Its now official

Columbus brought sex disease to Europe from US, says new study
WASHINGTON: In 1492, Christopher Columbus sailed the Atlantic ocean to discover America, but when he returned from his historic voyages he brought with him a new disease to Europe, claims a new study.
The study, based on new skeletal evidence, suggests that Columbus and crew not only introduced Old World to New World, but brought back syphilis as well.
Syphilis is caused by Treponema pallidum bacteria, and is usually curable nowadays with antibiotics. Untreated, it can damage the heart, brain, eyes and bones; it can also be fatal.
The first known epidemic of syphilis occurred during the Renaissance in 1495. Initially its plague broke out among the army of Charles VIII after the French king invaded Naples.
but to sum it all, just read this (which is debatable but gives a nice clue)
http://en.wikipedia.org/wiki/Population_history_of_American_indigenous_peoples
facts and references
http://www.bbc.co.uk/history/british/empire_seapower/smallpox_01.shtml
Mann, Charles C. (2005). 1491: New Revelations of the Americas Before Columbus. New York: Knopf Publishing Group
"Native Americans of North America", Microsoft Encarta Online Encyclopedia 2006, Trudy Griffin-Pierce. Retrieved September 14, 2006
"Smallpox: The Disease That Destroyed Two Empires". Allicinfacts.com
"Stacy Goodling, "Effects of European Diseases on the Inhabitants of the New World"
"The peopling of the Americas: Genetic ancestry influences health". Scientific American
"Method and Theory in American Archaeology" (Digitised online by Questia Media). Gordon Willey and Philip Phillips. University of Chicago. 1958
I didn't know he came back. Damn those Americans :O(
I wonder how it got to Thailand ?
and in memory of their forefathers the americans during their testing and experimenting process came up with another disease called Aids or HIV in the 20th century for which they have not been able to find a complete cure yet
9o million? who did the census at the time?
Fact!
columbus and/or his crew. yes.
but they were very generous in return: they gave back smallpox and flu and other deseases that killed tens of millions of indigenous indians. 90 millions red indian in early 16th century, 10 millions in the mid 17th century. disease, war, slavery and forced labor.
So Columbus contracted the disease from the red Indians?
maize, potato, tomato, tabac, were also brought to the old world.
Another thing the US will be blamed for, as it's not enough for everything they have done already. JK :)
that's new? not at all. even officially it was known centuries ago.