Scientists have extracted malarial DNA from the ancient skeleton of a Roman child. The discovery is by far the oldest direct evidence of the killer disease and will help scientists trace the spread of mosquito-borne malaria across Europe. It also demonstrates the power of new genetic analysis techniques in studying ancient diseases.
Robert Sallares, who worked on the bones with Susan Gomzi at the University of Manchester Institute of Science and Technology, said: "This is the oldest hard evidence for malaria found so far. There are a lot of questions in medical history that could be answered from such ancient DNA."
The sample came from the recently excavated bones of a child who had been buried in the largest known infant cemetery in Roman Italy.
Malaria leaves no visible marks on the remains of its victims, but there were a number of clues that the toddler may have succumbed to its ravages.
Throughout the cemetery, archaeologists recovered the remains of decapitated puppies and a toad, supposedly relics of a magic ritual performed to ward off the disease.
Furthermore, all of the children in the cemetery appear to have been buried in just a few summer weeks in one year of the 5th century AD, possibly indicating a malaria epidemic in the Umbria region of central Italy.
As it is known that the malarial parasite gets into bone marrow during an infection, Sallares and Gomzi had to look inside the remains for telltale traces.
In research to be published in the journal Ancient Biomolecules , Sallares and Gomzi report that they were able to amplify fragments of ancient DNA by using a process called polymerase chain reaction.
Two independently recovered sequences were found to be almost identical to parts of the 18S rRNA gene of Plasmodium falciparum , the most deadly of the four parasites that cause malaria.
Scholars have long debated when this parasite first reached Europe. Drawing on Greek and Roman records, some have suggested that it may have reached the Mediterranean region just 2,000 years ago.
Sallares plans to repeat the work he did on the Roman child using human remains dating back to Bronze Age and Neolithic times.