3.1 Infection Control Principles

Why Infection Control Matters

Infection control makes up about 12% of the Minnesota CNA knowledge exam, and hand hygiene is the single most-tested skill across the entire test. It is also the skill most likely to appear on the NNAAP skills/clinical test administered in Minnesota by Headmaster, LLP — candidates are very commonly required to demonstrate handwashing as one of their randomly selected skills, and an error there can fail the whole skills portion.

Long-term care residents are often older, frail, and immunocompromised, so a nursing assistant who carries pathogens from one resident to another can cause a health-care-associated infection (HAI) that leads to hospitalization or death. A pathogen is a disease-causing microorganism — bacteria, viruses, fungi, or protozoa. The CNA's daily habits are the front line of defense for residents, coworkers, and the CNA personally.

Most infection-control questions on the written test are application questions: they describe a scenario and ask what you should do first or next. The correct answer almost always involves stopping transmission at the point where the CNA can control it — most often by performing hand hygiene or by choosing the right barrier.

The Chain of Infection

Infection spreads through a predictable six-link chain of infection. If you break any single link, the infection cannot pass to a new host. The exam expects you to recognize each link and the CNA action that breaks it.

The easiest and most reliable link for a CNA to break is the mode of transmission, which is exactly why hand hygiene is emphasized so heavily. Residents become susceptible hosts when they are weak, poorly nourished, have open skin, or have invasive devices such as a urinary catheter or feeding tube.

Medical Asepsis vs. Surgical Asepsis

Asepsis means the absence of disease-causing microorganisms. There are two levels, and the exam tests the difference:

• Medical asepsis (clean technique) reduces the number of pathogens and limits their spread. Examples include handwashing, wearing clean gloves, disinfecting a wheelchair between residents, and bagging dirty linen. This is what CNAs use for nearly all of their care.
• Surgical asepsis (sterile technique) removes all microorganisms, including bacterial spores, from an object or area. It is used for sterile dressing changes, urinary catheter insertion, and similar procedures performed by licensed nurses, not by nursing assistants in routine care.

Two clean-technique rules show up repeatedly on the test. First, always work from the cleanest area to the dirtiest — for example, wash a resident's face and eyes before washing the perineal (genital) area, and provide perineal care from front to back. Second, never shake linens, clothing, or bedding, because shaking sends microorganisms into the air where they can be inhaled or settle on clean surfaces. Hold linens away from your uniform and roll soiled surfaces toward the inside.

Standard Precautions

Standard precautions are the foundation of infection control. The rule is simple and absolute: treat the blood and all body fluids of every resident as if they are infectious, regardless of the resident's diagnosis. You do not need to know whether a resident has an infection in order to use them — you assume that everyone might.

Standard precautions include:

• Performing hand hygiene before and after every resident contact
• Wearing gloves when contact with blood, body fluids, mucous membranes, or non-intact skin is likely
• Wearing a gown, mask, or eye protection when splashing or spraying of fluids is possible
• Safely handling and disposing of sharps in a puncture-resistant container, and never recapping needles
• Cleaning and disinfecting reusable equipment between residents
• Following respiratory hygiene/cough etiquette — covering coughs and providing tissues

Body fluids covered by standard precautions include blood, urine, stool, vomit, saliva, wound drainage, and respiratory secretions. Sweat is the one exception that is not considered infectious — a classic exam fact. Standard precautions are used for all residents at all times; transmission-based precautions (covered in 3.2) are added when a specific germ requires extra barriers.

When and How to Perform Hand Hygiene

When to perform hand hygiene is the most-tested infection-control point. The WHO "Five Moments" summarize it: before touching a resident, before a clean/aseptic task, after body-fluid exposure risk, after touching a resident, and after touching the resident's surroundings. In practical CNA terms, perform hand hygiene:

• Before and after contact with any resident
• Before putting on gloves and after removing gloves (gloves are not a substitute for handwashing)
• After contact with blood, body fluids, or contaminated surfaces
• Before handling food or feeding a resident
• After using the restroom, coughing, sneezing, or blowing your nose
• At the start and end of your shift

Handwashing Steps (Soap and Water)

1. Turn on warm water and wet your hands and wrists, keeping fingertips pointed down so dirty water runs into the sink.
2. Apply soap and lather all surfaces — palms, backs, between fingers, and under nails — for at least 20 seconds.
3. Rinse from clean (wrists) to dirty (fingertips), fingertips pointing down.
4. Dry with a clean paper towel.
5. Use a dry paper towel to turn off the faucet so you do not recontaminate your hands.

Alcohol-based hand sanitizer is acceptable for routine decontamination of hands that are not visibly soiled, but you must use soap and water when hands are visibly soiled and after caring for a resident with Clostridioides difficile (C. diff), because alcohol does not kill C. diff spores — only the mechanical scrubbing of handwashing removes them.