According to the authors of a recent study, the modern strain of the facial herpes virus that causes herpes appeared about 5,000 years ago.
“We were able to determine that all variations of modern strains date back to a certain period at the end of the Neolithic, at the beginning of the Bronze Age,” explained Christiane Scheib, co-author of this study, published on Wednesday. in Science Advances.
So current herpes is only 5,000 years old, which is less than thought: “It’s a bit surprising because it’s been assumed that herpes evolved with humans for a very long time,” the ancient DNA and population expert told AFP. genetics associated with the University of Cambridge.
According to the World Health Organization, about 3.7 billion people are infected for life with the HSV-1 virus that causes facial herpes.
However, the history of this virus and how it spread remains little known, in part because old examples are hard to find.
Ms Scheib’s team examined the DNA of hundreds of people’s teeth from ancient archaeological finds. Only four of them were carriers of the herpes virus. It was by sequencing their genome that researchers determined when its modern incarnation appeared.
People are likely to live with herpes much longer. One can imagine that an earlier strain was probably circulating among humans when they first left Africa millions of years ago.
But it took a relatively recent time for it to take on its current form.
– Potential suspect, kiss…
How to explain this change?
The first version of the researchers: about 5,000 years ago, humanity was in a period of great migration from Eurasia to Europe, and this movement could be affected by a virus.
Another hypothesis is that the development of facial herpes in the Neolithic, found in ancient DNA, may have coincided with a new cultural practice, romantic and sexual kissing. According to Christina Scheib, “textual evidence of romantic kissing begins to appear in the Bronze Age,” which may have contributed to the spread of the virus.
The first known mention of kissing occurs in a Bronze Age manuscript from South Asia, suggesting that the practice may have passed to Europe later.
The facial herpes virus is usually passed from parent to child, but kissing would give it a new mode of transmission from host to host, the co-author of the study explained.
Kissing “is not a universal human trait,” she said, pointing to the difficulty of determining when the practice began and whether it is indeed linked to the spread of HSV-1.
Another co-lead author of the study, Charlotte Houldcroft, also from Cambridge, also pointed out that a virus like herpes develops on a much larger time scale than a virus like Covid-19.
“Facial herpes hides in its host for life and is only transmitted through oral contact, so mutations happen slowly, over centuries and millennia,” she said.
“Previously, genetic data on herpes date back only to 1925,” she noted, calling for more “in-depth research” to understand the evolution of viruses.
“Only genetic samples dating back hundreds or even thousands of years will help us understand how DNA viruses such as herpes or monkeypox, as well as our own immune systems, adapt to each other,” says this researcher.