Prevalence and Risk Factors of Latent Tuberculosis Infection among Healthcare Workers in Rajavithi Hospital, Bangkok

Abstract

Healthcare workers (HCWs), who are close contacts with TB patients, have a high risk for latent
tuberculosis infection (LTBI); and approximately 10% of infected person will eventually develop TB
disease. The objective of this study was to determine the prevalence and risk factors associated with
LTBI among HCWs in Rajavithi Hospital, Bangkok. It was conducted as a cross-sectional study. Data
were collected from 270 HCWs in the hospital during September 2020 to July 2021 by questionnaire
and blood sampling test for the QuantiFERON-TB Gold Plus (QFT-Plus) assay. The univariate and
multivariate analysis were used for statistical analyses and p<0.05 was considered for statistically
significance. It was found that 60 HCWs were positive QFT-Plus assay, and the prevalence of latent
tuberculosis infection was 22.22%. Univariate analysis showed factors significantly associated with a
positive QFT-Plus assay were: age 30 years and older (OR=6.05; 95%CI=2.91-12.58), other healthcare
professional than physician and nurse (OR=1.94; 95%CI=1.09-3.47), working duration time over
10 years (OR=4.64; 95%CI=2.53–8.54), low risk workplace (OR=2.54; 95%CI=1.35-4.77) and
handling over 6 samples/cases of TB specimens/patients per week (OR=2.28; 95%CI=1.06-4.88).
In multivariate analysis, age 30 years and over was associated with an increased risk of a positive
QFT-Plus (aOR=5.41; 95%CI=2.51–11.67). In conclusion, this study found prevalence rate of latent
tuberculosis infection in HCWs by QFT-Plus assay was 22.22%. Aged 30 years and older was found
to be an important risk factor associated with latent tuberculosis infection. This information should be
considered for implement IGRAs test in the annual health checkup program for screening and any healthcare
workers who tested positive should receive treatment and monitoring.