Interferon gamma release assay for identification of latent Mycobacterium tuberculosis infection in HIV hospital staff – The association between occupational and non-occupational exposure

Background: Tuberculosis remains an important healthcare problem in Poland. At the same time tuberculosis is the most common AIDS defining condition diagnosed in HIV-positive persons in Poland. Therefore, we have investigated the prevalence of latent TB infection among healthcare staff of HIV hospital.Material and methods: The interferon gamma release assay (IGRA) was offered to all hospital staff. Participants filled in a self-report questionnaire on demographics, work position, time of employment, occupational and non-occupational contact with TB. In statistical analysis nonparametric tests were used for group comparison. A multivariable logistic regression model was developed including all variables with p < 0.1 in univariable models.Results: Overall 86 (20.9%) of 411 HCW participated in the study. Those with positive IGRA test (12.8%) were older, more likely to undergo TB treatment in the past or having a history of home TB contact. There was no statistical difference between the groups in duration of employment, occupational exposure or its frequency. Factors remaining statistically associated with positive IGRA test was age (OR 1.11, [95% CI: 1.00-1.22]) and home TB contact (OR 36.9, [95% CI: 1.97-688.8]), whereas duration of employment (OR 0.98, [95% CI: 0.89-1.09]) and active TB in the past (OR 0.99, [95% CI: 0.04-25.3]) revealed to be non-significant.Conclusion: The prevalence of latent TB infection among healthcare staff was slightly higher than the one reported in other high income countries. However the risk of acquiring tuberculosis among healthcare workers of HIV hospital was mainly linked to non-occupational exposures. IGRA screening may serve as an important tool in limiting tuberculosis transmission. (C) 2013 Polish AIDS Research Society. Published by Elsevier Urban & Partner Sp. zo.o. All rights reserved.