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The Truth about Bats and Blogs

Sunday, March 21, 2010


When I was a freshman at Harvard, a wise alum gave me a piece of advice that I have carried with me throughout my life. "No matter how much you think you know about a subject," he warned, "someone who knows a whole lot more about it may be standing right behind you." For someone who's outspoken and loves to pronounce upon what little she knows, that's a potent life lesson, one that I learn again and again and again. Lest you be tempted to think it happens more at Harvard, I can attest that there are experts lurking in every corner. Here's a letter I got from Dr. Timothy Winship, who has been quietly reading my blog, but who couldn't get past Google's comment guard dogs to post this comment:

"As a professional virologist, with a background in animal viral disease, I appreciated your post about rabies in bats which contained a great deal of accurate information. A few points to clarify, though: the figure of 0.5% for rabies infection incidence in bats is cited quite a lot, but in fact this is based on a very limited sampling (it's surprising how little research on infection of bats with bat strain rabies viruses there is!). It probably isn't true, but what you must bear in mind is that 0.5% is NOT a low incidence given the number of animals we are talking about. That's one in two hundred animals, or 5 in 1000, or 50 in 10,000 and so on.

Because bats may roost in colonies of hundreds or thousands, this presents a problem. Dr. Winship continues:

"Also, most of the information we have regarding the pathology of rabies in bats is from laboratory infection of bats with canine strains of virus. Under those conditions bats develop a fairly typical pattern of disease seen in other mammals. However, very little is known about what happens when bats are infected with bat strains of the virus, and in particular how bats infect other bats. Your statement about not knowing the incubation period of the disease in bats is quite true but covers a lot of unknown ground! The actual level, or potential for asymptomatic carriage, of bat strain virus in bats is not known, i.e. I can't find any evidence in the scientific literature that anybody can tell you that an asymptomatic bat can't transmit rabies. Certainly these kinds of viruses, under the right conditions, can establish very persistent latent infections. I personally don't agree that we know that an asymptomatic bat cannot transmit the disease.

And as I think about it, who knows enough about normal bat behavior to say what's normal and what might be abnormal? Not me! Bats are bizarre little things.-JZ

Dr. Winship continues:

"The evidence from bite exposure records held by the CDC is disturbing--most cases are not from animals aggressively attacking and biting humans, i.e. acting rabid... You are right about health department records of bat testing being skewed towards unhealthy animals, but the statistics do tell us something about the geographic distribution of the disease, at least. If you haven't already seen it, here are the numbers and distribution of animal found in Ohio last year. It's also important to bear in mind that while the number of human rabies cases acquired within the US yearly is very small (averages something like one per year) the number of exposures is quite a lot higher (last I saw about 50 per year in Ohio). And, last I looked the cost of post-exposure prophylaxis was on the order of $12,000 per person. (Which makes the $700 pre-exposure shot series sound cheap). Anyway, I'm glad you're being careful. I enjoy your blog greatly and want to keep doing so for a long time! Thanks again--sorry this was so long-winded. "

This letter, like so many of your comments and emails, hit just the right note. I'm grateful to have knowledgeable and caring people reading this blog, and I'm doubly grateful when they speak up and add their own experiences to the discussion, holding up a light for us all to see by. That's one of the big reasons I can't seem to give it up--I learn so much.

Spurred by Dr. Winship's letter, I rooted around a bit to find out more about a case I'd heard about, of a Missouri man who'd had a bat get into his home in the Ozarks in October 2008 and gotten bitten by it. It's always tempting to think that someone dumb enough to handle a bat somehow has it coming to him if he gets bitten, but watching this video should persuade you otherwise. Here was a bat (the video shows file footage of a little brown, but it was more likely a big brown) that got into the living space of a home, acting normal. In the course of dealing with it, this good, intelligent, caring, wildlife-loving person allows it to climb up his coat. (Sound like something the Science Chimp might do?) It gets up next to his neck, he turns his head, hunching up his shoulder as you would; the bat gets frightened, squeezed by the coat, and nips him on the ear. Concerned, he keeps it around for a couple of days, but it acts normal and he decides to release it. His family is concerned, too, even teases him about getting rabies, but it just doesn't seem possible that anything bad could happen. It's just a bat, and people get all hysterical about bats.

Five weeks later, he falls ill, and dies painfully--all the more tragic, because his death could have been prevented by a series of injections administered immediately after the bite.

