3.2 Infection Control and Precautions

The Chain of Infection

Infection spreads through six linked steps called the chain of infection. Breaking any one link stops the spread, and the nurse aide's everyday habits - especially hand hygiene - break the chain at the mode of transmission, the easiest link to attack.

1. Causative agent - the germ (bacteria, virus, fungus, or protozoan).
2. Reservoir - where the germ lives and multiplies (a person, equipment, food, water).
3. Portal of exit - how it leaves the reservoir (coughing, blood, urine, stool, wound drainage).
4. Mode of transmission - how it travels (contaminated hands, droplets, air, equipment).
5. Portal of entry - how it enters a new host (broken skin, mouth, nose, eyes, catheter).
6. Susceptible host - a person at risk (elderly, weakened, or chronically ill residents).

Residents in long-term care are highly susceptible hosts because aging weakens the immune system, so prevention is the aide's constant job. Microorganisms that cause disease are called pathogens; a healthcare-associated infection (HAI) is one a resident catches in the facility, and many are preventable with good technique.

Hand Hygiene: The Most Important Skill

Proper hand hygiene is the single most effective way to prevent infection, and hand washing is always one of the five skills on the Georgia NNAAP skills evaluation, so you must perform every step perfectly. Wash your hands before and after every resident contact, after removing gloves, after touching anything contaminated, before handling food, and after using the restroom.

The hand-washing sequence (memorize the order):

1. Turn on water and wet hands with fingertips pointing down.
2. Apply soap and rub all surfaces - palms, backs, between fingers, and under nails - for at least 20 seconds.
3. Keep hands lower than the elbows so dirty water runs off the fingertips, not back up the arms.
4. Rinse thoroughly, fingertips down.
5. Dry with a clean paper towel.
6. Turn off the faucet using a clean, dry paper towel so you do not re-contaminate clean hands.

Alcohol-based hand sanitizer is acceptable when hands are not visibly soiled, but use soap and water when hands are visibly dirty and always after caring for a resident with Clostridioides difficile (C. diff) because the spores resist sanitizer. This soap-vs-gel distinction is a classic exam trap.

Standard Precautions and PPE

Standard precautions are used with every resident, every time, no matter the diagnosis. You treat all blood, body fluids, secretions, excretions (except sweat), non-intact skin, and mucous membranes as if they are infectious. Standard precautions include hand hygiene, wearing gloves and other PPE whenever contact with body fluids is possible, safe linen handling, never recapping needles, and cleaning spills promptly.

Personal protective equipment (PPE) is put on (donned) and taken off (doffed) in a specific CDC order. Questions frequently reverse the order as a trap, so learn both. The guiding rule: gloves go on last and come off first, because they are the most contaminated.

Remove the mask last and by its ties, never by touching the contaminated front, and perform hand hygiene immediately after removing all PPE.

Handling linens, sharps, and spills

• Linens - roll soiled linen with the dirtiest part inward, hold it away from your uniform, never shake it (shaking spreads microbes into the air), and place it in the proper bag at the point of use.
• Sharps - never recap a used needle; drop sharps directly into the puncture-proof sharps container, which is replaced when about two-thirds full.
• Spills - clean blood or body-fluid spills promptly with gloves and the facility-approved disinfectant; report and contain them right away.

Transmission-Based (Isolation) Precautions

When standard precautions are not enough, the nurse adds transmission-based precautions based on how the germ spreads. The aide does not choose the category, but must know what each requires.

A helpful memory aid for airborne diseases is "My Chicken Has TB" - Measles, Chickenpox, TB - the three that require an N95 respirator. Remember the C. diff exception: even though it is a contact precaution, you must use soap and water, not gel, for hand hygiene because the spores survive alcohol.

Worked Example: You are assigned to Mrs. Okafor, who is on contact precautions for MRSA, and Mr. Diaz, who is on airborne precautions for active TB. Before entering Mrs. Okafor's room you don a gown and gloves; after care you doff gloves, then gown, then wash your hands. Before entering Mr. Diaz's room you put on a fitted N95 respirator (a surgical mask is not enough), keep the door closed, and remove the respirator last - outside the room by its straps - then wash your hands. Wearing the wrong mask for TB, or skipping the N95, would put you at real risk and would fail an exam scenario.