Cleaveland: The microbial conquest of the New World

On Oct. 12, 1492, a sailor in the three-vessel convoy commanded by Christopher Columbus sighted land. Later that day, Columbus set foot on San Salvador Island in the Bahamas. Masterful navigation had guided the convoy from its Sept. 6 departure from the Canary Islands to landfall in the Caribbean Sea. A 300-year period of exploration, colonization and exploitation followed.

In my early school years, we celebrated Columbus for bringing "civilization" to lands inhabited by backward natives. A collegiate course in American history did not challenge this narrative. The designation of Columbus Day as a national holiday in 1937 seemed a natural commemoration.

Columbus' second voyage included 17 ships, hundreds of men and a small contingent of armed cavalry. Livestock, brought on this and subsequent voyages, served as reservoirs for diseases that would devastate native populations.

Historian Roy Porter paints a somber picture of the voyages by Columbus and later explorers "... the biological consequences were devastating, unleashing the worst health disaster there had ever been and precipitating the conquest of the New World by the Old World's diseases."

Inhabitants of the Americas had crossed a land bridge from Asia to Alaska before 10,000 B.C. Subsequent melting of glaciers submerged the connector, isolating the inhabitants who multiplied and relentlessly spread southward through the Americas. The native population dealt with a variety of diseases, including tuberculosis and parasitic infections. They had no immunity to diseases that accompanied Columbus and subsequent European explorers and adventurers.

Influenza, likely brought to the Americas by pigs imported on the second voyage of Columbus, wiped out most of the native population on Hispaniola (Haiti and Dominican Republic). The disease would ricochet around the Caribbean Islands and reach the mainland in recurring outbreaks.

Measles and typhus followed. Some island populations were decimated. Survivors were often too weak to work, leading to starvation from unworked crops.

Smallpox had afflicted European populations for centuries. Periodic epidemics would kill tens of thousands. Survivors had immunity against further infection. Soldiers and sailors who were infected with milder forms of smallpox brought the disease to Caribbean islands around 1518. It quickly spread through native populations.

Smallpox helped Spanish invader Hernan Cortes defeat the Aztec empire in 1821. The disease preceded the Spanish force as it worked its way into the interior of present-day Mexico. Three hundred Spanish troops besieged the main city of Tenochtitlan (on the site of today's Mexico City). During the siege, smallpox wiped out most of the estimated population of 300,000, including military leaders. Survivors were too weak to fight when Cortes led his small force into the city. Spanish domination of Mexico followed.

Smallpox softened resistance of the Inca Indians when Francisco Pizarro invaded the west coast of South America, in what is present-day Peru, in 1533. The largest Incan city fell with little opposition because the defenders had either died or become weakened by small pox.

Because disease had reduced the numbers of native workers, Spanish settlers imported slaves from Africa beginning in 1501 to raise crops and to work in silver mines. The slaves brought malaria and yellow fever to the New World. Both diseases took a steady toll for the next four centuries.

Final tallies of deaths from imported disease cannot be calculated. An estimated one-third to one-half of the native population of the Caribbean and Americas is believed to have died as a consequence of these illnesses.

Should Columbus Day simply honor the great navigator and explorer? Or should the day promote reflection of the human toll of European colonization of the New World?

Contact Clif Cleaveland at ccleaveland@timesfreepress.com.

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