h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I remember some kind of flies ("Rachendassel" in German, the dictionary calls them 'sheep nostril fly') which spray their eggs into the mouthes of /cows/, and their mites grow within the throat. Perhaps these transmit the disease? I don't know.

Hi Bossel

That fly sounds very unpleasant. Poor sheep and cows! I don't know whether those "Rachendassel" could transmit prions. The flies and larvae I mentioned earlier in the thread were tested in separate experiments. The flies didn't pass the prions on to the larvae. The scientists didn't say the flies and larvae were infected in the sense of, so to speak, suffering from the disease. They were merely contaminated - carrying the prions they'd ingested. They didn't mention anything about flies passing prions on in their eggs. That isn't to say it isn't possible. I just haven't read anything to indicate that it might be. So much is still unknown about the diseases. It's interesting that something so horrible can be so interesting, don't you think?

Sal

I just read a facinating publication by the Center for Disease Control in the US that stated that there is a particular amino acid sequence that can either be a methionine, a valine or another choice which eludes me right now. These are distributed in the population with various frequencies. People in the UK who becme infected from BSE were all methionine bearers while the other amino acids seem to confer some protection to infection. A worse case scenario is that theother variants are just longer times of incubations which would mean the brunt of the infection is still to come. In either case I thought it was an interesting tid bit I thought I'd share.

yes, somewhere like cannibalism...
But, as I said, I don't know, and those flies /are/ nasty. Apart from breathing difficulties, cows don't get their calm to rehash and all that. My poor electrically-educated brain just fantasizes about cows swallowing some of the mites, and then the herbivores' digestion comes into play again -- some weird sequence of events, but diseases aren't always logical, are they.

Ariel, the amino acid sequence protection you describe sounds similar to the species barrier story. The PrP gene that all the species so far tested carry varies from species to species. The cellular PrP might vary between 2 different species by, say, a couple of amino acids or 30 amino acids. The more similar the normal cellular PrP of 2 species, the more likely that one species can get a prion disease carried by the other. It's possible that the people who got vCJD had a slightly different gene for cellular PrP than most of the rest of the beef eating public. Perhaps some had one or more point mutations in their PrP gene - just enough to make their PrP sufficiently similar to the BSE prion, for it to do its work. Thanks for sharing that news. It's very intriguing, isn't it?

Bossel, when you say the 'cows don't get their calm to rehash' do you mean they can't chew the cud (return the partly processed grass/hay to their mouth for another chew, the way cows normally do)? Next time I see the local farmer, I'll ask him if he's ever heard of those nasty flies.

I get the impression you're brewing up one of those films we get on the Sci-Fi channel. Let me know when it's out on video (I never go to the cinema any more - too much coke and popcorn flying around).

Sal

"return the partly processed grass/hay to their mouth for another chew", yes, that's what I wanted to say, and the words I chose actually came from the dictionary And no, I've never seen this topic covered anywhere in movies or on TV. I grew up in a rural area, that's why I know about those flies.


BTW, there are lots more ugly creatures around, such as the "Kriebelmücke" (simulium sp., black fly [URL removed by moderator]a type of gnat which, apart from the sheer nuisance, transmits different kinds of parasites (such as the worm responsible for onchozerkiasis in tropical regions) and diseases. Simulium sp. killed 16000 cattle in 1923 in romania.
Simulum columbaschensis killed 12000 cattle in yugoslavia in 1934.

I think step one in solving the spreed, is to stop ranchers from grinding up sick animals and feeding them to the healthy ones. Just my opinion. (eats and watches Jurasic Park)

Bossel, thanks for the link. Interesting article. The description 'black fly' covers lots of different species of fly. There was a very amusing cartoon and song about the little black flies of 'North Ontario-io' in Canada. They also like to bite and suck blood. Their feeding habits, as described in that article, sound similar to the mosquitoes that spread malaria where the female requires a blood meal and the male drinks nectar. The female black fly feeding technique also sounds similar to the method used by ticks. They cut a hole in the flesh of their victim, inject anticoagulants and feed on the blood that pools in the wound. Ticks carry a range of diseases too. Lyme disease is probably the best known.

Yesterday I asked someone from a local farming family if they knew of a fly that sprays its eggs into the mouths of cattle. He said he'd never heard of such an insect. He was aware of the gadfly which sucks the blood of cattle and, he said, it ruins the hide by laying its eggs in the skin of cattle. He was also under the impression that scrapie in sheep was caused by worms that burrow into the sheeps' brains. Hmmm. Maybe the damage done by the worms he mentioned, causes similar symptoms to scrapie. Maybe he doesn't get much time to listen to the News.

