It’s largely gone unnoticed, because this virus is very similar, or related to, a previously described virus in horses. The equine herpes virus 1 is a virus of domestic horses and is present in many horse populations throughout the world. This virus [the one we had here] kind of went under the radar for a number of years, because it’s very similar to that virus.
It was presumed to be just a sub-strain of it, but now we know through more advanced genetic analysis that it is a separate species of virus. It may have — this is just speculation — but it may have arisen from the equine virus many years ago.
There are certain viruses that can infect almost any type of mammal — for example, the rabies virus. For a herpes virus, this is a unique type of virus, because it’s now infected animals in three different orders, which is very unusual.
It’s infected artiodactyls, which include host stock in ruminates — for example, giraffes and gazelles. It’s infected equids like the zebras, as well as onager, and now it’s infected an ursid, which is the polar bear. Those are three widely different taxonomic groups of animals. In all cases, infection has been naturally occurring. That led to a lot of people being interested in this virus as a potential threat to many animals as well as people. So as some researchers have done — in Japan — [they] have done inoculation studies and found that the virus can also infect rodents, cats, dogs, goats, sheep, and primates.
[Infection in humans] has never been documented, but that is a potential worry. And that is a very primary focus now of the National Institutes of Health, developing programs and funding for looking at viruses that have the potential to become zoonotic or to infect people. And much of that research has been driven by the recent outbreaks of SARS and avian influenza, the highly pathogenic influenza, both of which have been extremely costly and detrimental to human health. Now the NIH is really focused on How can we find viruses that are on the verge, or have the potential, of becoming zoonotic? And this is one of the types of viruses that they would be very interested in. — Matt Potter