Lesson Plan: KS3 Science – How Diseases Spread

  • Lesson Plan: KS3 Science – How Diseases Spread


Ebola is an alarming illness that forms a significant percentage of the daily international news. Helping students to understand the disease and the nature of how a disease spreads is part of a strategy that can be used in the classroom to promote engagement with disease prevention of all types. A key aim is to promote spiritual, cultural, moral and social links by encouraging students to empathise with the victims of Ebola and investigate the circumstances that many West Africans are living in even without this added threat. Students can feel empowered, investigating their own strategies and ideas that could be used to fight the epidemic.

Your mission is to become an expert on the deadly Ebola virus, a pathogen that has already claimed the lives of thousands of people in West Africa and which leading international health organizations predict could reach tens of thousands before the virus has run its course.

With no cure or vaccine, local and international health workers are facing horrendous conditions as they strive to save lives and spread awareness of the disease.

Can you lead a team of students to design a strategy to contain Ebola?


Child Zero

The current Ebola virus outbreak started with one person: a 2-year-old-child who died on December 6, 2013. This child has been named “Child Zero” representing that they are the first person in the outbreak known to have become infected with the pathogen. By 1 January 2014 the child’s mother, 3-year-old sister, grandmother and a traditional African healer had all died of the disease. It is unclear how Child Zero caught the virus although bushmeat is thought to be the origin, in particular fruit bats. In this starter activity students are asked to imagine that they are a teenager living in the same town as Child Zero. They need to use the internet to research and write a sequence of diary entries describing everyday life in their town, Guéckédou in Guinea. They should imagine how news of the virus begins to spread and how people around them react. They could explore the idea of what families might do if they suspect that one of them has contracted the virus. They could be afraid of the doctors who might come to take their family member away – do they hide them and try and care for them alone? Some children have lost all of their families to the disease – how will they cope and survive? The aim of the activity is to raise awareness of the type of lifestyle that people in Western Africa are living and how this can challenge western ideas of how the virus should be tackled or contained. Students could also present this section as a sequence of newspaper articles in the Guéckédou Gazette, or even film a news report for the region.


* Virology in action

A virus is a small infectious pathogen that can only replicate inside the living cells of other organisms. They use the host cell to produce multiple copies of themselves; more than 1000 copies can come out of one infected cell, resulting in an exponential increase in the number of viruses in the host and each infected host cell is killed in the process. If enough cells die the whole organism will start to suffer the effects. Investigate the spread of a virus using this interesting activity from the Discovery Channel [Additional Resource 1]. Students write their names on a small square of paper and place it in a box. The teacher selects one name from the box; this person, who will remain a mystery for now, has a virus. Students then move around the classroom each carrying a worksheet. For the first round, students tap two of their classmates at random and record their names in the chart on the worksheet. In round two they tap two different classmates and in round three they tap two further classmates. When everyone has completed three rounds the teacher reveals the name of the infected person. Students look at their worksheet to see if they had direct contact with this person. If so their names are also recorded on the board. Now students check their worksheet chart again to see if they had contact with any of the people listed on the board. If so, they had indirect contact with the infected person. Students will be surprised to discover that through only three rounds of contact, most of the class have been ‘infected’. Extension activities and questions provided on the worksheet will be useful to stretch and challenge more able students.

* The Epidemiologic Triangle

Introduce this section of the lesson by playing students an alarming clip from the trailer for Outbreak, a 2011 movie which charts the development of a deadly virus in the USA [AR2]. Ask students to respond to the clip – is it realistic? What elements of science are mentioned in the clip and do you think an outbreak of Ebola in the UK should be handled in this way?

In practice scientists use a model called the Epidemiologic Triangle to study health problems and to understand how a disease spreads.

In the diagram the Agent is the microbe that causes the disease, the Host is the organism harbouring the disease and the Environment is the external factors that cause or allow disease transmission. A superb resource from PBS Newshour [AR3] contains a lesson plan and student guide to help students understand Ebola and to design a strategy to contain the rapidly growing outbreak in West Africa. Students use the thoughtfully prepared resources on the website to explore the agent, the host and the environment. After researching as much material as possible in teams they complete an assessment which is designed as a strategic plan. It includes an Epidemiological Triangle, a graphic organiser for key facts and prompts to help students create their own evidence based recommended strategy to contain the Ebola outbreak [AR4]. Other resources on the website that could be used to extend gifted and talented students include a data analysis worksheet which develops students’ mathematical and geographical skills using data from previous outbreaks [AR5].

About our expert

Dr Joanna L. Rhodes M.Chem, D.Phil, MRSC is a teacher of science at Shelley College, Huddersfield.


A great fear people have in relation to a deadly virus such as Ebola is that it could mutate to become airborne. In this homework activity, students use articles from National Geographic [AR7] and the Washington Post [AR8] to produce a report for the Prime Ministers COBR Committee [AR9] on the UK’s preparedness for the virus to arrive, how viruses mutate and the likelihood of Ebola becoming airborne.


Ebola spreads through direct contact with infected bodily fluids or tissue. The virus can be transmitted when an infected person’s vomit, blood or other fluids contact another person’s mouth, eyes or openings in their skin. Even after a person has died, the virus persists. In West Africa where funeral rites include washing, touching and kissing corpses by family members, putting the dead to rest can be just as deadly as caring for a living patient. At the time of death a patient can have 1 billion copies of the Ebola virus in 1cm3 of blood! In this activity students are asked to design a poster and flyer as part of their strategic plan to be displayed and distributed in towns like Guéckédou where the outbreak began. The poster and flyer should be informative and easy to understand. Students should include advice on caring for sick relatives and looking out for the symptoms of Ebola. They could explain where to take a sick individual to be diagnosed and might also include advice on how to deal with the body of a relative who has died. Some students may want take on the challenge of creating a version using only pictures or illustrations in case the person receiving it cannot read. Examples you could share with students can be found at the Center for Disease Control and Prevention website [AR6].