La Jornada: Malaria, and not poisoning, caused the death of the Medici brothers

A recent genetic analysis of the skeletal remains of the Medici brothers, from 16th century Italy, has provided new data on the cause of their death and refutes centuries-old rumors about a poisoning scandal in one of the most influential families in Renaissance Europe.

Recent findings show that both brothers became infected and succumbed to the malaria-causing parasite.

The study sheds light on the spread and evolution of malaria in central Italy during the Renaissance and later, according to the researchers.

Published in the magazine iSciencethe study offers conclusive evidence against persistent speculation that Francesco de Medici was poisoned, scientists say.

“Our study is an excellent example of how we can use advanced ancient DNA laboratory methods to reconstruct the history of this deadly pathogen,” said Serena Tucci, associate professor of anthropology at Yale.

“It also generated data that can inform current and future research on malaria, which remains a deadly disease that affects millions of people around the world,” said Adalgisa Caccone, another author of the Yale study.

Malaria was endemic in central Italy until the 20th century, when eradication campaigns eliminated the disease from the region.

Historical accounts note that Cardinal Giovanni de Medici died at age 19 after his family, including his mother, Eleonora of Toledo, and younger brother, Garzia, contracted malaria during a trip to the Tuscan coast in 1562, where the marshes were known to be a hotbed of the disease.

Then, in 1587, Francesco de Medici and his wife, Bianca Cappello, visited the Medici family villa in Poggio, located in the middle of swampy rice fields where mosquitoes proliferated.

The couple died on consecutive days after suffering intermittent fevers compatible with malaria.

However, after their rapid deaths, rumors spread that Francesco’s brother and rival, Cardinal Ferdinando de Medici, had poisoned them.

“At that time, both were diagnosed with symptoms, such as intermittent fevers, compatible with malaria,” said Valentina Giuffra, co-author of the study.

In the study, scientists collected DNA from four rib samples of the Medici brothers, buried in the Medici Chapels, mausoleums inside the Basilica of San Lorenzo in Florence, Italy.

Researchers found a new strain of Plasmodium falciparumcausing the most lethal form of human malaria, in the bones of Giovanni de Medici, descendant of the dynastic family that dominated politics and banking in Tuscany.

They found molecular traces of Plasmodium falciparum and of a second kind, Plasmodium malariaein the remains of his brother Francesco de Medici, who also succumbed to malaria.

“This genetic analysis confirms historical accounts as well as previous research. We can now say with scientific certainty that malaria, and not poisoning, was the cause of the death of Grand Duke Francesco de Medici,” stated Dr. Giuffra.

The finding that Francesco de Medici had traces of two species of malaria parasites suggests that both were probably spreading through Europe at that time.

However, researchers say more genetic testing is needed to confirm this.

“The study of ancient DNA offers us the opportunity not only to diagnose malaria in the remains of individuals from the past, but also gives us a perspective to understand the evolution of malaria species, which can help scientists better understand how the pathogen adapts over time,” stated Alexander Ochoa, co-author of the study.