Schoolzone: Teaching zoonoses in schools

Zoonoses are a fascinating topic for school students; the spread of diseases that can pass between animals and humans holds a gruesome appeal. But how can we teach about zoonoses in schools in an engaging way, when, for obvious reasons, we cannot carry out wet laboratory experiments using any of these pathogens? In this article we explore student activities covering various aspects of the subject, including emerging zoonotic diseases, biosecurity and the spread of infection.

Investigating emerging zoonotic diseases

An emerging zoonotic disease is one that is newly recognised or evolved, or that has already been seen in humans previously but has shown an increase in incidence or geographical area. Examples include Ebola, West Nile virus and avian influenza. They can be caused by any type of infectious agent (bacteria, virus, fungi, prion or protozoa) and can be spread by pets, farm animals or wild animals.

STUDENT RESEARCH PROJECT

This topic provides a good opportunity to use a multi-disciplinary approach, with students able to research several aspects of an emerging zoonotic disease. Important microbiological themes to consider include:

• What micro-organism causes the disease?
• What is known about the biology of this micro-organism?
• Does this microbe have a history of causing disease in other geographical locations, or in different species?
• How does this microbe transmit the disease? This could be through direct or indirect transmission.

As well as the microbiology behind each disease, the students can also investigate the epidemiology of the disease, anthropological, social and economic impacts of the disease, and what can be done from a public health perspective to minimise the spread of the disease. It can cover other topics in biology and chemistry, as well as history, geography and health studies. The results of this desk-based research could be presented as a poster, a presentation, or a policy briefing.

Biosecurity: preventing the spread of zoonotic diseases

It is a vital skill for developing scientific researchers to be able to write good quality risk assessments and consider appropriate codes of practice. However, this can sometimes be a tedious task and not particularly engaging for students. Using a subject, such as zoonotic diseases, that has serious consequences if correct procedures are not followed, adds a good level of interest to the work and helps students think outside of their usual laboratory situations.

STUDENT WORKSHOP

Pairs of students are given a specific environment to investigate. This could be different types of farming environments, a veterinary surgery, a home with domestic or exotic pets, or a remote field station. Students then write a full risk assessment and a code of good working practice for the people working in or visiting that environment.

There are many things to consider when completing this exercise, such as:

• How could the potential movement of people and/or animals affect the spread?
• What necessary hygiene practices are needed?
• What diseases could be an issue at these locations?
• What are the symptoms to watch out for?
• Do you catch these diseases from direct or indirect transmission? And how does this affect the risk assessment and code of practice?

How easily are infections spread?

The spread of disease through a population can be quite an abstract idea for students to understand. This is a fun game that students can play, to identify who started the outbreak of a disease and how far the disease spread through their class ‘population’.

STUDENT ACTIVITY

You will need:

• a test tube and dropper for each participant
• distilled water
• 0.1 M NaOH
• phenolphthalein solution, dissolved in alcohol and diluted in water (pH indicator)

CAUTION: Sodium hydroxide (NaOH) and phenolphthalein can irritate the eyes and skin.

HOW TO PLAY THE GAME:

1. Each student gets a test tube. All but one are half filled with distilled water. One is filled with the NaOH solution. With a large group of students (more than 30), two of the test tubes should contain NaOH solution.
2. Students move around the room and, when instructed, they put a drop of their fluid into the test tube of the person nearest to them.
3. Repeat until at least three exchanges have occurred.
4. When completed, put a drop of phenolphthalein in each test tube. If the fluid turns pink, the tube is ‘infected’ with NaOH.

QUESTIONS TO CONSIDER:

• How many people in the population (the classroom) have the infection?
• Who do you think gave you the infection?
• Look at the class data and determine who started the infection.
• How would this game change depending on the method of transmission?
• Why is determining how a disease spreads important?

The Barrier Game

The Barrier Game, available as part of the downloadable sexually transmitted infection resources on our website, can also be adapted to compare the spread of infection if certain control measures are in place.

FURTHER READING

Zoonotic diseases (zoonoses): guidance, data and analysis. http://microb.io/1VRIYQF. Last accessed 11 September 2015.