Study shows TB spread to pre-Columbian South America by seals, sea lions

A recent study found evidence that seals and sea lions likely spread tuberculosis to humans in South America before the arrival of Europeans.

The research, published in Nature, found that seals and sea lions probably contracted the disease from humans in Africa and transported it across the Atlantic.

"Our results show unequivocal evidence of human infection caused by pinnipeds (sea lions and seals) in pre-Columbian South America," Anne Stone, a professor at the Arizona State University School of Human Evolution and Social Change and a researcher on the project, said. "Within the past 2,500 years, the marine animals likely contracted the disease from an African host species and carried it across the ocean to coastal people in South America."

The researchers said that the implications of the study include a better understanding of the speed and process of adaption when a disease changes hosts, which could help when investigating other diseases that are transmitted between species, including other strains of tuberculosis.

"Tuberculosis is a disease that is on the rise again worldwide," Jane Buikstra, the director of the Center for Bioarchaeological Research and an investigator on the study, said. "This study and further research will help us understand how the disease is transmitted and how the disease may evolve."