Final answer:
For a patient suspected of TB on airborne precautions, a Mantoux tuberculin skin test and chest radiographs are commonly ordered to screen for and confirm TB infection. Microscopic examination of respiratory fluid samples is also used to detect Mycobacterium tuberculosis directly.
Step-by-step explanation:
If a patient is suspected of having tuberculosis (TB) and is placed on airborne precautions, several tests can be ordered. The initial screening test often used is the Mantoux tuberculin skin test, where a small amount of tuberculin protein derivative is injected under the skin. After 48-72 hours, the injection site is checked for a reaction, such as redness, swelling, or hardness, which indicates exposure to TB. However, chest radiographs are typically required to confirm actual infection, as they can detect changes in the lungs associated with TB, such as the Ghon complex. In addition to radiology, microscopic examination of respiratory fluid samples using the Ziehl-Neelsen staining technique to look for acid-fast bacilli is another diagnostic method. This smear can reveal the presence of Mycobacterium tuberculosis, the bacteria that causes TB.