SARS looks like a potential pandemic.

[O Great One]

It looks like SARS may become a world-wide pandemic.
How do these diseases just pop up?
Ordinary viruses must undergo mutations which turn them deadly.
Is this correct?

 

[Another God]

Yep. Virus' are just as prone to mutation as everything else is.

 

[Monique]

The virus might have acquired its characteristics by exchanging elements w/ another virus, causing a new more virulent form. It might also already have been present in animals and it just changed host.

A problem w/ virusses that it is not so easy to treat them, luckily it doesn't seem to very deadly, many people have survived the illness.. let's hope they are able to develop a vaccine.

 

[Phobos]

Originally posted by Monique
let's hope they are able to develop a vaccine.

Or even contain it. Seems like the world is attacking it at the beginning stages (e.g., quarentines). Hopefully that will stop a pandemic. Better to see it coming early than to be behind the curve on something like this.

 

[FZ+]

Then again, it's early days yet. The virus has been more or less just identified, and I would not say the current case is sufficient in scale to be truly catastrophic. But with modern transport, who knows... For now, quarantine and a big international research effort seems critical.

Monique: It is thought now that the virus, of the measels family, did in fact come from animals to humans. This can be a problem...

 

[Monique]

HIV-virus came from animals too..

 

[damgo]

Good news... CDC says they're close to chasing down the SARS virus, and Hong Kong doctors think they've found an anti-viral agent (Ribavirin) with good effectiveness against it.

http://www.cnn.com/2003/HEALTH/04/01/sars.cdc/
http://www.cnn.com/2003/HEALTH/04/01/hk.sars/index.html

 

[Deslaar]

Think global, act local. Stay away from airports and people who've been to airports.

 

[LURCH]

Originally posted by Monique
HIV-virus came from animals too..

Has that been confirmed? I'd allways heard it was suspected, but I never heard it was proven.

 

[Deslaar]

Originally posted by LURCH
Has that been confirmed? I'd allways heard it was suspected, but I never heard it was proven.

It seems reasonable. I wouldn't think that it would be so difficult to identify a new strain of an existing human disease.

 

[FZ+]

Yes, I think it's pretty much accepted that HIV came from SIV. (No, not that Siv, I mean Simian Immunodeficiency Virus, or something like that... )

 

[KLscilevothma]

they've found an anti-viral agent (Ribavirin) with good effectiveness against it.

I've heard that this drug works better in women and children then men and older persons. Those patients who smoke are more more difficult to recover from the atypical pneumonia. For some cases in which patients show no good responds to the drug, doctors use antibodies from recovered person to treat those who are sick, this works quite well too.

It might also already have been present in animals and it just changed host.

Just like the bird flu, H5N1, attacked people in Hong Kong few years ago.

I watched a tv program yesterday in which a doctor in Canada (if I remember correctly) said that he got a patient suffered from SARS, who's situation was worsening, then he suddenly became better and better without much help from drugs !

 

[Loren Booda]

The origin of many disease vectors begins in China where there is a dense population, many people living with livestock and poultry, poor control of epidemics (as the Chinese government admitted this week) and a large movement of goods and people to outside the region.

 

[mich]

Hi Monique:
How does an anti viral agent work to get rid of the virus?

Thank you for your time

mich

Originally posted by Monique
HIV-virus came from animals too..

 

[Jikx]

Originally posted by Loren Booda
The origin of many disease vectors begins in China where there is a dense population, many people living with livestock and poultry, poor control of epidemics (as the Chinese government admitted this week) and a large movement of goods and people to outside the region.

In reality, it will be pretty hard to contain it in a city that packs millions in a tiny area. But still, China should have told WHO so to limit its spread to other countires.

 

[Monique]

Originally posted by mich
Hi Monique:
How does an anti viral agent work to get rid of the virus?

Thank you for your time

mich

Hi Mich, well, there are several ways. The main problem with virusses is that they are inside our own body cells so difficult to recognize or to target. The main thing you would want to do is target one of the virus-specific pathways. In the case of SARS, we are dealing with a virus that is made up of RNA (rather than DNA) as a genetic material. For an RNA virus to work, it first needs to covert itself to DNA, this is good step to target since it doesn't occur much in our own body cells.

What I understand is that Ribavirin works by creating such extreme mutation rates in viruses that it drives them into "genetic meltdown". This is done by targeting the RNA-dependent RNA polymerase enzyme. Using poliovirus, a team observed a 99.3% loss in viral genome infectivity after a single round of ribavirin mutagenesis sufficient to cause a 9.7-fold increase in mutation frequency. Interestingly, this is the first time it has been demonstrated as a mechanism for a working drug.

For more detailed information about ribavirin: quote..
At present there are 4 proposed mechanisms of action of ribavirin. They can be divided into 2 groups. The first group consists of 2 possible indirect mechanisms: (1) enhancement of host T-cell-mediated immunity against viral infection through switching the T-cell phenotype from type 2 to type 1 and (2) inhibition of the host enzyme inosine monophosphate dehydrogenase (IMPDH). The second group consists of 2 other hypotheses: (1) direct inhibition of HCV, including NS5B-encoded RNA-dependent RNA polymerase (RdRp) and (2) as an RNA mutagen that drives a rapidly mutating RNA virus over the threshold to "error catastrophe." Author: Johnson Lau in Hepatology (may 2002, Volume 35, Number 5)

 

[Saint]

can SARS eradicate human beings ?

 

[KLscilevothma]

can SARS eradicate human beings ?

no because people can get well from sars. Only those who have weak immune system, old or have other chronic diseases are more vulnerable to sars.

 

[Monique]

I heard the number that 1 in 25 dies, I am not sure how correct that is though.

 

[FZ+]

But mutations can always occur and we could be seeing the tip of the iceberg here...

 

[Bubonic Plague]

What I understand is that Ribavirin works by creating such extreme mutation rates in viruses that it drives them into "genetic meltdown".

How does extreme mutation rates kill the viruses? Won't the extreme mutation rates cause the virus to "spawn" numerous new viruses, aggravating the situation rather then saving it?

 

[iansmith]

Originally posted by Bubonic Plague
How does extreme mutation rates kill the viruses? Won't the extreme mutation rates cause the virus to "spawn" numerous new viruses, aggravating the situation rather then saving it?

Most mutation are harmfull. The probablity to create a more powerfull mutant by mutation is very low (1 in a billion). The mutation also have to occurs in a gene to can accept a higher mutation rate. Some gene had very little mutation during evolution. The mutation rate is probably greater than 10^-3

 

[russ_watters]

Originally posted by FZ+
But mutations can always occur and we could be seeing the tip of the iceberg here...

We certainly are only seeing the tip of the iceberg. New viruses are popping up all the time. COULD we get a new plague? Certainly. I wouldn't lose any sleep over it though.

The people (prodded by the media) are reacting to a baseless fear of a pandemic with this one. 90 deaths so far? 4% fatality rate? This virus isn't even statistically relevant. Wake me up when it starts killing 40,000 a year (like the flu does in N America).