Global Tuberculosis

In terms of diagnostics, there has been a well-established armament of procedures. Pulmonary tuberculosis is generally suspected on the basis of chest x-rays taken while evaluating respiratory symptoms such as a cough lasting more than three weeks, hemoptysis (blood in the sputum; coughing up blood), chest pain, dyspnea, any unexplained illness and/or a positive tuberculin skin test. Skin testing is perhaps the widest used diagnostic test for tuberculosis. The Mantoux test (Mantoux Screening Test, Tuberculin Sensitivity Test, Pirquet test, or PPD test --- for Purified Protein Derivative) is a diagnostic tool for tuberculosis.

The Mantoux test is used in the United States and is endorsed by the American Thoracic Society and Centers for Disease Control and Prevention (CDC). Multiple puncture tests such as the Tine test are not recommended. The Mantoux test is one of the two major tuberculin skin tests for tuberculosis used in the world.

As a replacement for the Mantoux test, several other tests are being developed. QuantiFERON®-TB Gold, manufactured by Cellestis Limited (Carnegie, Victoria, Australia) is a blood test that measures the patient’s immune reactivity to the M. tuberculosis and is useful for initial and serial testing of persons with an increased risk of latent or active tuberculosis infection. Guidelines for the use of QuantiFERON-®TB Gold were released by the CDC in December of 2005. QuantiFERON®-TB Gold is FDA approved in the United States; has CE Mark approval in Europe; and has been approved by the MHLW in Japan. Sputum smears and cultures should be done for acid-fast bacilli if the patient is producing sputum. The preferred method for this is fluorescence microscopy (auramine-rhodamine staining), which is more sensitive than conventional Ziehl- Neelsen staining.