Map Monday, How human disease travels the globe

Human disease has taken many paths to travel the globe. Blown by winds and storms or carried on currents many early diseases found new homes via earth’s weather.  Some of these diseases may have taken their journeys in their native state, but quite a few hitched a ride on a carrier.  These parasitic diseases can be transmitted to humans by drinking contaminated water.  Giardiasis, commonly known as beaver fever, is caused by protozoa found in fecal matter from beaver, deer, sheep, and many other animals.  Other parasitic diseases come from eating contaminated food.  Many of these are caused by Helminths, which are worms such as tapeworms, flukes, and roundworms.

Still another group of infectious diseases use parasites to travel between their hosts.  An increasingly common example in my neck of the world is Lyme disease which is caused by bacteria delivered via the bite of infected deer ticks.  Another example making the news recently is the mosquito born Zika virus spreading through Central and South America.  As scary as those diseases are they’re not the worst. Malaria is still the most devastating bite delivered disease.  According to Nets for Life Africa’s statistics malaria infects over 207 million people annually and kills more than 600,000 of them. Ninety percent of the deaths occur in sub-Saharan Africa and most are children under five. As its name implies Nets for Life Africa is dedicated to supplying netting to prevent mosquito bites and save lives.

Civilization’s Impact

While not really unnatural, diseases have also taken advantage of the growth of human civilization to spread across the planet. Beginning in the late neolithic period and accelerating through the bronze and iron ages humans built large agricultural settlements. Situated near reliable sources of water (e.g., the Nile) these communities produced agricultural abundance and a rapidly growing population eventually growing into our first cities.

To serve the needs of their populations the cities traded and in many cases fought with other cities. People from hundreds and eventually thousands of miles apart began to interact. These interactions enriched both individual traders and their cultures. In addition to the products and ideas that the traders and soldiers brought home from their travels, they also brought new diseases. With the “discovery” and colonization of the new world by Europeans the process repeated itself with devastating results.  Along with slavery and exploitation of the native population the Europeans also brought their diseases. In the more lightly populated north 25-50% of the natives died. In the densely populated Aztec empire the population fell by 90 percent in just fifty years.

Having made it through that bit of grim data here’s today’s featured map courtesy of Lapham’s Quarterly. It shows the spread of Malaria, Leprosy, and Smallpox.

Sadly, I’m currently suffering from some unknown virus that’s been kicking my butt for almost a week.  I have no idea where it originated, but I’m doing my best to keep it bottled up.  I hope you are warm, safe, and well.

As always thanks for reading.

Armen

Note to Pay the Bills: As fiction series with strong connections to history, the Misaligned series does feature mentions of great calamities. Underpinned by Welsh mythology, the history of upstate NY and the basic elements of String Theory, the three book series explores the intersection of science and myth. Check out a summary of the series here or find links to purchase books here.