Lately, there’s been a lot of news about viruses that hang around a whole lot longer than you would imagine. Modern human DNA still contains traces of a Neanderthal virus, and scientists recently recovered strands of an ancient plague from an old tooth. I know scientists learn from these ancient bugs, but I have to admit that I’ve been wondering why they’d focus on something so old when there are so many debilitating illnesses that wreak havoc on modern man. I found the frightening answer in a story about yet another virus that’s been revived by scientists. This one has been hibernating in the Siberian tundra.
The Proceedings of the National Academy of Sciences published a study by French scientists who thawed out a virus that had been frozen 98 feet below the surface, well into the permafrost of Siberia, for some 30,000 years. That means the disease would have been active around the time of Neanderthals and woolly mammoths. Despite its long nap, the virus, Pithovirus sibericum, grew in a petri dish and eventually infected an amoeba.
As viruses go, this one is particularly nasty. Your average flu virus contains eight genes, while Pithovirus sibericus has 500. In fact, it’s so big that right now it belongs in its own category in the family of Megaviridae. The good news, though, is that Pithovirus sibericus can’t infect humans or animals, just one specific type of very lucky amoeba.
The experiment suggests that some of the viruses and other pathogens out there that we thought were eradicated might not be, they might only be frozen. This also means that thawing due to climate change could pose serious health risks in the future. So could drilling. Excavating in the tundra or Arctic could inadvertently uncover these viruses, giving them the opportunity to ravage humankind once again. I would have thought that deep-freezing a virus for tens of thousands of years would kill it, but apparently that’s not the case. They’re tough little bastards, and the lead author of the study believes that “we could eventually resurrect active infectious viruses from different periods.” Fantastic.
Want more good news? It turns out that smallpox behaves similarly to Pithovirus sibericum when it comes to replication, so the resurgence of such viruses is “no longer limited to science fiction.” Well. Good thing Google’s on the case, I guess. This also makes me wonder whether any viruses exist in the frozen Martian landscape, just waiting for a human (or a rover) to thaw it out.