1. Chain of Infection Isolation precautions
January 25, 2018

2. Bell Work What is another word for healthcare-associated infection?
What is the number one way to prevent infection?
When should health care workers wash their hands?
Only when they are visibly dirty
Every 20 minutes
Before providing care and between patients
Only at the beginning of the work day

3. Standard
Correlate the function of normal flora with homeostasis and relate deviation to disease states. Evaluate specific measures to prevent deviation that are aligned with accepted standards of care.
Assess the differences between healthcare associated infections and non-healthcare associated infections using examples drawn from mock case studies. Support explanations with relevant surveillance statistics, preventive measures, and methodologies concerning outbreak detection, management, and education.

4. Objective By the end of class, students will be able to:
Apply and Identify the steps in the Chain of Infection

5. Classification of Infections and Diseases
Endogenous – begins inside the body
Exogenous – caused by something outside the body
Opportunistic – occur when the body’s defenses are weak

6. Infectious and Communicable Diseases
An infectious disease results from an invasion of microorganisms.
A communicable disease is a type of infectious disease that can be transmitted from one person to another person (direct or indirect contact)
Not all infectious diseases are communicable - cardiovascular diseases, cancers, chronic respiratory diseases and diabetes 
Infectious and Communicable Diseases
Diseases are also classified according to whether or not they can be transmitted from one person to another person. An infectious disease results from an invasion of microorganisms. A communicable disease is a type of infectious disease that can be transmitted from one person to another person.
Not all infectious diseases are communicable. For example, lyme disease is caused by bacteria, but it cannot be transmitted from person to person. Hepatitis B, on the other hand, is caused by a virus. The hepatitis B virus can be passed from person to person if exposure to blood or bodily fluids occurs.
One of the goals of infection control is to prevent the transmission of these communicable diseases.

7. Draw a Chain in Course Notes

8. Chain of Infection: Causative agent Reservoir Portal of exit
Mode of transmission
Portal of entry
Susceptible host
Chain of Infection
For a communicable disease to be passed from one person to another, certain conditions must be met. These conditions are known as the chain of infection. The following list describes the steps in the chain of infection:
The chain of infection begins with a pathogen, which is called the causative agent.
The causative agent must find a reservoir, or a place for the causative agent to live and grow. A reservoir could be a human, an animal, or any surface or object.
Next, the pathogen must have a portal of exit to leave the reservoir. In humans, pathogens can leave the body through blood, bodily fluids, or excrement.
After the pathogen leaves the reservoir, it must be moved to another reservoir where it can continue to live and grow. This process is called the mode of transmission.
The pathogen must have access to a portal of entry, which is the place the pathogen will enter the new reservoir.
If the new reservoir has weak defenses, it will contract the disease or infection. The new reservoir is called the susceptible host.
If any part of the chain is broken, the spread of the disease or infection will stop. Health care workers must practice principles of infection control in order to break the chain of infection.

9. Causative Agent = Pathogen
Disease-producing microorganism; bacteria, virus, fungus, protozoa, and rickettsia
Present in blood or body fluids, called “bloodborne pathogens”
Pathogens need an environment that enables them to survive, grow, and multiply
The human body is a perfect environment
The first link in the Chain of Infection is the pathogen. The pathogen is required for any infection to be present. The five types of pathogens are bacteria, virus, fungus, protozoa, and rickettsia. Pathogens can be present in our body fluids, including in blood. Pathogens are often referred to as bloodborne pathogens.

10. Reservoir Human, animal, or insect that is infected with disease
Other reservoirs may be water, food, and contaminated objects
Host may be symptomatic or asymptomatic
Reservoir host is contagious even though he or she may not appear ill
A reservoir host is a person who has the pathogen present in his or her body. The reservoir host may be sick and have symptoms of illness or may be perfectly healthy in appearance. A person who is ill but does not show symptoms is called asymptomatic.

11. Portal of Exit Pathogen must be able to exit reservoir host
Any body opening lined with mucous membranes: eyes, nose, throat, vagina, rectum, penis
Injury or surgery
Blood, body fluids: vaginal secretions, semen, urine, feces
In order for the Chain of Infection to continue to spread, the pathogen must be able to leave the reservoir host to infect another person.

12. Mode of Transmission
Direct contact— person-to-person contact or skin- to-skin contact
Handshaking, kissing, and sexual contact
Indirect contact— fomites; ticks, fleas, lice, and countertops
Indirect contact includes airborne and droplet infection—sneezing, coughing, and talking
Transmission includes direct contact, indirect contact, and airborne transmission.

13. Portal of Entry Pathogen must find entry into new host
Any opening in the body lined with mucous membranes: nose, mouth, throat, vagina, penis, rectum
Wounds to the skin
Just as the pathogen has to leave the reservoir host in order to continue to spread, the pathogen also has to find a way to enter another person. The means of exit are exactly like the means of entry—mucous-lined membranes and wounds or nonintact skin.

14. Susceptible Host Weakened immune system Poor hygiene
Inadequate nutrition
Stress
Chronic disease
Poor environmental conditions
Elderly
Very young
Certain medications
Smoking
Alcohol abuse
A variety of conditions contribute to a person being a susceptible host. Medical assistants work to make sure that we do not become a susceptible host. By eating well, exercising, practicing good hygiene, and so forth, medical assistants can lessen the amount of times they are ill.

15. Chain of Infection Video
Write down all the ways you see the chain of infection spread.

16. Chain of Infection
Infection-Fact-Sheet.pdf

17. Chain of infection
For each example, choose the link in the infection chain that it represents:
Causative Agent, Reservoir, Portal of Exit, Mode of Transmission, Portal of Entry
Or Susceptible Host
Influenza Virus An Elderly Person
A dirty scalpel A Handshake with a person who just coughed
A nurse with dry cracked hands 10. Touching a faucet after washing your hands
Sneezing A mosquito that has the West Nile Virus
Improper hand washing Breathing in droplets of a person with the flu
A patient with pneumonia 13. Kissing a person
A surgical incision Ingesting Contaminated Food

18. Get with your shoulder partner and quiz each other on your vocabulary
Work it out!
Work on Sub Grid #3
Get with your shoulder partner and quiz each other on your vocabulary

19. Bell Work
In the chain of infection, a causative agent could be?
What is an example of a portal of entry or exit?
What is an example of a mode of transmission?
What is a susceptible host?

20. Journal Work Go to Web site and read: Breaking the Chain of Infection
Write 3 paragraphs summarizing what you read. Make sure you have an introduction (1-2 sentences, a body (3-5 sentences) and a closing (1-2) sentences.