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.