George, if ranchers are "grinding up sick animals and feeding them to the healthy ones", I agree with you - they should stop it. But your reference to ranchers makes me think you're probably in America. If you live in the US, according your Department of Agriculture, no BSE has been detected in your country. If you don't trust your government to tell you the truth though, perhaps you'd better stick with the popcorn

Sal

If you want, Salamander, I could give you all the words to that 'North Ontario-io' song. It's one of my favorite shorts and was written by Wade Hemsworth in 1949 whail he was working on building a dam on the Abitibi River in Ontario, Canada.

Yes please George. It's a few years since I've heard it. I've tried to remember the words but it's no use - I can't remember where in my brain I filed them. That Wade Hemsworth must've really suffered for his art.

Thanks!
Sal

Here Sal, I hope it works without the music. ENJOY!!

"Twas earliy in the spring when I decided to go-o,
For to work up in the woods in North Ontario,
And the unimployment off said they'd send me through,
To the little Abitibi with the survey crew,

And the black-fly, the little black-fly,
Always the black flies no matter where you go,
I'll die with the black-fly picking my bones,
In North Ontar-io-io, in North Ontar-io.

The man Black Toby was the captain of the crew,
And he said "I'm gonna tell you boys what we're gonna do,
They want to build a power-damn and we must find a way,
For to make the little Ab flow around the other way."

And the black-fly, the little black-fly,
Always the black flies no matter where you go,
I'll die with the black-fly picking my bones,
In North Ontar-io-io, in North Ontar-io.

So we surveyed to the east, surveyed to the west,
And we couldn't make our minds up how to do it best,
Little Ab, little Ab, what shall I do?
For I'm all but going crazy with the survey crew,

And the black-fly, the little black-fly,
Always the black flies no matter where you go,
I'll die with the black-fly picking my bones,
In North Ontar-io-io, in North Ontar-io.

'twas black-fly, black-fly everywhere,
A-crawlin' in your wiskers, a-crawling in your hair,
Swimmin' in the soup, swimmin' in the tea,
The Devil take the black fly and let me be,

But the black-fly, the little black-fly,
Always the black flies no matter where you go,
I'll die with the black-fly picking my bones,
In North Ontar-io-io, in North Ontar-io.

Black Toby felt a swearin' and the work went slow,
And the state of our moral was a gettin' pretty low,
The flies swarmed heavy, it was hard to catch a breath,
As you staggered up and down the trail a-talkin' to yourself,

And the black-fly, the little black-fly,
Always the black flies no matter where you go,
I'll die with the black-fly picking my bones,
In North Ontar-io-io, in North Ontar-io.

Well now, the bull cook's name was Blind River Joe,
If it hadn't benn for him we'd a-never pulled through,
'cause he bound up his bruises and he kidded us for fun,
And he lathered us in bacon grease and balsum gum,

For the black-fly, the little black-fly,
Always the black flies no matter where you go,
I'll die with the black-fly picking my bones,
In North Ontar-io-io, in North Ontar-io.

And at last the job was over, Black Toby said we're through,
With the little Abitibi and the survey crew,
'twas a wonderful experience and this I know,
I'll never go again to North Ontar-io,

With the black-fly, the little black-fly,
(sing slowly)Always the black flies no matter where you go,
I'll die with the black-fly picking my bones,
In North Ontar-io-io, in North Ontar-io."

That's great George! I've printed it out and when I've finished struggling to get it to fit in with the tune, I'll file it in a ring binder where I'll be able to find it again. It'll be so much easier than trying to find it in a brain where some of the draws aren't labelled and don't even have handles in some case.

Thanks ever so much!

Sal

I'm supprised no one has called me on continuity yet. In the first conversation forum I was in, I tried to become part of an adventure in the woods behind the AROMA CAFE, but I got called on continuity for everything I typed, then I was thrown out! How refreshing it is to be in a forum where random ideas can flow whial maintaining the central issue......prunes,right? Or was it prions? (just kidding)

By the way Sal, how did you know I was an American?

