Malaria in historic times

Analysis of 2,000-year-old human remains from several regions across the Italian peninsula has confirmed the presence of malaria during the Roman Empire, addressing a riddle about its pervasiveness in this ancient civilization[1].

Research managed to extract mitochondrial genomic evidence of malaria, coaxed from the pulp of teeth of bodies buried in three Italian cemeteries, dating back to the 1st to 3rd centuries Common Era. The genomic data is important, because it serves as a key reference point for when and where the parasite existed in humans and provides more information about the evolution of human disease.

“Malaria was likely a significant historical pathogen that caused widespread death in ancient Rome,” says evolutionary geneticist Hendrik Poinar. Even now malaria is a serious and sometimes fatal infectious disease that is spread by infected mosquitoes. It is responsible for nearly 450,000 deaths every year, the majority of them children under the age of five.

“There is extensive written evidence describing fevers that sound like malaria in ancient Greece and Rome, but the specific malaria species responsible is unknown,” says lead author Stephanie Marciniak. “Our data confirm that the species was likely Plasmodium falciparum, and that it affected people in different ecological and cultural environments.

Marciniak sampled teeth taken from 58 adults and 10 children interred at three Imperial period Italian cemeteries: Isola Sacra, Velia and Vagnari. Located on the coast, Velia and Isola Sacra were known as important port cities and trading centres. Vagnari is located further inland and believed to be the burial site of labourers who would have worked on a Roman rural estate.

They were able to extract, purify and enrich specifically for the Plasmodium species that is still known to infect humans. Extracting usable DNA was difficult, because the parasites primarily dwell within the bloodstream and organs, including the spleen and liver, which decompose and break down over the course of two millennia. In the end, the scientists managed to recover more than half of the Plasmodium falciparum mitochondrial genome from two individuals from Velia and Vagnari.

Literary evidence of malarial infection dates back to the early Greek period, when Hippocrates described the typical undulating fever highly suggestive of plasmodial infection[2]. Recent immunological and molecular analyses describe the unambiguous identification of malarial infections in several ancient Egyptian mummies[3].

[1] Marciniak et al: Plasmodium falciparum malaria in 1st–2nd century CE southern Italy in Current Biology – 2016
[2] Nerlich: Paleopathology and Paleomicrobiology of Malaria in Microbiology Spectrum – 2016
[3] Lalremruata et al: Molecular identification of falciparum malaria and human tuberculosis co-infections in mummies from the Fayum depression (Lower Egypt) in PloS One - 2013