Have students read Agents of Disease. The purpose of this reading is to introduce students to infectious agents including parasites, bacteria, and viruses. It is important for students to understand the differences among the different organisms, how they are transmitted and how they cause disease. Major epidemics and pandemics, which students will be exploring in the next activity, have been caused by viruses and bacteria. The modules in this series will focus primarily on viruses, specifically Ebola, measles, and COVID-19, but will also mention bacteria at times with resources that discuss the ecological, social, economic, cultural and biological factors that can lead to epidemics and pandemics - as well as the impact of these diseases on the infrastructure of societies.

Videos

Introduction to Bacteria

Key parts of the video are listed below.

Topic	Time Frame
Comparing Cell Structure to Human Cells	6:25 - 7:28
Fleming Experiment	14:02 - 16:07

Introduction to Viruses

Key parts of this video are listed below.

Topic	Time Frame
Composition of virus	1:03-2:46
How viruses enter cells	3:18-5:48
How viruses take over cellular processes to produce more viruses.	5:49-7:56
How replicated viruses exit host cells.	7:57-9:58

Activity: Timeline of outbreaks, epidemics, and pandemics

This interactive timeline, which is both below and in the student activity, shows the occurrence of a sample of outbreaks, epidemics, and pandemics over human history. Students should recognize that epidemics are part of human life, are the result of human activity, and have consequences for the infrastructure of societies. For each disease information is provided about the biology of the agent of disease, the ecological, social, cultural, and biological factors involved in spread of the disease, and the consequences of the disease.

Possible ways to use the timeline include the following:

• discussing each example as a whole class and looking for common patterns in the factors;
• having a “jigsaw” learning strategy in which teams become experts in each epidemic or disease and then sharing their understandings to the class;
• having students as individuals or in pairs determine the ecological, social, cultural, and biological factors involved in spread of the disease.

Students will be returning to the timeline in other modules in this series.