How do they know swine flu originated in Mexico...?

[dinny]

And not previously, somewhere else in the world if they only started testing for it fairly recently...?

Look on You-tube, lots of interesting theories there. Careful you might scare yourself.

oooh, like what Ripeberry?

Actually the virus has been around for years I believe in pigs (hence swine flu) but it jumped species and hospitalised some folks in a small town in Mexico near a big pig facility (I mean for lots of pigs, not one big pig though that would explain how so many sausages could come from one place )

It then developed human to human transmission.

The interesting thing is that the ingredients in terms of genetics for H1N1 are not novel. We're just lucky it's not avian flu which is human to human transmitted (yet).

I thought it originated somewhere in the US.

What I mean is the combination of genetic elements is interesting. Could have happened at any point and yes of course there are viruses 'in the wild' which are not identified or analysed. DS had one three months ago - docs couldn't identify it in any way, because actually we only look at the immune response generally and not the bug (ie we look at symptoms and rarely identify the cause unless it's well known and there is a known test for it).

pmsl@ one big pig.
I knew it would all go pear-shaped when they started breeding these giant 40 foot high pigs.

dh and I had SF the other week and it wasn't as bad as the flu, which was unidentified that we both had last year, which left me coughing for two months and struggling to breathe/begging the Dr for them to do something (they kindly said take some more time of work and more echinecha ) its just a virus

wmmc, why is avian flu so much more dangerous?

we all had such bad flu at Christmas last year, was wondering if there was any chance it could have been swine flu!

Lol at wmmc's Giant Pig.

My uncle lives next door to a piggy farm in Somerset...ho hum....

Avian flu is more dangerous because it causes respiratory paralysis - and we don't have enough ventilators if wide swathes of the population can't breathe.

Seasonal flu is really bad. I had it once and I did think I was dying for at least a week. It wiped me out for months afterwards. Flu is no joking matter.

Poultry workers are going to be up high on the list of who gets jabbed first for swine flu because of the danger of someone with swine flu infecting a chicken and it mutating into an avian/swine mix (chigen) to create a more deadly virus.

Chigen is not a real word, I made it up btw - I just can't think of what you'd call it.

Chigen.

Big Pig.

WMMC's Dictionary of SF Terms

Good, re vaccinating poultry workers.

Chicklit - the books you read while in bed suffering from bird flu.

Am sure there's something to be done with 'ham and eggs' but am too sleepy to do it....

Actually I do have a question about virii that I've not been able to answer. It's this: vaccines are created by injecting purified parts of a virus into an egg and incubating it. (I assume people realise this and that's why if you are allergic to eggs you might have probs with vax jabs). Now, we are trying (very hard) to avoid the possibility of allowing the H1N1 virus to get into the type of animals known as 'birds'. So how does it become sensible that we are sticking it into eggs. How do we know this isn't then going to carry bits of bird DNA and H1N1 onto a vaccine researcher and create a whole new bundle of RNA which is pretty lethal?

are you a scientist,

God, scary stuff - is the respiratory paralysis likely to happen in otherwise healthy people?

also, will it be a lot worse getting it in the winter than now?

and what might happen if it mutates?

bloody fecking factory farming

and totally agree with the egg comment - what is RNA?

WMMC: the influenza virus RNA gene segments of wild-type swine H1N1v are first added to a well-tried vaccine strain called PR8 (which is known to grow well in eggs). This PR8 'vehicle' is just a way of getting rapid adaptation to egg culture and has a good safety record. It's the same methodology by which the seasonal H1N1 and H3N2 vaccine strains have been made for years.

This modified H1N1v/PR8 seed vaccine is then grown in sterile eggs to a higher titre in the allantoic fluid, which is removed and the whole virus purified. The vaccine is made by inactivating the virus and further treating it; depending on the manufacturer.

Having bird DNA around in the process is not a problem because it isn't a dangerous substance. If there were avian H5N1 virus around, then that would be different; however the eggs are sterile and the virus reassortment would not occur.

BTW swine flu is not causing "respiratory paralysis". This is something quite different clinically and seen with diseases that affect the respiratory nerves eg polio. The clinical picture of severe swine flu in critical care is of patients very difficult to get properly oxygenated because of viral pneumonia and excess fluid in the lungs. Even on 100% oxygen they are just hanging on; hence the need for ECMO which is a v new technology and as we've seen not many units around.

Musukebba, what is ECMO?

There is more evidence emerging that swine flu didn't in fact originate in Mexico - that was just where the first cases made the headlines. There would have been a clearer picture of origins except that the WHO seem to have pandered wholesale to the pig-farming industry and muddied the waters in the very beginning, so not as much data was collected or made available as might have been. It was easier to say 'Mexican flu' than to say 'swine flu that might actually have come from not very far away, folks' iyswim.

(Am not scientist but dh is.)

Sorry, I said WHO, but I meant to say 'and CDC'.

Times today says the first Mexican "victim" was not the boy who lived on a pig farm but a baby who had been nowhere near a pig.

dinny: ECMO is extra corporeal membrane oxygenation ('extracorporeal' meaning "outside the body"). Basically blood is diverted away from the lungs and a machine performs the function of getting oxygen into the blood.

Re swine flu origins: there is an excellent London Underground-style map of how the current human swine flu evolved in a paper from Nature here. One important conclusion is that the progenitor virus was circulating in pigs for about ten years before acquiring a couple of avian genes and being able to readily infect humans.

Musukebba - ah that makes more sense thank you.

BTW I wasn't saying swine flu was causing respiratory paralysis - but Avian flu could. It's not paralysis though - I used the wrong word and can't remember what the word is - it's what my MiL had though!

I thought meningitis and pneumonia were the big complication risks of flu because it overwhelms the immune system and puts you at risk of things you'd normally bat off.

I thought that there was a swine flu outbreak in the USA in the 70's?