A person with a cold sore on their mouth
The modern strain of the facial herpes virus, which causes cold sores, dates back around 5,000 years, according to the authors of a recent study.
We were able to determine that the variations of modern strains all date back to a certain time in the late Neolithic, early Bronze Age, explained Christiana Scheib, co-lead author of this study published Wednesday in the journal Science Advances.
Current herpes would therefore only be 5000 years old, a younger age than imagined: This is a bit surprising, because it has been assumed that herpes co-evolved with x27;human for a very long time, this expert in ancient DNA and population genetics, linked to the University of Cambridge, told AFP.
Among the About 3.7 billion humans are infected with the HSV-1 virus that causes facial herpes for life, according to the World Health Organization.
L& #x27;History of this virus and the way it spread remains little known, however, in particular because it is difficult to find old examples.
Ms. Scheib's team examined DNA from the teeth of hundreds of people from ancient archaeological finds. Only four of them carried the herpes virus. It was by sequencing their genome that the researchers determined when its contemporary incarnation appeared.
Humans have probably been living with herpes for 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 until relatively recent times for it to take on its current form.
How can this change be explained?
Researchers' first theory: About 5000 years ago, humanity was in a period of great migration from Eurasia to Europe, and this movement could have affected the virus.
Another hypothesis: the development of Neolithic facial herpes detected in ancient DNA may have coincided with a new cultural practice, the romantic and sexual kiss. Textual evidence is beginning to emerge in the Bronze Age about romantic kisses, which may alter how the virus spreads, according to Christina Scheib.
The earliest known mention of kissing is in a South Asian manuscript from the Bronze Age, suggesting that the practice may have passed to Europe later.
The facial herpes virus is usually passed from parent to child, but kissing would have given it a new way to jump from host to child another, the study co-author stated.
Kissing is not a universal human trait, she said, pointing the difficulty of determining when this practice began or whether it is definitely linked to the spread of HSV-1.
The other co-lead author of the study, Charlotte Houldcroft, also from Cambridge, further pointed out that a virus like herpes evolves on a scale of much longer 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. #x27;to 1925, she noted, calling for more in-depth investigations to understand the evolution of viruses.
Only genetic samples dating hundreds or even thousands of years will help understand how DNA viruses such as herpes or monkeypox, as well as our own immune systems, adapt to each other, according to this study. researcher .