Purpose

The purpose of this module is to introduce students to treatment and prevention of infectious viral diseases. Because viruses replicate inside a cell using the host’s machinery to make its proteins and reproduce, treatment for curing viral diseases is difficult. In the case of RNA viruses such as influenza, measles, and polio, the high rate of mutation makes drug design challenging.

The best defenses against viral infection are preventative measures and the body’s immune response. In this module students learn about prevention of infectious disease through public health systems, personal care, and vaccination. Students explore how the body protects itself from viral infections and its immune response to viruses.

Students learn how vaccines activate the immune system to provide protection against viral infections. They then determine why certain viral diseases could be eradicated and the challenges involved.

Learning Outcomes

At the end of the module, student should be able to:

• Identify options for treating viral infections
• Describe approaches to prevention of infectious diseases including public health measures, personal care measures, and vaccines
• Clarify the differences among prevention, treatment, and cure
• Identify the different barriers humans have to viral infections
• Describe the immune response to viral infections, specifically to Ebola and measles viral infections
• Explain how vaccines work with the immune system
• Compare the impact of viruses on reservoir animals and on humans when these viruses emerge as new diseases and explain the causes of the differences
• Identify viruses that could be eradicated, explain how and why, and discuss the barriers to eradication

Assumptions of Prior Knowledge

• Students are familiar with viruses as agents of infectious diseases
• Students know that some contagious diseases are transmitted by direct contact with an infected individual while others are transmitted through sneezing and coughing (airborne)
• Students recognize that personal habits and interactions with their environment influence whether they contract infectious diseases

Materials

For Activity 1 - Preventing the Spread

• Nutrient agar plates (1 for each student)
• 1 package baker’s yeast
• Hard candy
• Household chlorine bleach
• Sterile or distilled water
• 100 mL sterile nutrient broth
• 1 small test tube and tongs/tweezers (for each group)
• 1 large beaker (1000-mL)
• Wax pencils
• Safety glasses
• sterile cotton swab or inoculating loops
• soap and warm water
• sterilized tweezers or tongs