: Interferon Gamma Release Assays <i>versus</i> Tuberculin Skin Test in Burkina Faso

“…Latent tuberculosis infection (LTBI) is a Mycobacterium tuberculosis complex infection status without evidence of clinical or radiological symptoms or signs of active tuberculosis and it is non-transmissible [1] [2]. A third of the world's population has been exposed to tuberculosis (TB), estimating 1.7 billion LTBI cases among the world's population [3]. Most of these cases remain undiagnosed and therefore constitute a major challenge in the control of tuberculosis [1].…”