Tuesday, July 22, 2008

I am Legend - The Sequel?

There has recently been another documented case of the Hendra virus in Australia (see Rachel Nowak’s “Could killer horse virus spread amongst humans?” In case you are not familiar with Hendra, it is a respiratory disease virus of horses, and is believed to be found exclusively in Australia. The disease has been known to jump to humans from horses, and there have been a few fatalities, but in general, this virus has not gathered a lot of media attention. What is interesting about this article is that Nowak reports that the new version of the virus may be slightly different than the previous versions. So why is this important?

In general, viruses are very specific in the species, and even the types of cells within a species, that it infects. However, the big problem with viruses is that most viruses have a high mutation rate. This means that the genetic material within the virus, which may be either DNA or RNA, changes at a faster rate. Some of these changes, especially when they are compounded over time, may cause the virus to change some of its proteins, and “recognize” new hosts. By the way, for you diehard creationists out there, these genetic changes are an example of evolution, and viruses have been doing this for millions, if not billions, of years. Some viruses mutate fast, others more slowly. Hendra virus has already done this, as it is appears to be derived from a virus found in fruit bats. Since fruit bats, horses, and us are all mammals, it appears that this virus has a special liking for warm-blooded creatures. For that reason alone, we need to pay attention to this one.

While I am glad to see that magazines, such as New Scientist, are reporting these outbreaks of Hendra virus, I am a little worried about how the general media is going to spin this story. If you remember, not too long ago the media picked up on scientific claims that scientists were predicting that the H5N1, aka “Avian Flu”, would leap to humans from poultry. With the release of “I am Legend”, many people believed that the apocalyptic end of the planet was at hand. When it didn’t happen that summer, or even the next, avian flu quickly faded from people’s minds, even though it has been increasing its range annually.

In fact, I still have friends of mine who claim that this was just another example of scientists blowing things way out of proportion. Some of them even try to use this logic to say that scientists are doing the same thing about climate change. This just shows a complete lack of understanding, and respect, for nature. Nature does not work on our timescale, nor does it even have a timescale. When these viruses mutate, as they have for millions of years, they may just develop the ability to infect a new species. And if that species is us, we are going to really wish that we had paid a little more attention to those over-reacting scientists.

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