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Fwd: [RC] AZ - New, Fast-Evolving Rabies Virus Found - desertrydr1-----Original Message----- From: desertrydr1@xxxxxxx To: darste3@xxxxxxxxxx Sent: Thu, 7 May 2009 10:20 pm Subject: Re: [RC] AZ - New, Fast-Evolving Rabies Virus Found I work at a local health department in Environmental Health. Part of my job is screening animals that bite humans for rabies. I'm in WA state where the only type of rabies present has been the bat variant. In WA, we have very few cases of rabies. A couple back about 10 or 12 years ago where people died. A cat that bit someone a couple of years ago in Walla Walla tested positive for rabies. A horse tested positive in 1992, but there were some interesting circumstances involved that made it doubtful whether the testing was accurate, and it was my understanding at the time that the definitive test couldn't be performed, so they just said it was a positive and gave everyone post-exposure prophylaxis. That's it for the last 30 years or so for the state of WA. Rabies is know to be present in the bat population here. About one in 10 bats tested is positive--but only bats which are found in unusual circumstances (on the ground, a
lready sick, that kind of stuff) are tested. The estimate is that one in 100 bats in WA actually carries rabies. I get regular postings from the CDC on rabies issues, and am required to read and understand the Compendium put out by CDC every year, which details how potential rabies cases should be treated, and also includes other info on rabies.
Having said all that, the article that was posted is the first I've heard about any fast-evolving or cross-species rabies. I will definitely be checking it out at work tomorrow. I was bothered by some things in the article, and while I generally consider the National Geographic a pretty good magazine, one must consider that the author may not have the necessary virology background to understand everything that was said. I base this on the following passage: "Now laboratory studies at the U.S. Centers for Disease Control and Prevention (CDC) in Atlanta appear to confirm that the fox and skunk rabies viruses
are mutated forms of the bat strain. "We can see degrees of relatedness and patterns in their genetic codes," said Charles Rupprecht, chief of the rabies program for the CDC."
It has long been thought that there were the bat-variant rabies virus, the skuk-variant rabies virus, the raccoon-variant rabies virus, the fox-variant rabies virus, etc., that were totally separate variants of the virus. When I read the above passage, I read it as saying that the fox-variant and skunk-variant viruses appear to be mutated forms of the bat-variant rather than totally separate variants. That may be nothing new, just that science is now advanced enough in DNA and RNA research to show the relatedness. I'm not disputing the truth of the article, I'd have to do a bit more reading and study to satisfy myself in that regard. I'm just sayingthat people probably don't need to panic yet. The differences in recommendations regarding rabies vaccine have to do with whether or not rabies is endemic in the area and what animals are carrying it in the area, among other things. Here is WA, most vets don't have it on their recommended list because we only have the bat variant, and it isn't very common. Where the raccon or skunk variants are present, ie., terrestrial mammals that horses are more likely to come into contact with, it's probably high on the recommended list. Most people on the East Coast and into the midwest should vaccinate. My own personal guidleines for vaccinations are: If the person/animal gets the disease, is it likely to kill or seriously disable them? Rabies kills--almost everyone who gets it dies. West Nile Virus can kill or disable a horse or person. Influenza rarely kills. Rhinoviruses haven't in the past had high mortality. That's changed since the neurological form became more prevalent. Also there's the issue of abortions in pregnant mares. Tetanus is generally fatal, or at the least very debilitating. I would vaccinate for rabies if it were endemic in my area. I do vaccinate for West Nile, and will continue to do so. I vaccinate for tetanus and the other encephalitis viruses. I don't vaccinate for influenza as a general rule, because the vaccine has to be given several times a year, and the benefits, in my opinion, don't balance the costs. (I should mention that I have a couple of horses that HATE shots) I don't vaccinate for Rhino unless I have a pregnant mare. Strangles hasn't been a big issue around here, and most of my horses don't travel much. It's also a young horse's disease for the most part, and more of a PITA than a serious risk to life. jeri
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