Epidemics: Ebola
The five lessons of the Epidemics: Ebola unit can be used as a stand alone or as a supplement to the Great Diseases Infectious Disease (ID) curriculum. The purpose of these lessons is to provide high school students with a basic understanding of how viruses cause disease, how infectious diseases spread to become epidemics and the challenges of bringing an epidemic under control, all from the perspective of the Ebola virus and the most recent Ebola epidemic that occurred in West Africa in 2014. Besides learning specific information about the Ebola epidemic, students will be able to extrapolate the general principles of infectiousness and disease spread to other emerging epidemics, and will appreciate the importance of vaccines in preventing disease spread.
Lesson 1
How do infectious diseases spread?
The goal of the first two lessons is to introduce students to the factors that influence how an infectious disease spreads through the population. This lesson has two main purposes: First, it allows students to actively experience a disease transmission simulation. Second, it relates the findings from the simulation to the notion that immunity and vaccination can impact the spread of infectious diseases. By addressing the question ‘if we vaccinate half the class and run the simulation again, how many people would get infected?’ students learn that vaccines not only protect individuals against disease but more importantly prevent the spread of disease in the population.
Lesson 2
How can we measure contagiousness?
This lesson builds on what we learned about disease spread in Lesson 1. We define the international metric for communicating about how contagious an infectious disease is, the case reproduction number (RO). Students learn about the 4 main factors that impact RO: how the infection is transmitted; how much contact the infectious person has with others; how long they are infectious and how susceptible the population is to infection. After observing how diseases with a range of case reproduction numbers spread in a population, students then calculate the percent of the population that would need to be immune to stop the spread of common infectious diseases. This reveals a number of surprising findings, including the percent of the population that would need to be vaccinated to stop the spread of measles compared to the flu.
Lesson 3
How does infection with Ebola virus happen?
The previous two lessons focused on how infections spread, the factors that influence the case reproduction number, and the significance of herd immunity in protecting a population. In this lesson we turn our attention to the Ebola virus itself. First students put viruses into the overall context of pathogens in relation to their size, then they learn about how the Ebola virus is constructed and the features of its structure that contribute to its ability to infect and spread disease.
Lesson 4
How do Ebola infections spread?
Today students will work to organize their knowledge of how the Ebola virus infects its hosts and how infection leads to the spread of Ebola disease by completing the Ebola Epidemic Arrow. Then, armed with this knowledge in Lesson 5 the students will work in groups, taking on the perspective of an important stakeholder in the fight against Ebola.
Lesson 5
How can we work together to stop an Ebola epidemic spreading?
In this lesson students apply what they have learned about infectious diseases in general and Ebola in particular as they take on the perspective of an important stakeholder in the fight against Ebola. The stakeholder roles were selected to flesh out critical challenges that were faced when combating the recent Ebola epidemic in West Africa. Specifically, the roles emphasize conflicts that arise in the absence of effective health care, treatments or preventative measures.
