Symptoms of TB include coughing that lasts for more than three weeks, coughing with blood, chest pain, difficulties in breathing, weight loss for no apparent reason, chronic fatigue, fever, night sweats, chills, and appetite loss.
If TB is suspected, the doctor may require the patient to undergo a complete medical evaluation. Tests for TB infection includes the following: skin test (Mantoux test) where PPD tuberculin is injected under the skin of the inside forearm. chest X-ray or CT scan of the lungs to detect granuloma or cavities. culture tests of sputum. biopsy of the affected tissue. bronchoscopy. thoracentesis. or microscopic-observation-drug susceptibility (MODS) assay to detect bacteria presence in sputum and identify drug resistance of TB bacteria strain. The latter tests are done when skin and blood tests are positive.
Nahid et al promoted the more advanced tools for detecting tuberculosis (2006). Two commercial kits are available for detecting latent TB - the QuantiFERON-TB Gold test and the T SPOT-TB test – which “detect cellular immune response by measuring IFN-γ released by T cells after stimulation by Mycobacterium tuberculosis antigens”. Another recent advance in diagnosing TB is the nuclear acid amplification (NAA) which detects genes associated with drug resistance. Nahid et al recommend these more recent diagnostic tools because of their greater specificity, accuracy, and reliability (2006). MODS trial is still the predominant testing tool in developing countries while NAA is available in developed countries.