rome
Visitors are shown walking among ancient ruins at the Roman Forum, Oct. 28, 2016, in Rome, Italy. Sean Gallup/Getty Images

Malaria was responsible for killing millions of people in ancient Rome spanning centuries, scientists have determined after examining the DNA from 2,000-year-old human remains, according to a new study. Specifically, researchers tested the DNA from teeth on bodies that are 2,000 years old to reach their conclusion.

The find confirms the infectious disease's existence in ancient times and puts an approximate age on the scourge, according to Phys.org.

"Malaria was likely a significant historical pathogen that caused widespread death in ancient Rome," Hendrik Poinar, evolutionary geneticist and the director of McMaster's Ancient DNA Centre where the research took place, said.

The teeth examined were from 68 subjects previously buried at three cemeteries in Italy. From those teeth, scientists were able to remove DNA from "dental pulp" and link it to Plasmodium, a genus to which malaria parasite micro-organisms belong. The link confirmed the presence of malaria during the first century, at the earliest.

It has been long suspected that malaria, at least in part, contributed to the fall of the Great Roman Empire that at one time controlled lands spanning territory that ranged from Scotland to Africa for hundreds of years.

The CDC has defined malaria as "a serious and sometimes fatal disease caused by a parasite that commonly infects a certain type of mosquito," which then transmits the malady to humans. It can leave the person infected with "high fevers, shaking chills, and flu-like illness." Those same symptoms were confirmed via the teeth's DNA, though some questions still remain.

"There is extensive written evidence describing fevers that sound like malaria in ancient Greece and Rome, but the specific malaria species responsible is unknown," said Stephanie Marciniak, who did post-doctoral studies at the Ancient DNA Centre.

Another disease that blamed for pushing the Roman Empire to its demise is the plague, then-known as the Justinian Plague. The deadly bacterial affliction named for Byzantine emperor Justinian I is blamed for more than 100 million deaths between the 6th and 8th centuries, according to Live Science.