It was only a small digression. The flies are a valid part of the subject because they were found to be a possible vector. The song was very useful for umm, well, showing how voracious those flies can be. When you consider that flies tend to regurgitate when they feed, you'd want to be sure their last meal didn't contain prions if you're going to provide their next meal. (also just kidding ... I hope )

I didn't know you were American. I was just guessing. You mentioned ranchers. We don't have ranches in Britain. We have farms. We normally associate ranches with North America, South America and Australia.

Sal

Ahhh... A friend of mine thought you would pick up on the dialect. I can do a rather good Brittish-English accent, or at least I think so. Most people say I sound more Scott than Britt. Now about these flies who, for euphamism's sake, produce a prion-infested technicolour yawn, don't flies lay their eggs on carion specifically? And dosen't fly-distribution lend to the risk of an infected fly stowing away in an innocent turist's luggage and escaping fumigation? I'm scared Someone hold me...

Err, sorry, can't hold you, but perhaps have to embarrass you even more

With a little help from the Munich zoo (Hellabrunn, sure worth an entry of its own!), here are some more details about the 'Rachendassel' or also 'Rachenbremse'. If you've got weak intestines you may perhaps not want to read on...

Its family name is 'Oestridae'. Once knowing that, any search engine just fires away with links. 'Cephenemyinae' could be their subfamily, I'm not sure on that. Their mites are parasites to cattle, wandering around below the hide ('Hypoderminae', 'Hypoderma bovis') or in places like the breathing apparatus.

Hypoderminae then reach the spinal cord (sic, perhaps a link to BSE?) where they pupate (sp?) into a second type of larvae which wanders back under the skin and converts into state 3. From there they break free, fall to the ground and pupate again. The adults are short lived, they only copulate and disperse their eggs, either laying them down on the skin (to drill a hole there, or to be licked up) or, like I said, spraying them into nostrils of cattle.

There's a link to humans too: humans can serve as a temporary host, where mites won't grow but stir inflammations around eye and nose.

Umm, I won't go on with that.

* feels an itching somewhere down the neck *

Some links:
[URL removed by moderator] (Overview of all those nasty creatures)
[URL removed by moderator]

Now, you said that the infection could not spread to humans because of physiological differences, yet it can travel from Cattle to Sheep, could a rat that ate an infected animal pass the prions around after bitting healthy ones?

Just managed to get through long enough to read your messages George and Bossel. H2g2 seems to have been incommunicado this evening. I'll do a proper reply tomorrow (if things are back to normal). In the meantime:

George (posting 56), Scotland is part of Britain. My Scottish relatives would give me a tartan tongue-lashing for implying otherwise. As is the case in the US, we have a lot of different accents here - some of which I even understand. As for flies laying their eggs on carrion - different species of fly have different feeding and egg laying habits. Have a look and those links Bossel has given us.

(posting 58) I think a little bit of confusion has arisen here George. There are quite a few prion diseases. Humans are susceptible to some of them and not others. (It might be wise to insert the words "probably" and "yet" in that last sentence, given the current levels of knowledge and ignorance on the subject). Tell me which on my posts contains that ambiguous bit of info and I'll clarify.

Bossel, thanks for all these links. I've had a quick look at them (they look absolutely revolting - but very interesting) and I'll have a more careful read through later today (it's just gone 2.20am and my eyes refuse to stay open). I'll tell you how I found the material when I've err, recovered. By the way, I think you've got a little language hiccough with flies and "their mites". I think you probably mean larvae or maggots. Mites are a different species to flies. They're more closely related to spiders.

Speak to you later.
Sal

Ah ha, I've had a look back and found your original post George (posting 22) and my answer (posting 23). This is the relevant bit of the answer I gave back there:

"I can't answer your question about prions being transmitted by an infected animal's bite because I haven't come across any information about that. I guess most of the animals with a prion infection have been sheep and cows that don't tend to go around biting people. Anyway, there's a species barrier and most prion diseases can't cross it. The BSE prion seems to be the most adventurous one, that's game to infect lots of different species."

That still stands. I could only speculate about whether it might be possible for a rat to pass on a prion infection with a bite. I have no idea. If it were possible, I would guess that the rat would have to eat the infective bits of an animal carrying a prion disease to which the rat was susceptible, the prions would need to aggregate in the area of its mouth (they do tend to collect in tonsils) and it would have to give a similarly susceptible animal a prion infected bite. In any case, until the scientists do the work and let us know the answer one way or the other, your guess is as good as mine.

I'm off to read those links now.

Sal