Seals brought tuberculosis to Americas first

摘要

Blame the marine mammals. Seals and sea lions may have brought a form of tuberculosis to the Americas, centuries before the Spanish did so. There's little doubt that the Spanish carried measles, malaria, influenza and smallpox to the New World, when the conquistadores followed in Columbus's wake and began conquering the native peoples. Many assumed that they also brought Mycobacterium tuberculosis, the bacterium behind TB. But in the 1970s, 1000-year-old skeletons were found in Peru with apparent signs of TB. The Spanish didn't arrive until 1492, so how they became infected was a mystery. Johannes Krause of the University of Tubingen in Germany and his colleagues have taken a close look at three of the skeletons. Radiocarbon dating showed that they lived between 1028 and 1280.