The herpes virus behind cold sores may have first spread widely around 5,000 years ago, possibly due to the rise in popularity of kissing at the time, researchers say.
“Every primate species has some form of herpes, so we assume it’s been with us since our own species left Africa,” co-senior author Christiana Scheib, research associate at St John’s College, University of Cambridge and director of Ancient DNA -Laboratory at the University of Tartu in Estonia said in a expression (opens in new tab). “However, something happened about five thousand years ago that allowed one strain of herpes to overtake all others, possibly an increase in transmissions that could be linked to kissing.”
At least that’s the theory. Charlotte Houldcroft, co-senior author and leader of the Virus Genomics group in the Department of Genetics at Cambridge University, said The Guardian (opens in new tab) that more evidence is needed to solidify the link between Bronze Age make-out sessions and modern day herpes. “Kissing is one of those behaviors that doesn’t petrify well,” she said.
Herpes simplex virus 1 (HSV-1) is a type of herpes that most commonly causes cold sores, although it can also cause genital herpes World Health Organization (opens in new tab) (WHO). The lifelong infection often causes no symptoms but can sometimes result in painful blisters or open sores at the site of infection. The latest estimates suggest that about 3.7 billion people under the age of 50, or about 67% of that age group, have HSV-1 infection, and most people contract the infection in childhood or early adulthood through exposure to virus-carrying virus draw in saliva, after which Centers for Disease Control and Prevention (opens in new tab) (CDC).
In a new study published in the journal July 27 scientific advances (opens in new tab)researchers suspect that the modern HSV-1 virus outstripped other herpes variants during the Bronze Age after people from the steppe grasslands of Eurasia traveled to Europe in mass migrations.
For the study, the researchers analyzed traces of herpes viruses DNS found in the remains of four individuals excavated in Britain, the Netherlands and Russia. The oldest remains unearthed in Russia’s Ural region were around 1,500 years old, and the youngest found in the Netherlands were around 350 years old.
Before the study, the oldest herpes genomes ever found dated only to 1925, Houldcroft said in the statement.
The researchers examined the dental roots of these individuals to “dust” for genetic “fingerprints” of herpesviruses. Unlike bones in the body, teeth do not regenerate, meaning they never replace their old cells with new ones. For this reason, and because viruses can enter teeth through the bloodstream, teeth can provide a cumulative record of pathogens that a person has encountered. Live Science previously reported.
By comparing the newly discovered herpes DNA with that of 20th-century herpes viruses, the researchers were able to estimate the mutation rate of the virus and thus understand the evolutionary history of the pathogen. Based on this analysis, they determined that HSV-1 probably arose around 5,200 years ago, more or less a few hundred years. This may have coincided with the Bronze Age migrations to Europe, during which the practice of kissing romantically and sexually probably became more widespread, the authors posit.
Although some Stone Age figures could be interpreted as couples embracing, “the earliest known written record of kissing is a Bronze Age manuscript from South Asia,” the study authors wrote. The armies of Alexander the Great could end the custom around 300 BC. to the Mediterranean Sea, and then in the first century AD [Roman] Emperor Tiberius is said to have tried to ban kissing on official occasions to stop the spread of disease (unclear if the disease was herpes),” the authors wrote.
This increase in kissing likely helped HSV-1 spread and gain prominence over other circulating herpesviruses, the authors argue. “If you suddenly have a group of people kissing, which wasn’t universal human behavior, that’s an additional way of spreading the virus,” Houldcroft told The Guardian. (According to a 2015 study published in the journal, even in modern cultures, romantic kissing is not universally practiced American anthropologist (opens in new tab).)
But even this is just a theory. While romantic kisses became more common during Bronze Age migrations, it’s unclear how much of an impact these kissing sessions would have had on the evolution of herpesviruses. The authors note that earlier in history most people likely contracted herpes from family members in childhood, similar to the way most people today contract HSV-1 from childhood rather than from romantic kisses.
Originally published on Live Science.
‘Cold sore’ virus may have gained prominence thanks to Bronze Age smooching Source link ‘Cold sore’ virus may have gained prominence thanks to Bronze Age smooching