This past Monday – April 7th – marked the celebration of World Health Day, sponsored by the World Health Organization. The 2014 focus was on the spread of diseases around the globe.
The first World Health Day was celebrated in 1950, back when world population was 2.5 billion. Since the day’s inception, our global family has added an additional 4.5 billion individuals. Let’s take a moment and consider some of the ways population growth has impacted the ability of diseases to spread.
1. Population density and urbanization – Diseases spread more quickly among people who live in close proximity to each other. Currently, over 50% of the global population lives in urban areas. With more people living in dense conditions, there is more frequent contact between more individuals, allowing disease transmission to easily occur.
2. Migration and global travel – As it becomes more common for people to travel throughout the world, it also becomes easier for diseases to travel with them. An outbreak in one region that would have otherwise been contained can move into other uninfected regions when infected people travel or relocate to these areas.
3. Environmental degradation – Environmental challenges such as changing climate, can lead to the spreading of diseases, especially those that are vector-borne (or carried by a host). For example, the West Nile Virus is spread by mosquitoes (the vector). As the climate changes, the disease carrying mosquitoes are able to move into regions where they previously could not survive, thus affecting new areas. Additionally, as global temperatures increase, so do the conditions under which many of these carriers flourish.
The Population Education activity, Catch it if You Can, from Earth Matter’s Health unit can bring the challenge of disease transmission to light in your classroom. Students take part in a simulation that starts with a single individual being “infected” and the disease spreading throughout the room. After the simulation, you’ll discover how many students have become “infected” and challenge the class to figure out who was the original carrier.