Sammanfattning
The tuberculin skin-test with its disadvantages has until recently been the only way of diagnosing latent tuberculosis. During the last decade interferon-gamma release assays detecting reactivity against ESAT-6/CFP-10 have been developed to provide a more specific diagnosis. They have been employed in many studies in different countries but until now , no study has been reported from Sweden.
We used the Quantiferon-TB-GOLD (Cellestis) test to examine 110 health care workers who had been exposed to tuberculosis to a slight or moderate degree.
Four of the staff had a positive test and of these two were judged as true positive. It was, however, not possible to ascertain that the positive tests were related to the present exposure. Forty four persons were tested with the tuberculin test. Of these, 13 had a PPD > 10mm, but none of them displayed a positive Quantiferon test.
Considering the not very intense exposure to contagious tuberculosis among those examined and the low prevalence of latent tuberculosis in Sweden, the results seem reasonable. The interferon-gamma release assays appear to have the potential of becoming a valuable tool for examining contacts of cases with newly diagnosed tuberculosis.