<P> By contrast, "Old World" diseases had a devastating effect when introduced to Native American populations via European carriers, as the people in the Americas had no natural immunity to the new diseases . Measles caused many deaths . The smallpox epidemics are believed to have caused the largest death tolls among Native Americans, surpassing any wars and far exceeding the comparative loss of life in Europe due to the Black Death . It is estimated that upwards of 80--95 percent of the Native American population died in these epidemics within the first 100--150 years following 1492 . Many regions in the Americas lost 100% . The beginning of demographic collapse on the North American continent has typically been attributed to the spread of a well - documented smallpox epidemic from Hispaniola in December 1518 . At that point in time, approximately only 10,000 indigenous people were still alive in Hispaniola . </P> <P> Similarly, yellow fever is thought to have been brought to the Americas from Africa via the Atlantic slave trade . Because it was endemic in Africa, many people there had acquired immunity . Europeans suffered higher rates of death than did African - descended persons when exposed to yellow fever in Africa and the Americas, where numerous epidemics swept the colonies beginning in the 17th century and continuing into the late 19th century . The disease caused widespread fatalities in the Caribbean during the heyday of slave - based sugar plantation . The replacement of native forests by sugar plantations and factories facilitated its spread in the tropical area by reducing the number of potential natural mosquito predators . The means of yellow fever transmission was unknown until 1881, when Carlos Finlay suggested that the disease was transmitted through mosquitoes, now known to be female mosquitoes of the species Aedes aegypti . </P> <P> The history of syphilis has been well - studied, but the exact origin of the disease is unknown and remains a subject of debate . There are two primary hypotheses: one proposes that syphilis was carried to Europe from the Americas by the crew of Christopher Columbus in the early 1490s, while the other proposes that syphilis previously existed in Europe but went unrecognized . These are referred to as the "Columbian" and "pre-Columbian" hypotheses . The first written descriptions of the disease in the Old World came in 1493 . The first large outbreak of syphilis in Europe occurred in 1494 / 1495 in Naples, Italy, among the army of Charles VIII, during their invasion of Naples . </P> <P> One of the influences related to the migration of people were cultural exchanges . For example, in the article "The Myth of Early Globalization: The Atlantic Economy, 1500--1800" Pieter Emmer makes the point that "from 1500 onward, a' clash of cultures' had begun in the Atlantic". This clash of culture transferred European values to indigenous cultures . For example, the emergence of private property in regions where there were little to no rights to lands, the concepts of monogamy and the nuclear family, the role of women and children in the family system, and the "superiority of free labor". An example of this type of cultural exchange occurred during the 1500s in North America . When these early European colonizers first entered North America, they encountered fence-less lands which indicated to them that this land was unimproved . For these Europeans, they were seeking economic opportunities, therefore, land and resources were important for the success of the mission . When these colonizers entered North America they encountered a fully established culture of people called the Powhatan . The Powhatan farmers in Virginia scattered their farm plots within larger cleared areas . These larger cleared areas were a communal place for naturally growing and useful plants . As the Europeans viewed fences as "hallmarks of civilization" they set about transforming "the land into something more suitable for themselves". In implementing their practices, the Europeans enslaved, murdered, and exploited indigenous populations . Furthermore, in cases of enslaved peoples (and in particular, enslaved Africans) the Europeans simultaneously implemented their value system while at the same time justifying enslaving people through a philosophy which reduced the enslaved people to property . Thus, the slave traders and some of the plantation owners used the concept of family to exploit and control the enslaved people . In other subtle ways, which had a large impact the cultural exchanges involved sharing practices and traditions . An example of this can be found in the tobacco industry . </P>

Which disease was exported from america to europe
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