3.3 Infection Control Principles

Breaking the Chain

Infection-control questions are among the most predictable on the NCLEX-PN because the principles are concrete and rule-based. The exam wants the LPN/LVN to identify the weakest, most controllable link and to apply Standard Precautions as the default for every patient.

The Six-Link Chain of Infection

The mode of transmission is the link nurses control most directly — and hand hygiene is the most powerful tool against it. The exam may ask you to identify which intervention breaks which link: sterilizing instruments targets the infectious agent, proper disposal of soiled linen addresses the reservoir and portal of exit, covering a draining wound closes a portal of exit, aseptic dressing technique protects the portal of entry, and immunization or improving nutrition strengthens the host.

A susceptible host is anyone with reduced defenses — the very young, the very old, the immunocompromised, those with chronic disease, invasive devices, or poor nutrition.

Modes of Transmission

Standard Precautions

Standard Precautions apply to all patients, all the time, regardless of diagnosis or presumed infection status, and treat all blood and body fluids, secretions, excretions, non-intact skin, and mucous membranes — except sweat — as potentially infectious. They include hand hygiene, gloves when contacting body fluids, a gown for splash or soiling risk, mask and eye protection during procedures that may spray, safe injection practices (one needle, one syringe, one patient, single-dose vials preferred), respiratory hygiene/cough etiquette, safe handling of contaminated equipment and linens, and no recapping of needles.

They were created on the principle that any patient may carry a bloodborne pathogen without the staff knowing, which is why they are non-negotiable and applied universally.

Hand Hygiene

Follow the WHO "5 Moments": before touching a patient, before a clean/aseptic task, after body-fluid exposure risk, after touching a patient, and after touching the patient's surroundings.

High-yield trap: alcohol rub does not kill Clostridioides difficile spores or norovirus — only soap-and-water friction physically removes them. The exam loves this distinction. Proper soap-and-water technique: wet hands, apply soap, lather and scrub all surfaces including between fingers and under nails for at least 20 seconds, keeping hands lower than the elbows so water and contaminants run off the fingertips, then rinse and dry with a clean towel and use that towel to turn off the faucet.

Remove rings and keep nails short and natural — artificial nails harbor pathogens and are banned in many facilities for direct-care staff. Gloves never replace hand hygiene; perform hand hygiene before donning and after removing them.

Personal Protective Equipment (PPE)

Donning (clean to dirty): 1) Gown, 2) Mask/respirator, 3) Goggles/face shield, 4) Gloves (last, over the gown cuff).

Doffing (dirty to clean): 1) Gloves (most contaminated), 2) Goggles/face shield, 3) Gown, 4) Mask/respirator (last, after leaving the room for airborne). Perform hand hygiene after doffing, and again whenever hands may be contaminated.

Worked Example

The LPN finishes a dressing change on a patient with a draining wound, removes gloves, and is about to leave for another room. The first action is hand hygiene before doffing the remaining PPE and before touching anything else — gloves frequently have micro-tears, so clean hands cannot be assumed.

Disinfection, Sterilization, and Surgical Site Prevention

The NCLEX-PN expects the LPN to distinguish three levels of decontamination. Cleaning physically removes visible soil with soap, water, and friction and must precede disinfection. Disinfection uses chemicals to kill most pathogens on surfaces; high-level disinfection kills nearly all organisms except large numbers of spores and is used for semi-critical items such as endoscopes.

Sterilization destroys all microbial life, including spores, typically via steam autoclave (moist heat under pressure), ethylene oxide gas, or chemical sterilants, and is mandatory for critical items that enter sterile tissue or the bloodstream.

Finally, the LPN supports host defenses by promoting adequate nutrition and protein intake, encouraging fluids, supporting timely immunizations (influenza, pneumococcal, COVID-19, Tdap), and minimizing the duration of invasive devices such as urinary catheters and IV lines, each of which is a portal of entry.

Common NCLEX-PN Traps

• Using alcohol rub after C. diff care.
• Reversing the doffing order (gloves come off first, not last).
• Treating Standard Precautions as optional based on diagnosis.
• Reusing or washing single-use gloves.