4.5 Transmission-Based Precautions

Transmission-Based Precautions

Transmission-Based Precautions are additional measures used when a resident has a known or suspected infection that ordinary Standard Precautions cannot contain. They are always used in addition to Standard Precautions, never instead of them. There are three categories — Contact, Droplet, and Airborne — chosen by how the organism travels. Matching the disease to the correct category and PPE is one of the most heavily tested topics on the CNA exam.

The Three Categories at a Glance

Contact Precautions

Used when an infection spreads by direct or indirect touch. Wear a gown and gloves for all contact with the resident or their environment, use dedicated equipment (a stethoscope and blood-pressure cuff that stay in the room), and limit transport. Common contact-precaution organisms:

• MRSA (Methicillin-resistant Staphylococcus aureus)
• VRE (Vancomycin-resistant Enterococcus)
• C. difficile (C. diff)
• Scabies and lice
• Draining wounds with significant discharge

Droplet Precautions

Used for organisms carried in large respiratory droplets that fall to the ground within roughly 6 feet. Wear a surgical mask when working within about 6 feet of the resident; if the resident must leave the room, they wear the mask. A private room is preferred, or residents with the same organism may be cohorted. Common droplet diseases:

• Influenza
• Pertussis (whooping cough)
• Mumps and Rubella
• Group A Streptococcus (strep throat in the acute phase)

Airborne Precautions

Used for organisms carried in tiny droplet nuclei (<5 microns) that stay suspended in the air for long periods and travel beyond the room. These require an Airborne Infection Isolation Room (AIIR) with negative pressure and 6–12 air changes per hour, the door kept closed, and a fit-tested N95 respirator (or a powered air-purifying respirator, PAPR). If transport is unavoidable, the resident wears a surgical mask. Memorize the airborne short list, often abbreviated "My Chicken Hez TB" for Measles, Chickenpox (varicella), disseminated Herpes zezter/shingles, and TB:

• Tuberculosis (TB)
• Measles (rubeola)
• Chickenpox (varicella) and disseminated shingles (herpes zoster)

High-Yield Special Cases

CNA Responsibilities in Isolation

Before entering, read the precaution sign on the door so you know what to wear. Don PPE in the correct sequence before entry, provide care following all requirements, doff PPE in the room or anteroom in the correct order, and perform hand hygiene immediately after leaving. When private rooms are scarce, residents with the same organism may be cohorted (grouped) — but you must still change gloves and perform hand hygiene between each resident to avoid cross-contamination.

Protecting Psychological Well-Being

Isolation is medically necessary but emotionally hard. Residents in isolation are visited less often, may feel "dirty" or contagious, and are at higher risk of loneliness and depression. The CNA should visit as often as safely possible, explain in plain language why the precautions exist, keep the call light within reach, spend a few unhurried moments providing emotional support, and report signs of withdrawal or depression to the nurse. Infection control and compassionate care are not in conflict — both are part of the job.

How to Choose the Right Category on the Exam

The fastest way to answer a precaution question is to ask how the organism spreads, then map it to the category and PPE. If it spreads by touch (skin, wounds, stool, fomites), the answer is Contact — gown and gloves. If it spreads by coughing or sneezing in large droplets that fall within a few feet, the answer is Droplet — surgical mask. If it spreads by tiny particles that float and linger in the air, the answer is Airborne — N95 and a negative-pressure room. Build a small mental list of the airborne and droplet diseases (they are short and finite), and assume that anything else transmissible is Contact.

A classic trap pairs a disease with the wrong PPE — offering a surgical mask for tuberculosis (wrong; TB needs an N95) or an N95 for influenza (overkill; flu is droplet). Anchor on the transmission route, not on how "serious" the disease sounds.

Combined and Layered Precautions

Some organisms need more than one category at once. COVID-19 is managed with Droplet plus Contact precautions for routine care, escalating to Airborne (N95 or PAPR in a negative-pressure room) whenever an aerosol-generating procedure such as suctioning or nebulizer treatment is performed. Disseminated shingles requires both Airborne and Contact precautions. Whenever categories are layered, you apply all the PPE and room requirements of each — and Standard Precautions always remain the base layer underneath.

When in doubt about which precautions are in effect, the safe action is to read the door sign and ask the nurse before entering, never to guess.