500-year-old Incan mummy had lung infection, probably TB
Studies of a 15-year-old Incan girl who was sacrificed on an Argentine mountaintop 500 years ago show that she had a lung infection when she died, most likely tuberculosis, researchers reported this week. Two younger children who died with her did not have an infection, they said.
The mummy, known as the Maiden, was discovered in 1999 about 25 yards from the summit of Llullaiaco, a high-elevation volcano in the province of Salta, Argentina, by archaeologists led by Johan Reinhard and Constanza Ceruti of the Mountain Institute in Franklin, W.Va. The Maiden and a 7-year-old boy and a 6-year-old girl had been sacrificed to Pachamama, the earth goddess, in the ritual of Capacocha. The area’s freezing temperatures, low humidity, anaerobic environment and presence of natural disinfectants led to remarkable preservation of the bodies, which are now on display at the Museum of High Mountain Archaeology in Salta, Argentina. The mummies are in airtight, self-contained capsules maintained at minus-20 degrees Celsius.
Testing ancient specimens for infections is a tricky buiness. Because DNA must be amplified, there is a danger of also amplifying extraneous contaminants. And even if a pathogen is present, it doesn’t necessarily mean the individual had an active infection.
Angelique Corthals, a forensic anthropologist at the John Jay College of Criminal Justice at City University of New York and her colleagues at SUNY Stony Brook took a different approach. They took tissue swabs from the mouths of the Maiden and the 7-year-old boy and analyzed the proteins that were present. The team reported in the journal PLoS One that the proteins present in the Maiden were characteristic of an active immune response to an infection. DNA analysis suggested that the Maiden was infected by a bacterium from the Mycobacterium family, which includes the TB bacterium, and CT scans suggested she suffered from a lung infection. Similar problems were not observed in the boy.
“Our study is the first of its kind since, rather than looking for the pathogen, which is notoriously difficult to do in historical samples, we are looking at the protein profile of the ‘patient,’ which more accurately tells us that there was indeed an infection at the time of death,” Corthals said. “Our study opens the door to solving many historical and current biomedical and forensic mysteries, from understanding why the plague of 1918 was so lethal to finding out which pathogen is responsible for death is cases of multiple infections.”