Rapid detection of mycobacterium tuberculosis infection in patients and contacts

: To reach a sensitive and rapid method for the laboratory diagnosis of active TB disease in patients and latent TB infection in household contacts and healthy community controls.Study design: Comparative cross sectional study.Subjects and methods: We recruited 86 subjects divided into 3 groups: Thirty six patients with suspected active TB (Twenty four suspected pulmonary TB cases and 12 suspected extrapulmonary TB cases), 28 household contacts of confirmed pulmonary TB patients and 22 healthy community controls. Methods: For diagnosis of active tuberculosis the following tests were evaluated: Ziehl-Neelsen (Z-N) staining and culture on Löwnestein-Jensen (L-J), tuberculin skin test (TST), nested polymerase chain reaction (PCR) assay on separated peripheral blood mononuclear cells (PBMCs), antibody detection by immunochromatographic test (ICT), and IFNγ assay by Quantiferon TB Gold In-tube method. For diagnosis of latent tuberculosis the following tests were evaluated: TST and Quantiferon TB Gold (In-tube method).