Final answer:
For potential tuberculosis, BSL-3 is the correct biosafety level needed for handling specimens due to the contagious nature of Mycobacterium tuberculosis. Protective gear and specific safety cabinets are mandatory for handling specimens. The Mantoux tuberculin skin test, while commonly used for screening, can yield false-positive results if the patient has previously received the BCG vaccine.
Step-by-step explanation:
For patients with potential tuberculosis (TB), the most appropriate biosafety level (BSL) for handling specimens is BSL-3. Health-care workers dealing with TB must take rigorous precautions to avoid infection, including the use of protective equipment and a class II biological safety cabinet. The pathogen responsible, Mycobacterium tuberculosis, is identified using the Ziehl-Neelsen staining technique to detect acid-fast bacilli in a sputum smear. Though this method is useful, it is not entirely definitive for diagnosis, and other clinical methods such as a chest radiograph may be necessary for confirmation.
Regarding the tuberculosis skin test, the Mantoux tuberculin skin test is commonly employed to screen for TB exposure. However, a history of BCG (bacillus Calmette-Guérin) vaccination can lead to false-positive results. Therefore, additional diagnostic methods, including chest radiographs, might be necessary to confirm TB infection. It's crucial to understand that a positive Mantoux test indicates a type IV hypersensitivity reaction, which could be due to an active infection or a past exposure that has been either cleared or gone latent.