4.1 Chain of Infection
Key Takeaways
- Breaking any link in the chain of infection can stop disease spread.
- The chain includes infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.
- CNAs break the chain through hand hygiene, PPE, cleaning, linen handling, and reporting symptoms.
- Older adults and chronically ill residents are often susceptible hosts.
- Infection control questions often ask what action prevents spread first.
The Infection Chain
Infection spreads through a chain. If you break one link, the organism cannot continue spreading.
| Link | Example | CNA Prevention |
|---|---|---|
| Infectious agent | Bacteria, virus, fungus | Cleaning and disinfection |
| Reservoir | Resident, equipment, linen | Keep clean and dirty separate |
| Portal of exit | Blood, stool, urine, droplets | Gloves, masks, proper disposal |
| Transmission | Hands, surfaces, droplets | Hand hygiene and PPE |
| Portal of entry | Mouth, wound, catheter | Protect skin and devices |
| Susceptible host | Frail or immunocompromised resident | Vaccination support, hygiene, nutrition |
Why CNA Actions Matter
CNAs touch residents, linens, equipment, call lights, meal trays, and bathroom surfaces. That makes infection control part of every task, not a separate chapter.
The most common transmission route is contaminated hands. Gloves help, but gloves can also spread organisms if used incorrectly.
Clean vs Dirty
Clean items should stay clean. Dirty items should move toward disposal, laundry, or cleaning without touching clean supplies.
Do not place clean linen on the floor. Do not put used supplies on the bedside table. Do not carry contaminated linen against your uniform.
Resident Risk
Many long-term care residents have higher infection risk because of age, chronic illness, wounds, catheters, poor nutrition, or limited mobility.
Report signs that may indicate infection:
- Fever or chills.
- New confusion.
- Burning with urination.
- New cough or shortness of breath.
- Redness, drainage, or odor from a wound.
- Diarrhea or vomiting.
Exam Rule
When in doubt, choose the answer that breaks transmission while protecting dignity. Hand hygiene, gloves when needed, clean handling, and prompt reporting are high-yield.
Which action best breaks the mode of transmission in the chain of infection?
Clean linens fall on the floor. What should the CNA do?