Prevalence of Latent TB infection among healthcare workers identified by Interferon-Gamma Release Assay (IGRA) testing in Large Hospital
DOI:
https://doi.org/10.14456/10.14456/taj.2021.3Keywords:
Latent Tuberculosis Infection, Interferon-Gamma Release Assay, Health Care WorkerAbstract
This study was designed as a descriptive cross-sectional study, using 2 serial surveys to determine the prevalence of latent TB infection (LTBI) and related risk factors among health care workers (HCWs) in 24 large hospitals (Regional and Provincial hospitals) countrywide.
In the first survey, 911 HCWs participated in the study and their bloods were tested by Interferon-Gamma Release Assay: IGRA (QuantiFERON-TB Gold Plus). The result revealed that LTBI rate was 26.13% (238/911). The LTBI rate among male HCWs was significantly higher than female (35.24 vs 24.47%) (P<0.05). Infection rates among medical doctors and dentists, laboratory staffs, pharmacists and pharmacological staffs, radiology technicians and supporting administrative staffs were 36.00, 41.17, 42.86, 40.00, and 33.33% respectively. Risk factors that showed to be statistically significant difference in LTBI infection rates indicated by univariate analysis included duration of work which HCWs who worked longer than 2 years had higher rate of LTBI rate (32.16%) as compare to other group (P<0.01). The other significant factor was unit of work which HCWs worked in accident and emergency room (ER) had higher rate of LTBI (41.46%) (P<0.05).
Repeated IGRA test was conducted in the second survey at one year interval after the first survey. Out of 673 HCWs with negative result in the first survey, 517 (76.83%) participated in the survey. The result revealed an incidence of LTBI among HCWs (Converter) which was 6.96%. Nurse and practical nurse had highest risk of recent TB infection rate of 7.26 %. Incidence rates by working units in OPD, ER, and ICU were 13.33, 11.90 and 7.78% respectively.
It is recommended that measures on infection control should be strengthened, while regular health checkup and TB screening among HCWs should be done continuously.
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