TB’s Unexpected Journey
September 1, 2014
Marine mammals brought tuberculosis to South Americans from Africa more than 1000 years ago.
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Transcript
Sea lion from Isla Ballestas, Peru. (Sara Marsteller/ASU)
BOB HIRSHON (host):
TB’s unexpected journey. I’m Bob Hirshon and this is Science Update.
Tuberculosis hitched a ride from Africa to South America with marine mammals before infecting humans there, according to a new study. Arizona State anthropologist Anne Stone was on a team that analyzed DNA from 1000-year-old human remains from Peru.
ANNE STONE (Arizona State University):
We discovered that the ancient South American human TB samples were most closely related to TB strains found in seals and sea lions. And that of course was a huge surprise, it was not what we were expecting.
HIRSHON:
Stranger still, she says this strain of TB probably first originated with humans in Africa.
STONE:
Humans got TB, we don’t really know from where, they then gave it to an animal; it got to seals and sea lions, it spread amongst them, including those that swam to South America.
HIRSHON:
Stone says hunting was likely to blame for the interspecies disease transmission. I’m Bob Hirshon, for AAAS, the science society.
