A nurse is caring for multiple patients with different infectious diseases. Which patient requires airborne precautions in addition to standard precautions?

Airborne precautions are required for diseases transmitted via small airborne droplet nuclei (≤5 μm) that remain suspended in air. Active pulmonary tuberculosis requires airborne precautions due to transmission via these nuclei. MRSA, C. difficile, and influenza require contact or droplet precautions, not airborne.

Understanding Transmission-Based Precautions
The NCLEX-RN frequently tests your ability to match a specific infectious disease with the correct category of transmission-based precautions. These precautions are always implemented in addition to standard precautions, which are used for every patient regardless of their diagnosis. The core concept is understanding the portal of exit from the infected host and the mechanism of transmission to a susceptible host.

Analysis of the Correct Answer
Active pulmonary tuberculosis is the classic exemplar for airborne precautions. Mycobacterium tuberculosis is carried in droplet nuclei—tiny infectious particles measuring 5 microns or less that are expelled when the patient coughs, sneezes, or during aerosol-generating procedures. These particles can remain suspended in the air for hours and travel long distances via air currents. The updated AORN guideline explicitly outlines strategies for airborne precautions, which include placing the patient in a negative-pressure airborne infection isolation room (AIIR) and using a fit-tested N95 respirator or powered air-purifying respirator (PAPR) ^[1]. The systematic review on Nipah virus similarly reinforces that for pathogens with demonstrated airborne potential, stringent respiratory protection and environmental controls are critical to protect healthcare workers ^[2]. The RCT protocol for TB preventive treatment highlights the elevated risk of acquisition among close contacts, underscoring why immediate isolation with airborne precautions is non-negotiable for an active pulmonary case .

Analysis of Incorrect Options
- Option 1: MRSA wound infection requires contact precautions. The organism is transmitted by direct or indirect contact with the infected wound or contaminated surfaces. A gown and gloves are essential. Airborne precautions are not indicated because MRSA is not suspended in the air in droplet nuclei.
- Option 3: Clostridium difficile-associated diarrhea also requires contact precautions, with a critical emphasis on hand hygiene with soap and water, as alcohol-based hand rubs are not effective against C. difficile spores. Transmission occurs via the fecal-oral route through contact with contaminated surfaces.
- Option 4: Influenza A requires droplet precautions. The virus is transmitted via large respiratory droplets (> 5 microns) that travel short distances (typically 3 to 6 feet) when the patient coughs or sneezes. A standard surgical mask is the appropriate respiratory protection, not an N95 respirator, unless an aerosol-generating procedure is being performed.

Clinical Integration for Practice
The CSPS validation study reminds us that consistent compliance with standard precautions is the foundation upon which all transmission-based precautions are built . When assessing a patient with a suspected or confirmed airborne illness, your clinical judgment must immediately prioritize the placement of a surgical mask on the patient during transport and ensuring they are placed in a negative-pressure room. For the NCLEX, remember that the "airborne" trio most commonly tested includes Tuberculosis, Measles (Rubeola), and Varicella (Chickenpox)/Disseminated Herpes Zoster. The mode of transmission dictates the precaution type, and for pulmonary TB, the generation of airborne droplet nuclei makes the N95 respirator and AIIR the only correct choice.