Nontuberculous mycobacteria can be very difficult to diagnose. Unfortunately, this difficulty sometimes delays initial diagnosis until after the patient has had recurrent infections.

This may make treatment more difficult because prior use of single drug therapy may have created some drug resistance. Also, recurrent infections and associated inflammation may have resulted in additional damage to the respiratory system.

The diagnosis of NTM involves the following:

1. Sputum culture - Sputum is cultured for acid fast bacilli (AFB), which is the basic test to identify mycobacteria. For accurate identification of the specific species (type of NTM disease), and drug sensitivities, testing should be done at a highly specialized laboratory. These specialized labs can tell your doctor which drugs will work (drug sensitivity) and which ones will not work (drug resistance) on the strain of NTM that you have. Equally important is the need to determine which combination of drugs must be used in order to minimize risk of developing drug resistance, a common problem when NTM infections are treated with single drug therapies.

2. Chest CT (computed tomography) - Chest x-rays provide rudimentary identification of infiltrates in the lungs. A CT scan provides the doctor with a detailed look at the extent and location of disease and is an important diagnostic tool.

3. Medical History - Knowing what illnesses you have had, including childhood illnesses, may provide your doctor with additional understanding of why certain underlying lung conditions exist.