Here's the deal. If you get bitten by a bat or other rabies-vector species, you MUST get it tested and see a doctor immediately. Its brain tissue must be examined for the telltale ovoid bodies of the rabies virus. If it tests positive, you'll be given a series of shots, and you won't die. If you don't get it tested, and decide to take your chances, your family could be talking about you on a heartbreaking video like this one.

So, as enamored as I am of Dee Dee, and adorable and apparently healthy as she is, her welfare and her life is distinctly secondary to mine and my family's. The possibility that she may have a latent infection is small, but it's present, and we simply don't know enough about bat strains of rabies or normal bat behavior to say with any certainty that an asymptomatic bat is safe to handle. It's not. So if I mess up, and Dee Dee bites me, that's it. She dies, that I may live. Long sleeves and gloves for me, always, and nobody else handles her, ever.

Dr. Winship left me with a link to a terrific U.S. Geological Survey publication, available free and readable as a pdf file, that he describes as "the very best review of bat rabies I have ever found, and...recent as well." I concur wholeheartedly. Despite its foreboding title, Denny Constantine's "Bat Rabies and Other Lyssavirus Infections" is a great read.

Download it here.

Thank you, Dr. Winship, for bringing this issue into crystal-clear focus for me and my readers. It's good to have people like you, standing right behind me.

17 comments:

Kudos to you: Your blog has some top notch readers. I was fascinated by Dr. Winship's comment.

Mary says Blogger won't let her comment, so here's hers:


"I come here every day because of this. What I've learned from you for three years is immeasurable. I appreciate your readers, too!

Your honesty moves me. I believe there is always someone nearby who can pull the rug from under you without a moment's notice. Always believe it and you'll never be unprepared for anything ;-)

Please be careful. I know you will."

Julie, you keep talking about bites, but I'm still not 100% clear about the possibility/probability of virus transfer from urine/feces/saliva contact -- I'd always heard that was possible. I think one of your prior posts indicated it unlikely, but there again how much do we really know on that? (Since you've been vaccinated probably not a major concern for you, but only for other family members.)

I salute you as a person whom even more knowledgeable people can sneak up on. You're an attractive force.

Cybertthrush, we can look at bat urine and feces under a microscope, and see if the virus is there, and as far as I know we won't find it. If people could get rabies from bat urine and feces we'd be in deep doo-doo. Spelunkers wade through the stuff. People with bat colonies in their attics would be at great risk. I've had bat guano and urine rain down on me and all my belongings as I (sorta) slept in Guyana. The rabies virus is fragile. As far as I know it's shed only in saliva, and "if it's dry, it dies."

In another part of his letter, Dr. Winship said, "Someone in in the blog mentioned transmission from urine--might want to ask about that, as I have never seen any evidence for it. Something new? Certainly a lot more potential for human exposure to bat urine than saliva. Again, remember those huge bat colonies in Texas!"

Somebody may well correct me, but I think you have to get saliva from an actively infected animal on mucous membranes or in an open wound to contract the disease.

And I'm sorry to say I *haven't* been vaccinated, which is what prompted Dr. Winship's letter. I don't have a spare $700 lying around. If everyone sent a dollar... :-)

sorry, my bad... (bad aging memory that is); was thinking your prior post mentioning price was becuz you HAD gotten it. DOHH!!
and of course the other explanation makes sense... in my area raccoons, foxes and others often have rabies outbreaks, and they too of course leave excretions through the woods and grass that would be dangerous if it were that simple.
Carry on... (I'll go back to thinking about vomiting vultures now)

Dear Zick,
In the course of having a bat bite about two years ago I have three tidbits to offer:
1) The teeth were so tiny that it was several hours before I realized that the bite had pierced the skin, and even then it was barely noticeable.

2) The position of the Public Health Dept. of the State of Rhode Island and Providence Plantations is that if you even awake and there is a bat in your room, you should get the rabies series. They say that the bat form of rabies is highly infectious.

3) In addition to the rabies series itself, you also get rabies immune globulin in amount proportional to your body weight at the same time as the first rabies shot. Preferably this is to go in the area of the wound, but in my case I needed fifteen syringe-loads so they stuck it in my behind. They called in a second person so I was getting two shots at once, and I asked why. The answer was "You can't hurt in two places at once." And you know what? It's true. Shot #15 hurt a good deal more than any of the previous pairs, and of those pairs, the side which was consistently a quarter second ahead consistently hurt a bit more then the lagging side.
Yours,
David

Doc's letter was great.
And to tag on to David's note about the Rhode Island protocols for waking up with a bat in the room. Florida's is about the same.

