A nurse is preparing to enter the isolation unit for a patient with suspected Ebola virus disease. Which personal protective equipment (PPE) sequence demonstrates the correct donning procedure for enhanced contact precautions?

The correct donning sequence (hand hygiene → gown → mask/respirator → eye protection → gloves → boot covers → hand hygiene) follows CDC/WHO guidelines to build multiple protective barriers. Other options disrupt this systematic approach, increasing contamination risk.

Correct Answer and Rationale

The correct sequence is Hand hygiene → gown → mask/respirator → eye protection → gloves → boot covers → perform hand hygiene. This order is critical for maintaining the integrity of the barrier and preventing self-contamination during the donning process for enhanced contact and droplet precautions, such as those required for suspected Ebola virus disease (EVD).

In-Depth Analysis of the Donning Sequence

The rationale for this specific sequence is rooted in the principles of infection control and the physical design of personal protective equipment (PPE). The goal is to create a continuous, overlapping barrier from the inside out, ensuring that each subsequent piece of equipment secures the one beneath it.

1. Hand Hygiene (Initial): The process begins with hand hygiene to decontaminate the hands, which are the primary vector for pathogen transmission. This step ensures that the hands are clean before touching any PPE, preventing the transfer of organisms from the hands to the equipment and subsequently to the patient or environment. A study on healthcare worker preparedness for EVD outbreaks highlighted that critical gaps in infection control practices, including hand hygiene, directly contributed to occupational exposure, with healthcare workers accounting for 13.4% of cases in one outbreak ^[3].

2. Gown: The gown is donned first because it forms the main body barrier. It must be fully secured at the neck and waist before other equipment is added. This prevents the gown from slipping or becoming contaminated during the rest of the donning process.

3. Mask or Respirator (e.g., N95): The mask or respirator is placed next to secure the airway. It must be fitted and sealed before the face shield or goggles, as the eye protection must sit over the top edge of the mask to create a proper seal and prevent gaps. A scoping review on AI-assisted PPE training confirms that errors in the sequence of donning and doffing are a significant contributor to self-contamination among healthcare workers .

4. Eye Protection (Goggles or Face Shield): Eye protection is applied after the mask to ensure it overlaps the upper edge of the mask, creating a seamless barrier against splashes and droplets. If eye protection were donned first, it would be impossible to achieve a proper seal with the mask underneath it.

5. Gloves: Gloves are donned last among the upper-body equipment. Their purpose is to cover the cuff of the gown, creating a continuous barrier from the forearm to the hand. If gloves were donned earlier, the gown's sleeves could ride up during application, exposing the wrist. A simulation-based study on PPE proficiency found that deliberate practice and coaching on this specific overlapping technique significantly reduced errors in competency .

6. Boot Covers: Boot covers are applied last to cover the footwear and the lower pant legs, completing the full-body barrier. They are donned after the gown to ensure they can be pulled up over the gown's lower edge.

7. Hand Hygiene (Final): A final hand hygiene step is performed after all PPE is in place to decontaminate the gloved hands, acknowledging that the outer surface of the gloves may have become contaminated during the donning process itself.

Why the Other Options are Incorrect

- Option 2 (Gown → hand hygiene → mask...): Performing hand hygiene after touching the gown is a critical error. The hands are considered contaminated after handling the gown's exterior, and immediately touching the mask or face would transfer pathogens to a high-risk mucosal area. This sequence directly violates the principle of "clean to dirty" workflow.
- Option 3 (Hand hygiene → mask → gown → gloves → eye protection...): Donning gloves before eye protection is a major sequence error. With gloves on, the dexterity needed to properly position and secure eye protection or a face shield is compromised, and the contaminated gloves could touch the face during the process. A systematic review on extended reality training for infection control emphasizes that such procedural errors are common and can be effectively mitigated through structured, step-by-step training interventions .
- Option 4 (Hand hygiene → eye protection → gown → mask...): Donning eye protection before the mask prevents the creation of a proper seal. The mask must be on first so the eye protection can overlap it. Furthermore, donning the gown after the mask and eye protection risks contaminating these facial barriers with the gown's material during application. The correct sequence always builds the barrier from the body outward and from the top down, ensuring each layer protects the one beneath it.