Scientists studying ancient diseases have discovered one of the earliest examples of spillover – when a disease jumps from an animal to a human – and it happened to a Neanderthal man who likely became ill from slaughtering or cooking raw meat.
Researchers were re-examining fossilized bones of a Neanderthal that was found in a cave near the French village of La Chapelle-aux-Saints in 1908. The “Old Man of La Chapelle,” as it became known, was the first relatively Neanderthal skeleton complete to be unearthed and is one of the most studied.
More than a century after its discovery, its bones are still yielding new information about the life of Neanderthals, the heavily built Stone Age hominids that lived in Europe and parts of Asia before disappearing some 40,000 years ago.
The man, who must have been 50 or 60 years old when he died about 50,000 years ago, had advanced osteoarthritis of the spine and hip joint, according to a 2019 study.
However, during this reanalysis, Martin Haeusler, head of the Adaptation and Evolutionary Morphology Group at the Institute of Evolutionary Medicine at the University of Zurich, realized that not all bone changes could be explained by the wear and tear of osteoarthritis.
“Instead, we found that some of these pathological changes must be due to inflammatory processes,” he said.
“A comparison of the entire pattern of pathological changes found in the skeleton of La Chapelle-aux-Saints with many different diseases led us to the diagnosis of brucellosis.”
The study of these findings was published in Scientific Reports last month.
Brucellosis, common until today, can be acquired by humans through direct contact with infected animals, eating or drinking contaminated animal products or inhaling airborne agents, according to the World Health Organization (WHO).
Most cases of brucellosis are caused by unpasteurized milk or cheese from infected goats or sheep.
It is also one of the most common diseases known as zoonotic, which is transmitted from animals to humans and includes viruses such as HIV and the coronavirus that caused the Covid-19 pandemic.
Brucella has a wide range of symptoms, including fever, muscle aches and night sweats, Haeusler said. It can last from a few weeks to many months or even years.
The long-term problems it can cause are variable, but include back pain, inflammation of the testicles — which can lead to infertility — and inflammation of the heart valves, known as endocarditis, which Haeusler said is the most common cause of death from the disease. .
The paper said the case was “the first sure evidence of this zoonotic disease in hominid evolution.”
The disease has also been found in Bronze Age Homo sapiens skeletons, which date back to about 5,000 years ago.
Brucellosis is found in many wild animals today, and Haeusler said Neanderthal man likely caught the disease by killing or cooking an animal that had been hunted for prey.
Possible sources include wild sheep, goats, wild cattle, bison, reindeer, hares and marmots – all of which were components of the Neanderthal diet.
However, the paper said that the two large animals that Neanderthals hunted, mammoths and woolly rhinos, were probably not the hosts because their living relatives, the rhinos, had never had brucellosis detected.
Given that the man lived to what must have been a very old age for the period, Haeusler suspected that Neanderthals might have a milder version of the disease.
The “Old Man of Chapelle” played a significant role in misconceptions about Neanderthals being primitive Stone Age brutes, according to the Smithsonian Institute, a science and education complex based in Washington, USA.
More recent research suggests that Neanderthals were as smart as we are.
An initial skeletal reconstruction showed the man in a stooped posture, knees bent, and head thrust forward. Only later did scientists realize that the skeleton had a deforming type of osteoarthritis and was perhaps not a typical Neanderthal.
Haeusler said the study he published in 2019 showed that, even with the wear and tear of degenerative osteoarthritis, “Chapelle’s Old Man” would have walked upright. The man had also lost most of his teeth and may have been fed by other members of his group.
Reference: CNN Brasil