| A | B |
|---|
| A microbial organism with the ability to cause disease | Infectious agent |
| Ex. of Infectious agents | Examples: bacteria, virus, fungi, and parasites |
| A place within which microorganisms can thrive and reproduce | Reservoir |
| Ex. of Reservoirs | Examples: human beings, animals, and inanimate objects such as water, table tops, and doorknobs |
| A way for a microorganism to leave the reservoir | Portal of exit |
| Ex. of Portal of exit | Examples:microorganism may leave the reservoir through the nose or mouth when someone sneezes OR leave the reservoir of an infected bowel |
| Method of transfer by which the organism moves or is carried from one place to another | Mode of transmission |
| Ex. of Mode of transmission | Example:the hands of the health care worker may carry bacteria from one person to another |
| An opening allowing the microorganism to enter the host | Portal of entry |
| Ex. of Portal of entry | Example: body orifices, mucus membranes, or breaks in the skin OR tubes placed in body cavities, such as urinary catheters |
| A person who cannot resist a microorganism invading the body, multiplying, and resulting in infection | Susceptible host |
| Ex. of Susceptible host | Example: a person lacks the immunity or physical resistance to overcome the invasion by the pathogenic microorganism |
| Links 1 and 2 in Chain of Infection | infectious agent AND reservoir |
| Links 3 and 4 in Chain of Infection | Portal of exit AND Mode of transmission |
| Links 5 and 6 in Chain of Infection | Portal of entry AND Susceptible host |
