Why are a higher percentage of Canadians dieing of SARS?

[Lancer]

mindseye, do you know if the original nasty strains are still around or did they mutate into less lethal strains?

[SpencerH]

Well its easy to speculate that differences in virulence are due to different strains but it's another thing to prove it. Last I heard, which was friday, there were 3 complete sequences. The canadian and CDC versions were essentially the same, but the chinese announced that they had a 'substantially different' sequence.

[Lancer]

It's the one that killed someone in asia, (Malaysia?) most of his family and quite a few health workers that bugs me. If that varient persisted, it would be truly terrible for humanity. One of the original cases outside China IIRC.

[SpencerH]

Originally posted by Lancer
It's the one that killed someone in asia, (Malaysia?) most of his family and quite a few health workers that bugs me. If that varient persisted, it would be truly terrible for humanity. One of the original cases outside China IIRC.

I think you're refering to the index case in Singapore. She had contact with virtually every other case in Singapore and it had a higher than normal mortality rate (at least early on).

[mindseye]

Well its easy to speculate that differences in virulence are due to different strains but it's another thing to prove it.

Today, on CCTV, they said that Taiwanese reserarchers had indeed proven this. The Hong Kong and Toronto strains are different.

[aaglo]

Canadians have very little or no correspondence with current south-east asian genes.

In the 13th century the plague affected some of the european genes so, that some europeans are immune to AIDS (not immune to HIV, but the disease will not turn in to AIDS on these individuals). This propably has something to do with SARS too.

This leads to the conclusion, that throughout times the SE-asians may have had some major disease outbreaks, thus changing the local gene pool, and giving them some resilience towards this kind of epidemics.

[SpencerH]

Originally posted by mindseye

Well its easy to speculate that differences in virulence are due to different strains but it's another thing to prove it.

Today, on CCTV, they said that Taiwanese reserarchers had indeed proven this. The Hong Kong and Toronto strains are different.

So far 10 isolates have been sequenced from nearly 7000 infections. There is no way anyone can 'prove' any epidemiology from such small numbers. What was expected, and what seems clear from the sequence analysis so far is that their are "mutation hot spots" that may relate to virulence.

The latest mortality figures show that the elderly are at great risk. Therefore it may be the age of exposed populations rather than real differences in viral virulence that explains the different mortality rates in the different countries.

[RedFred]

Originally posted by aaglo
Canadians have very little or no correspondence with current south-east asian genes.

Have you ever been to Toronto or Vancouver? I think you might be seriously underestimating the amount of Asian Canadians.

[Willem]

Originally posted by aaglo


This leads to the conclusion, that throughout times the SE-asians may have had some major disease outbreaks, thus changing the local gene pool, and giving them some resilience towards this kind of epidemics.

I don't think it leads to that conclusion at all. With any disease, there's always certain individuals that have a natural resistance. If not, mankind would have been pretty much wiped out during the Black Plaque. And these people will pass on their genes, hopefully, to future generations, so that they will have more resistance to these ailments. One generation's epidemic might wind up being future generation's inconveniences. I think SARS has good potential of falling into that category.

[Urban Ranger]

Originally posted by aaglo
In the 13th century the plague affected some of the european genes so, that some europeans are immune to AIDS (not immune to HIV, but the disease will not turn in to AIDS on these individuals). This propably has something to do with SARS too.

That's the Delta32 allele, which gives a person immunity to both the bubonic plague and to AIDS. So yes, it is theoretically possible that some individuals could carry genes that render them immune to SARS.

[Willem]

Originally posted by Urban Ranger


That's the Delta32 allele, which gives a person immunity to both the bubonic plague and to AIDS. So yes, it is theoretically possible that some individuals could carry genes that render them immune to SARS.

Why does that follow? SARS belongs to a totally different class of virus.

[Urban Ranger]

While SARS is a type of coronavirus, humans have also been exposed to the same family for millions of years.

[Lancer]

People who never get colds.

[Urban Ranger]

Maybe people who got measles shots? Perhaps the antibodies work well enough against the SARS virus? Who knows?

[alva]

Better be prepared