Comparison of tuberculin skin test and quantifon tb gold test in diagnosis of latent infection in hospital staff

Throughout human history, tuberculosis have had an important place in infectious diseases. In recent years despite a growing global effort, the number of new tuberculosis cases are rapidly increasing. Tuberculin skin test is the first known immunological diagnostic tool in tuberculosis. However, tuberculin skin test has limitations in diagnosis with some aspects. As a result of studies in recent years, compared to the tuberculin skin test, studies which more specific results are made. In our study, we aimed to investigate tuberculin skin test and Quantiferon TB Gold test in the diagnosis of latent tuberculosis infection in hospital employees and to compare the efficacy of these two tests. In our study, 70 volunteer health workers were taken from Fırat University Hospital employees. A questionnaire form was created for all health care workers who enrolled in the study. Tuberculin skin testing initially be questioned and was recorded in the form. Number of Bacille Calmette-Guerin scar from the study participants was recorded and chest X-rays were taken. First, blood samples have been taken to special tubes that surface coated with antigen and produced for Quantiferon kits, then tuberculin skin tests were applied to employees. There wasn't a statistically significant correlation between enduration diameter of Quantiferon TB Gold test and tuberculin skin test in a positive direction at % 18. (Spearman correlation coefficient 0.433, p <0.01). In our study, we evaluated tuberculin skin tests with separating groups as over 0-4 mm, 5-14 mm, 15 mm. Tuberculin skin test which was over 15 mm, Quantiferon TB Gold positive rate has been found 18% (p <0.01). So, this shows us there isn't an association between induration diameter of tuberculin skin test and positive QuantiFERON TB Gold test. In communities where re-immunization has been applied acoording to routine Bacille Calmette-Guerin vaccination and tuberculin skin test results like our country, we might suggest Quantiferon TB Gold test as an alternative tuberculin skin test for mass screening like hospital staff taking into consideration disadvantages and advantages of this test as easy of sample collection, obtain results in a short time and to be encountered once the patient. For use Quantiferon TB Gold test in clinical practice and to reveal cases which have higher possibility of creating active disease, it should be standardized, cost reduction and compared long term studies should be done with tuberculin skin test as positive control. Key Words:Tuberculin skin testing, QuantiFERON-TB Gold-inTube, latent tuberculosis infection, tuberculosis.