If we could see millennia into the past, before people started forming societies, we would probably see them living isolated from one another—nomadic in nature. This lifestyle was a natural barrier to the spread of infectious disease. But, when they started clustering together, planting crops and staying in one place, infectious diseases surfaced and became lethal foes of humanity.
Cities grew, people started traveling for business, soldiers traveled for war, and they were all prime candidates to be carriers of disease. Just as in the recent past, when the Native American population was decimated by the diseases brought in by the Europeans, so too have populations in the past two thousand years been seriously affected by a disease’s introduction into their society. Bayer Pharmaceutical’s A Brief History of Infectious Disease illustrates this phenomenon:
430 BC, the plague of Athens resulted from 200,000 inhabitants and villagers fleeing into Athens when threatened by the Spartans. An unidentified infectious agent, from Ethiopia via Egypt, killed one-third of this population and ended the Golden Age of Athens.
166 AD, the Antonine plague was brought to Rome from Syria by returning Roman troops. The plague had been introduced to Syria from India by the marauding Huns. The plague (probably smallpox, bubonic plague, and measles) devastated the Roman Empire, killing 4–7 million people throughout Europe. The resulting social and political upheaval led to the collapse of the Roman Empire.
Circa 160 AD, bubonic plague (‘Barbarian boils’) carried by invaders from the north, led to the collapse of the Han Empire in China.
1346 to 1350, the bubonic plague pandemic started in China and moved along the trade routes through South Russia to the Crimea, which was besieged at the time. This bubonic plague killed more than one-third of the population of Europe.
1492, influenza, smallpox, tuberculosis and gonorrhea began when Columbus went to the Caribbean. The local inhabitants did not have immunity to these endemic European infections, and as a consequence, many of the people on the island of Hispaniola (where Columbus first set foot in the New World) died. Replacement of the population by African slaves introduced African infectious diseases such as malaria and yellow fever into the Caribbean and Americas, which, in turn, killed many European settlers.
1542, bubonic plague started in Egypt, killed 40 percent of the population of Constantinople, and spread all over Europe.
Early trading period, blackwater fever (malaria), yellow fever, bloody flux (dysentery), and worm infestations made trading with the continent of Africa difficult. The impact on travelers and soldiers was so severe that Africa was called ‘the white man’s grave.’
16th century, similarly devastating epidemics with European and then African infections – introduced by the Spanish into Central and South America. After the Spanish invasion, the population of Mexico decreased by 33 percent in 10 years and by 95 percent in 75 years.
As trade journeys lengthened, chronic infections such as tuberculosis and venereal diseases were introduced by European sailors to the Pacific islands, which lost 95 percent of their population as a result.
Present time, even during the past few decades, there has been a resurgence of epidemics such as Lyme disease and Rocky Mountain spotted fever in the United States and AIDS, genital herpes, and chlamydia worldwide.
This is one in a series of excerpts from PKIDs’ Infectious Disease Workshop. We hope you find the materials useful – the instructor’s text and activities are all free downloads.
Photo credit: AJC1