Quick Reference
The chain of infection describes the six links necessary for an infection to spread. Breaking any link interrupts transmission.
| Link | Description | How to Break It |
|---|---|---|
| Infectious Agent | Pathogen capable of causing disease | Cleaning, disinfection, appropriate treatment |
| Reservoir | Where pathogens live or multiply | Environmental cleaning, food safety |
| Portal of Exit | How pathogens leave the reservoir | Cover wounds, contain drainage, respiratory hygiene |
| Mode of Transmission | How pathogens spread | Hand hygiene, PPE, safe equipment handling |
| Portal of Entry | How pathogens enter another host | Protect skin, aseptic technique |
| Susceptible Host | Person vulnerable to infection | Vaccination, nutrition, appropriate preventive measures |
Types of Infectious Agents:
- Bacteria
- Viruses
- Fungi
- Parasites
Important Considerations
- Hand hygiene interrupts transmission.
- Intact skin and mucous membranes provide important protection.
- Infection can spread through direct contact, indirect contact, droplets, or airborne routes.
- A person can carry certain pathogens without showing symptoms.
- Prevention requires multiple measures, not just PPE.
Related
Sources
- CNA Module 6 — Infection Prevention & Control
Flashcards
Why break a link in the chain of infection?02-mechanisms / reference-guidelines
Answer
To interrupt transmission to a susceptible host.