N213: Health Differences Across the Life Span 3

N213: Health Differences Across the Lifespan 3 Study Guide

Chapter One: Infectious and Communicable Diseases Infectious and communicable diseases are illnesses that can be spread from one person to another. These are also commonly referred to as contagious diseases. The causative organisms are bacteria, viruses, parasites, fungi, and protozoa. The person who catches one of these causative organisms becomes known as the host . In order for someone to get acutely ill with an infectious or communicable disease, all the conditions have to be in place. Let’s take a look at how that happens: 1.1 Infections Chain of Infection The person who gets sick or catches a communicable disease goes through a cycle known as the “chain of infection.” This is when the causative organisms, that cause infectious and communicable disease, leave one host by “mode of transmission” and enter another host. There is a “portal of exit” out of one host and a “portal of entry” into the new host.

Infectious Organism

Susceptible Host

Reservoir

Portal of Exit

Portal of Entry

Mode of Transmission

©2017 Achieve Test Prep Page 7 of 204 The chain of infection first starts with an organism, and then a reservoir. It then finds a way out of the reservoir and travels on a mode of transmission. This is when the organism goes through a portal of entry into a susceptible host. With infectious and communicable diseases, this cycle can repeat itself over and over spreading illness.

Made with FlippingBook - Online catalogs