AFISE The Prevalence of Latent Tuberculosis Infection

The Prevalence of Latent Tuberculosis Infection estimated by QuantiFERON-TB Gold In Tube among BCG vaccinated children Aim To assess the prevalence of Latent TB Infection (LTBI) using an antigen-specific interferon-gamma assay, QuantiFERON test (QFT), in children exposed. Material and method A cross sectional study of prevalence was conducted from Sep 2006 to Jan 2007, in three schools from Constanta, Roma- nia. Results: Distribution by age and gender 250 200 150 Boys Girls 100 Total 50 0 6-8 yrs 8-10 yrs 10-12 yrs 12-14 yrs Total Results: The distribution of LTBI by age and gender 50 40 30 Girls Boys 20 Total 10 0 6-8 yrs 8-10 yrs 10-12 yrs 12-14 yrs Total Results 174 TST positive reactors (74%) 49 QFT tested (28.1%) 28 QuantiFERON positive reactors LTBI (57.1%) Conclusion   The prevalence of LTBI determined by TST is high among exposed children.   There is a strong discrepancy between positive TST and QFT in BCG vaccinated individuals. Clinical implications   QuantiFERON is more sensitive than TST, being able to identify the natural TB infection from a false positive TST reac- tion induced by the post BCG vaccine’s allergy.   It has greater specificity in revealing TB infection in BCG-vaccinated individuals. Authors: Oana Cristina Arghir¹,², Maria Ghelberg Talmacel³, Gheorghita Voicu² 1 School of Medicine, Ovidius University of Constanta, Romania 2 Clinical Pneumology Hospital, Constanta, Romania 3 Health Authority Laboratory Department, Constanta, Romania