Where did Columbus get the diseases?

Christopher Columbus, the famed Italian explorer, did not bring any diseases to any places he visited on his voyages. It was the Europeans, including Columbus and his crew, who encountered various illnesses and diseases that were indigenous to the Americas at the time. One of the most notable epidemics that occurred during this era was the exchange of diseases between the continents, which resulted in the spread of smallpox and measles from the Americas to Europe and Africa, along with other illnesses like malaria and yellow fever.