The chain of infection consists of six links: (1) an infectious agent, (2) a reservoir where the agent lives, (3) a portal of exit from the reservoir, (4) a mode of transmission to a new host, (5) a portal of entry into the new host, and (6) a susceptible host. The chain can be broken by identifying the infectious agent, practicing proper hygiene, controlling portals of exit through standard precautions, preventing transmission routes, protecting portals of entry, and recognizing susceptible hosts. It is everyone's responsibility to interrupt the chain of infection through these measures.

1. The Chain of Infection

2. As healthcare
professionals, it is
important to
understand two
things about
infection:

3. 1.the various ways infection can
be transmitted
2. the ways the infection chain
can be broken

4. There are six
links
in the chain of
infection :

5. 1st - The Infectious Agent
-any disease-causing
microorganism
(pathogen)

6. 2nd - The Reservoir
-the place where the
pathogen originally lives

7. Hosts that do not show any outward signs or
symptoms of a disease but are still capable
of transmitting the disease are known as
carriers.
What are “Carrier Hosts”

8. 3rd - The Portal of Exit
-route of escape of the pathogen
from the reservoir.
Examples: respiratory
secretions, blood
exposure, breaks in
skin.

9. 4th - The Mode of Transmission
-method by which the pathogen
gets from the reservoir to the
new host

10. Transmission may occur through:
direct contact
occurs through skin-to-skin contact,
kissing, and sexual intercourse

11. air

12. insects

13. 5th - The Portal of Entry
-gaining access to a new host or
reservoir

14. Respiratory System

15. Gastrointestinal System

16. Urinary & Reproductive Tracts

17. Breaks in Protective Skin Barrier

18. 6th - The Susceptible Host
-the organism that accepts the
pathogen
A person who is sick, stressed, etc.

19. Organisms with strong immune
systems are better able to fend off
pathogens.

20. Organisms with weakened immune
systems are more vulnerable to the
support & reproduction of pathogens.

21. -The essential part of patient care &
self-protection.
How to interrupt the chain of
infection:

22. 1. Pathogen Identification
-identification of infectious
agent & appropriate treatment

23. 2. Hygiene
-potential hosts &
carriers must practice
maintain proper
personal hygiene

24. 3. Control Portals of Exit
-we must practice standard
precautions:

25. (Control body secretions & wash
hands according to protocol.)

26. 4. Prevent a Route of
Transmission
-prevent direct or indirect contact
by:
1.Proper handwashing
2.Disinfection & sterilization techniques
3.Isolation of infected patients
4.Not working when contagious

27. Antiseptics
• Antiseptics are solutions that are applied
directly to the skin. They prevent or slow
the growth of pathogens.
• Examples: Alcohol, Betadine, Listerine

28. Disinfection
• Disinfection uses strong chemicals to kill
many pathogens on objects
• Examples: Bleach, Lysol, etc.

29. Sterilization
• It is the best way to kill all microbes and
their spores
• Examples: Autoclave (steam under
pressure)

30. 5. Protect Portal of Entry
-We must make sure that ports of
entry are not subjected to
pathogens.
(nose, mouth, eyes, urinary tract,
open wounds, etc.)

31. 6. Recognition of Susceptible
Host
-We must recognize & protect high-
risk patients

32. Remember--breaking the chain of
infection is the responsibility
of everyone.