Repeating himself from an earlier post... just be careful if you must do this batgirl thing.

Mary's comment is right on, your Blog teaches us so much. This series about coexisting with bats is excellent information. Once again, we learn appreciation for nature, as well as reverence and respect. Thanks Julie !

I think it was my comment that mentioned that there was some evidence of transmission through bat urine. I swear I remember reading an article which talked about aerosolized bat urine in caves being thought to be a possible source of exposure in certain instances; a quick literature search did not turn anything up so it is possible I dreamt it. I will keep looking and post if I can find the info. At any rate, unless you are a serious spelunker, I doubt that it is relevant information. Sorry if I misremembered!

What a perfect quote and yes, definitely a life lesson to which I know I should pay more attention.

Many thanks to Dr. Winship! Many thanks to the Science Chimp for sharing!

So, SO much we don't know about the world around us...

I still stand by my comment that it's no wonder so many people have a disconnect with the natural world; even science is telling us how dangerous it is "out there"! Sheesh, no wonder I've never been able to spend more than a couple of years at a time in the environmental ed field; it can be such an uphill slog, so often a seemingly impossible one. Even more kudos to JZ for her boundless energy in continuing on!

I also still maintain that I am more likely to meet my end tumbling down the stairs after being tripped by one of my house cats than by bat bite, tick bite, coyote attack, or whatever. *lol*

Still dazed over the image of a vomitting vulture, Bill of the Birds and the Science Chimp together in a car. Oh, my, the smell alone... *gaugh*

I am more likely to meet my end tumbling down the stairs after being tripped by one of my house cats than by bat bite, tick bite, coyote attack, or whatever.

I imagine you're right; but I've watched a man die of rabies, in a movie they showed us in Hospital Corps school. It was drawn out and horrible. Like tetanus, where your entire body goes into cramp, the consequences are so awful that it's worth going way overboard to avoid them.

This was really informative and something to remember. A disease endemic in a bat may kill one of us. I'll remember your experience and take it seriously when I encounter a wild animal.

Julie, this is a really wonderful post. I've been following them all and have been endeared to the Big Brown bat, but was also concerned. As to evidence of rabies infection from urine or saliva, here's a link to an article from AAP Grand Rounds: http://aapgrandrounds.aappublications.org/cgi/content/extract/20/1/5
To see the whole thing you have to be a subscriber, but in the teaser of this retrospective study it does give info on rabies incidence from various causes. Of the 61 cases reported from 1950 to 2007, nine (16%) were touched by a bat without a bite, six (11%) had bats in their home, two (4%) found a bat in the room in which they slept. The rest (22, or 39%) were from bites. When I worked at AAP some years ago I recall seeing something on their website that gave detailed information about a number of cases in people whose only exposure had been from bats living in their attic or being in their bedroom. Of course, I can't find that now but was able to find this article. So, while I do not have any kind of expertise or much knowledge regarding rabies I think this points well to what Dr. Winship's letter concludes. That is, that there is little known about this disease in the bat population. Do be careful.

Julie, please be more careful. I understand that rabies can be caught by aerosol infection. Handling bats even if you think you are careful is not a good idea. The animal can be asymptomatic and still pass the virus on to you. Why would you have it in your house if the Health Dept. generally advises people to get vaccinated if they wake up and there is a loose bat in their house? You are putting your family at risk. Also, your argument about urine and feces is unsound because you are dealing with the live animal. And, you should run to the nearest doctor and get vaccinated. It may be the best $700 you ever spent! I enjoy your blog and I am concerned about you.

I've enjoyed reading this bat blog as it unfolds. I deal with bats everyday and some do carry rabies. Protection is foremost. What I don't understand is why you would test DeeDee. Having had the vaccine, if you get bit you would get two booster shots. Better to get the shot than to euthanize a likely healthy, education ambassador.

Corky
www.norcalbats.org

@ Corky:

I would have Dee Dee tested in the event that she bit me because

1. it's Ohio state law that any rabies vector species that bites a person gets tested--it's a requirement of getting the certification on my permit

2. I haven't had the vaccination yet (!) and it's going to take weeks to get my antibody titer where it should be

and 3. my life trumps the bat's.

Rest assured that I'm doing every darn thing I can to avoid having to test Dee Dee (see subsequent posts!)

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