New evidence traces herpes virus back almost 5,000 years

Researchers have mapped the genetic structure of the herpes virus and, for the first time, traced its European origin back almost 5,000 years.

Genetic analysis of historic European samples of the human herpes simplex virus 1 (HSV-1), published today (Thursday) in the journal Science Advances, points to a common lineage in the late Neolithic period – around 2,000 BC – possibly linked to human migration from Africa into Europe and Asia.

Between 60% and 95% of the global adult population carry the life-long virus.

This new study, formed by experts from Tartu and Talinn universities in Estonia; Leicester, UCL, Cambridge, and Aberdeen in the UK; Udmurt State University in Russia; plus the Institute of Molecular Biology and Pathology in Italy and both Alan Turing (UK) and Max Planck (Germany) institutes, analysed samples between the 3^rd Century to 17^th Century CE.

Previously the oldest HSV-1 genome was isolated from an individual living in New York in 1925. But due to the nature of laboratory testing of viral structures – by growing the virus in multiple ‘passages’ – this sample may have evolved at a higher rate than would have been seen in humans.

The research team therefore sought older, previously untested examples of the virus from individuals who lived across Europe.

The oldest DNA sample came from an adult male excavated in Russia’s Ural Mountain region, dating from the late Iron Age around 1,500 years ago.

Two further samples were local to Cambridge, UK. One was a female from an early Anglo-Saxon cemetery a few miles south of the city, dating from the 6^th Century to 7^th Century CE. The other was a young adult male from the late 14^th Century, buried in the grounds of medieval Cambridge’s charitable hospital (later to become St John’s College), who had suffered appalling dental abscesses.

The final sample came from a young adult male excavated in Holland: a fervent clay pipe smoker, most likely massacred by a French attack on his village by the banks of the Rhine in 1672.

After isolating the HSV-1 virus from the samples, researchers then sequenced its genome up to nine-and-a-half times with paired human genomes and used the resulting data to track the evolution of herpes across Europe, and estimate when it likely first appeared on the continent in its modern form.

It is believed that the very earliest evolutionary origins of HSV-1 date back more than 6 million years, before modern humans walked the Earth.

Researchers also hold historical evidence of the herpes virus, with early Roman Emperor Tiberius said to have banned kissing in Ancient Rome due to the prevalence of cold sores among the population.

Dr Sarah Inskip, UKRI Future Leaders Fellow at the University of Leicester, performed the osteological analysis of the samples for the study. She said: “It was exciting to find evidence of the virus in teeth of skeletons from Medieval Cambridge as we were not looking for it. It really shows the importance of genetic screening of archaeological skeletons for a host of pathogens as it significantly improves our knowledge of the evolutionary history of diseases, and this is highly relevant for understanding disease patterns today.”

Dr Christiana Scheib is a Research Fellow at St John’s College, Cambridge and leads the Ancient DNA research group at the University of Tartu, Estonia, and is also corresponding author for the paper. She added: “Every primate species has a form of herpes, so we assume it has been with us since our own species left Africa.

“However, something happened around five thousand years ago that allowed one strain of herpes to overtake all others, possibly an increase in transmissions, which could have been linked to kissing.”

‘Ancient herpes simplex 1 genomes reveal recent viral structure in Eurasia’ is published in Science Advances.