Transmission-based precautions

The precaution follows the particle, not the illness

Precautions are not ranked by how dangerous a disease is. They are chosen by how far the organism travels once it leaves the client, and that is the only question worth asking.

• Airborne: droplet nuclei small enough to stay suspended and drift on air currents. Needs a negative-pressure room and a fit-tested respirator on everyone entering.
• Droplet: larger droplets that fall within a few feet. Needs a private room and a surgical mask on entry.
• Contact: spread by hands and surfaces. Needs a private room, gown and gloves for every entry, and dedicated equipment.

What goes where

• Airborne: tuberculosis, measles, varicella, disseminated herpes zoster.
• Droplet: influenza, pertussis, meningococcal disease, mumps, rubella.
• Contact: Clostridioides difficile, MRSA, VRE, scabies, RSV, norovirus.

Two get asked more than the rest. Varicella and disseminated zoster need airborne AND contact together, because the lesions are infectious as well as the air. And Clostridioides difficile is the one organism where alcohol gel fails: it forms spores that alcohol does not kill, so hands are washed with soap and running water and the room is cleaned with a chlorine-based agent.

Leaving the room

When a client on precautions has to travel, containment moves to the source. The client wears the mask, not the transporter, and the receiving department is told in advance so the client is taken straight through rather than left in a waiting area.

For contact precautions, the client's own hands are cleaned and any wound or drainage is covered before the journey. Nothing about the transport is a reason to delay a test the client needs.

Putting the equipment on and taking it off

1. Donning: hand hygiene, gown, mask or respirator, eye protection, gloves over the gown cuffs.
2. Doffing: gloves, then eye protection, then gown, then leave the room, then remove the respirator, then hand hygiene.

The order is not arbitrary. Gloves come off first because they are the most contaminated thing on you. The respirator comes off last and outside the room, because inside the room the air is exactly what it is protecting you from.