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

Patimaporn Chanpho,Naesinee Chaiear,Supot Kamsa-Ard

doi:10.3390/ijerph17186876

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.

Highlights

Tuberculosis is a contagious disease caused by the bacteria Mycobacterium tuberculosis
Health care workers (HCWs) who reported the absence of a Bacille Calmette-Guérin (BCG) scar had a statistically significant association with Latent tuberculosis infection (LTBI), whereas other factors including close contact with TB were not significantly associated with LTBI
HCWs who performed aerosol-generating procedures (AGPs) and were absent a BCG scar had a significant association with LTBI, while other factors played a less critical role

Summary

Introduction

Tuberculosis is a contagious disease caused by the bacteria Mycobacterium tuberculosis. The infection is transmitted person-to-person through aerosols that access the body via the respiratory system [1,2,3]. Latent tuberculosis infection (LTBI) is a state of persistent immune response to stimulation by Mycobacterium tuberculosis antigens without evidence of clinically-manifested active TB. A person has LTBI if they are infected with the TB mycobacteria but do not have signs of active TB disease. Res. Public Health 2020, 17, 6876; doi:10.3390/ijerph17186876 www.mdpi.com/journal/ijerph

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