Tuesday, June 17, 2014

Study: Human Ancestors Got Herpes From Chimps

Adults today are more likely to have herpes — oral or genital — than not. But where did this widespread disease come from?

To answer that question, you’ll have to go back millions of years, to a time before we were human.

New genomic analysis has found that oral herpes may have been around since before our split with chimpanzees happened about 6 million years ago. The virus then branched out and followed the evolution of hominids to become oral herpes, or herpes simplex virus 1 (HSV-1).

“The ancestor of all monkeys and apes had the herpes virus,” said study author and virologist Joel Wertheim of the University of California at San Diego. “When the host species lineage started to split, the viruses also formed new lineages.”

The virus responsible for genital herpes hit our ancestors later, likely jumping from proto-chimps to a now-extinct hominid — either Homo habilis or Homo erectus — about 1.6 million years ago. The ancient virus eventually gave rise to what is now known as herpes simplex virus 2 (HSV-2) in humans, commonly spread through sexual contact.

Because the chimpanzee herpes simplex virus found its way back into our lineage, we are the only primate species known to be infected with two distinct herpes simplex viruses. But how the transmission occurred from primate-to-hominid all those years ago remains a mystery.

“We can’t say whether the interaction that led to cross-transmission was physical aggression or sexual contact,” Wertheim said. “We just don’t know, but both are possible.”

Alternate means could have been through hominids hunting and eating the meat of proto-chimps or living with them in close quarters, said virologist Alberto Severini of the University of Manitoba, who was not involved in the research.


Full story here.
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