Abstract
Background: Health care workers (HCWs) treating patients with tuberculosis (TB) are at risk of becoming infected. Hence periodical screening of HCWs is a part of TB control programs in low incidence countries. Evidence of the utility of Interferon gamma release assays (IGRAs) in diagnosing latent TB is growing.
Aim: The aim of the study was to estimate the prevalence of latent tuberculosis and the within subject variability of IGRA among health care workers with known exposure to TB at work in a TB low incidence country.
Methods: Employees working at the pulmonary ward and as radiographers in Gentofte Hospital in Copenhagen (approximately 150 treated TB patients/year) were invited to participate. They completed a questionnaire and blood samples for IGRA-testing (QuantiFERON®, cellestis) were drawn twice with an interval of two weeks.
Results: 130 persons participated. Eight (6,2%) had two positive quantiferon tests and of these four had no history of TB exposure other than at work. One had been traveling, but not living or working, in TB high incidence countries. One had previously been treated for pulmonary TB, which was presumed work-related. Two of them had been living in TB high incidence countries. Two persons, who had been living in Tb-high incidence countries, had one positive and one inconclusive test. Two persons (1,5%) who initially had negative tests, was tested positive after two weeks. Conclusion: HCWs do have a occupational risk of becoming latently infected with TB. Whether and under which circumstances IGRA tests can be used to screen healthcare workers for latent TB awaits further studies on IGRAs used for serial testing.
- © 2013 ERS