When Christopher Columbus arrived in the New World in the year 1492, he and his crew brought so many infectious diseases that more of the natives died than were born in the following years. Although it is hard to determine the exact numbers, we can assay that it was round about 40-50 million people. At that time (1519) there was an estimated number of 29,000.000 inhabitants of Mexico. By the year 1568 there were only 3,000,000. Of course, you cannot mark all of those fatalities up to disease, but it is fair to say that the introduction of new diseases in their environment was responsible for the majority. Why were their immune systems so defenseless to the attack of new bacteria? How did this effect their communities and lifestyles?

"Smallpox made its American debut in 1519, when it struck the Caribbean island of Santo Domingo, killing up to half of the indigenous population. From there outbreaks spread across the Antilles islands, onto the Mexican mainland, through the Isthmus of Panama and into South America." Some of the other diseases that followed this path were measles, plagues (bubonic and pulmonary), gonorrhea (from soldiers raping native women), mumps, typhoid, and cholera. Two African diseases, malaria and yellow fever, also came to Central American probably because of the ideal weather conditions in this region.

Prior to 1492, the Americas harbored relatively few infectious diseases. It is believed that the New World lived in virtual biological isolation from the rest of the planet due to the absence of domesticated animals and because of the path in which the Indians predecessors traveled. We know from origins of disease in Europe, that domesticated animals were to blame for the start of many epidemics. The New World lacked domesticated animals due to the extinction of large mammals, with which to draw from in the last ice age. Also, the remaining large mammals were not suitable for domestication for one reason or another. At the time of migration across the North American land bridge, cattle and sheep were still not utilized by society and therefore were not a cause for the spread of disease.

It is also believed that the path of migration across Bering Strait created a type of "germ filter" thanks to the harsh Arctic climate that killed off any bacteria or disease carriers such as worms or mosquitoes. In addition, the remoteness of clusters of migrants created a natural quarantine. By the time one group fell prey to an infectious disease they were unable to travel the great distances to infect other groups thereby extinguishing the disease. "While the New World had its native infections, including Chagas and Carrion's diseases, trichinosis, tapeworm, and perhaps syphilis, few were deadly, and none (with the possible exception of syphilis), seriously threatened whole communities of European colonists.

The impact that this biological isolation had on the conquest of the Americas is obvious. Along with the weapons and horses that the Europeans brought to conquer the New World came disease. This was by far the most horrific instrument of destruction.

Bringing with him only 1250 Spaniards and 8000 allied Tlaxcallan warriors, Cortes attacked the Aztecs which had pinned down the itinerant lieutenant left to govern them. His forces outnumbered and overcome by the Aztecs, he retreated and hours later Tenochtitlan was being ravaged by the previously unknown smallpox. It is believed that one of the soldiers picked up on the way back to Tenochtitlan by Cortes was suffering from smallpox. This disease wiped out Aztec leaders and warriors and subsequently cleared the path for Cortes to retake the city of 1.5 million. This victory was clearly not attributable to advanced weaponry, horses, or military genius but rather disease. Upon returning to the city, Cortes chronicler Bernal Diaz wrote, “I solemnly swear that all the houses and stockades in the lake were full of heads and corpses.

It was the same in the streets and courts...We could not walk without treading on the bodies and heads of dead Indians. Indeed, the stench was so bad that no one could endure it...and even Cortes was ill from the odors which assailed his nostrils.” Indeed it is from these first hand accounts, not skeletal remains, which provide us with the most evidence of destruction caused by disease. These authors include Las Casas, Father Acuna, and Diaz del Castillo.

One disease that may have originated in the New World is syphilis. Syphilis is named after a character in a poem written by Giraolamo Fracastoro in 1530 about a Greek shepherd Syphilis, who offended the goddess Venus and was punished. The term venereal disease comes from the name Venus.

Most information about the origin of syphilis supports the first theory, that syphilis was a New World disease and was transmitted sexually to the invading Spanish by Indian women. For example, most knowledge about syphilis after 1492 was mostly contained to the Spanish ports of Seville and Lisbon which were gateways to and from the New World. This would implicate that sailors coming from the Americas were treated here. There was consequently a leadership of Spanish and Portuguese physicians in the area of knowledge and therapy for syphilis. Also, there was no concrete name for syphilis in Europe before 1493. Symptoms that are similar to this form of venereal disease were widely referred to as leprosy, which was used to identify any disfiguring disease.

Mary Anne Winslow is a member of Essay Writing Service counselling department team and a dissertation writing consultant. Contact her to get free counselling on custom essay writing.