Infectious Diseases: Unit 1

Why should we care about infectious diseases?

The goal of this unit is to improve students’ understanding on the impact that infectious diseases had and still have on societies, and to introduce the factors responsible for infectious diseases. The unit begins by engaging the students by presenting the impact of infectious diseases from historical and current perspective. It continues with introduction to microbes as the infectious agents and focus on their structure and functions, especially in relation to microbes’ infectivity and pathogenicity. The unit is completed by introducing the roles of different protective barriers that the human body has to fight off invaders.

Lesson 1

The flu, do we overreact?

This lesson is intended as an ‘engage’ as well as to address the larger question: Why should we care about infectious disease? You will capture student interest by stimulating a discussion focused on what makes a disease infectious. The flu is then used to illustrate the potential impact infectious diseases can have. Students are asked to question the importance of flu shots. The students revisit this question again after watching a video about the Spanish flu pandemic of 1918.

Objectives – Explain what a disease is.
– Explain what makes a disease infectious.
– Explain why we care about infectious disease.
– Name three impacts the flu has on society.
Activities – Pros/cons of a flu shot
– Watch flu pandemic video
Materials Printed:
– Lesson worksheet

– Video (see PowerPoint)
Homework Have the students write a paragraph about three globally important infectious diseases of their choice.

Lesson 2

How infectious disease has molded history—including ours

This lesson is intended to emphasize that infectious diseases shape history and our day-to-day lives. You will guide the students using the Poodwaddle Clock to assess current rates of infection and mortality caused by select globally significant diseases. Then, you will explore how infectious diseases have impacted history.

As a homework review before the jigsaw in Lesson 1.3 students may need to be reminded of the general structure of a bacterial cell. I thought this might be a good website reminder. It will help with the fluidity of the lesson.
—Teacher who piloted this lesson at Boston Latin School

Objectives – List a number of globally significant infectious diseases and explain mortality.
– Explain the societal effects of infectious diseases.
– Indicate consequences of HIV epidemic.
Activities – Poodwaddle Clock Activity.
– Discussion of epidemics.
Materials Printed Materials:
– Lesson worksheet

– Internet access
Homework Have the students list 4-5 behaviors we use to avoid transmission of infectious diseases, and explain what they might prevent.

Lesson 3

What is an infectious agent? (1) What bacteria need to make us sick

This lesson has two purposes. First, it is intended to demonstrate how infectious disease influences our day-to-day habits as we try minimize our exposure to pathogens. Second, the students will be introduced to bacterial structures and their functions in disease.

Objectives – Explain common practices used to avoid infectious diseases.
– Describe the bacterial structures that are critical for infection.
Activities Jigsaw activity.
Materials Printed Materials:
– Lesson worksheet
– Jigsaw reading
Homework Complete lesson worksheet.

Lesson 4

What is an infectious agent? (2) What viruses do to make us sick

This lesson has two purposes: First, it introduces viruses by exploring relative sizes of bacteria and viruses and how this contributes to their modes of action. The lesson then extends the previous focus on bacterial structures by showing how viral structures also play important roles in infectivity and disease.

Objectives – Describe the relative sizes of bacteria and viruses compared to a eukaryotic (host) cell.
– Name viral structures and describe their functions in viral infection.
– Describe the viral life cycle.
Activities Size comparison calculations.
Materials Printed Materials:
– Lesson worksheet

– Video (see PPT)
Homework Venn Diagram worksheet.

Lesson 5

So why aren’t we always sick? Our body’s defenses

We are covered in bacteria and exposed to viruses all the time, but we rarely get sick. Why? Students will develop their understanding of sterility and the notion that the interior of the body is sterile while the exterior is non-sterile. This will involve a new concept: the outside of the body includes all areas that contact the environment, including the intestinal lumen. Based on these ideas, students will then identify host barriers designed to protect against infection.

Objectives – Define ‘sterility’ and explain which parts of our bodies are non-sterile (external) and sterile (internal).
– Explain how commensal bacte-ria protect against infection.
– Describe the external barri-ers the body uses to prevent infection.
– Describe the internal defenses the body uses to prevent infection.
Activities – Make a list of the sterile and non-sterile body parts.
– Brainstorm protective barriers.
Materials Printed Materials:
– Lesson worksheet – Quizzes

– Videos (see PPT)
Homework Study for the Unit 1 quiz.

Teacher Prep: Unit 1 Lesson Overview Videos

In the YouTube embed below, click the order listing in the upper right to toggle the display for the full playlist.