Download Chain of Infection

Chain of Infection
Learning Outcomes
Identify the elements within the chain of
infection including reservoirs and routes of
transmission.
The Chain of Infection
Several things have to take place for infection
to occur. This is referred to as a 'Chain of
Infection'.
The links in a chain are interconnected and
hold the chain together.
Your goal as a Student Nurse is to identify
when and how to break those links and thereby
break the Chain of Infection.
Chain of Infection
1
2
3
4
5
6
The Infectious Agent
The infectious agent is a
micro-organism with the
ability to cause disease.
Infectious agents may be
bacteria, viruses, fungi,
parasites or prions.
The Reservoir
If the conditions are right, Reservoirs of
Infection will develop.
Micro-organisms need the right conditions
if they are to live and grow, such as:
•Warmth
•Moisture
•A food source.
In the right conditions micro-organisms
can multiply rapidly.
The Means of Exit
Micro-organisms leave the reservoir by various
means.
In humans, Means of Exit are usually:
 Excretions, e.g. diarrhoea, stool or vomiting
Secretions, e.g. as body fluids like blood and
saliva
Droplets, e.g. from coughing and sneezing
Skin, e.g. skin scales.
The Mode of Transmission
To move from the reservoir, a micro-organism needs a
Mode of Transmission to a susceptible host or home.
These transmission routes include:
Direct contact (e.g. hands)
Indirect contact (e.g. via equipment)
Inhalation (e.g. airborne / droplet)
Inoculation (e.g. deliberate or accidental puncture of
the skin)
Ingestion (e.g. food)
Intercourse
Mother to Infant transmission.
In a healthcare environment direct and indirect contact
are the most important transmission routes.
Direct hand contact from health professionals moving
from one patient to another is the most common.
Portal of Entry
The portal of entry is the path by which
the infection is able to enter the
susceptible host.
Entry of the infection can be made via
the respiratory tract, GI tract, GU tract,
compromised skin and mucus
membranes.
The Susceptible Host
Patients accessing healthcare are generally unwell:
They may have diseases or be receiving
treatments that weaken their immune system, such
as cancer or diabetes.
They may have had surgery.
They may also be malnourished.
Patients are commonly put in an environment
where they share facilities with other patients
within a fairly confined space.
And they may also be dependent on health
professionals to help with activities of daily living.
Summary and Conclusion
This session provided an introduction to the 6 links
in the chain of infection.
It is very important to that as student nurses you
understand of the six links in the chain of infection
and how they influence and impact on each other.
Your goal as a Student Nurse is to identify when
and how to break those links and thereby break the
Chain of Infection.