Usefulness of the QuantiFERON-TB-Gold in tube in a population at risk of bovine tubercular infection

Mycobacterium bovis is the causative agent of bovine tuberculosis in cattle and it infects a large number of domestic and wild mammal species. This microorganism constitutes an important risk for human health, since it can cause zoonosis. M. bovis can be transmitted to humans by drinking contaminated milk or unpasteurized fresh cheese or other animal derived products. Trans-mission through direct contact or air is possible, especially in subjects like veterinarians and breeders who are directly exposed to infected animals. Protein purified derivative (PPD) assay, despite its several limitations [6], was largely used as gold standard for indirect tubercular diagnosis both in cattle and humans. Interferon-gamma release assays (IGRAs) have been recently developed for the diagnosis of tuberculosis (TB) infection. QuantiFERON-TB-Gold (QFT-G) is one of these new tests. It is an in vitro immunological assay, which measures the Interferon-gamma (IFN-g) released by T cells sensitised with the M. tuberculosis complex (i.e. M. tuberculosis, M. bovis) specific antigens ESAT-6, CFP-10 and TB7 .