Embedded Files
The Chain of Infection
Germs are spread through a predictable sequence called the "chain of infection." Understanding this chain helps us identify where to intervene and prevent disease transmission.
⬅️👀 Watch the video for more details.
The Six Links
1. Infectious Agent (Pathogen)
These are microorganisms capable of causing disease. Refer to our last lesson.
⬇️
2. Resevoir
The place where pathogens live and multiply. Reservoirs can be humans (patients, healthcare workers), animals, food or environmental sources like contaminated water or surfaces.
⬇️
3. Portal of Exit
How pathogens leave the reservoir. Common portals of exit include respiratory secretions (coughing, sneezing), bodily fluids (blood, urine), and breaks in the skin.
↘️
4. Mode of Transmission
How pathogens travel from one location to another:
Contact transmission: Direct (person-to-person) or indirect (contaminated objects)
Droplet transmission: Large respiratory droplets from coughing or sneezing
Airborne transmission: Small particles that remain suspended in air
Vector-borne transmission: Through insects or animals
Vehicle transmission: Contaminated food, water, medications or medical equipment
⬇️
5. Portal of Entry
How pathogens enter a new host through mucous membranes, breaks in skin, or respiratory tract.
⬇️
6. Susceptible Host
A person whose immune system cannot effectively fight off the pathogen due to factors like age, chronic illness, immunosuppression, or stress.
✏️Label the Chain of Infection in your workbook.
❓For the 3 photos above, what mode of transmission is being depicted in the image.
Record your answers in your workbook.
❓How many times per day do you think the average person touches their face.
Record your guess in your workbook.
⬅️👀Watch this video clip for the answer.
🎯 How close were you??
❓We also learned a new word for indirect contact transmission in the video. What is the new word?
Record the answer in your notebook.
Answers:
Image 1: Droplet transmission
Image 2: Vector transmission
Image 3: Direct Contact transmission
Page updated
Report abuse