SARS Much More Deadly Than First Estimated

New Scientist ^ | 4-25-2003 | Debora MacKenzie

[blam]

SARS much more deadly than first estimated

13:43 25 April 03

NewScientist.com news service

Analysis of the latest statistics on the global SARS epidemic reveals that at least 10 per cent of people who contract the new virus will die of the disease.

The low death rates of about four per cent cited until now by the World Health Organization and others are the result of a statistical difficulty, well known to epidemiologists, that hampers the early analysis of new disease outbreaks. This difficulty is the reason for the apparent rise in death rate - not a change in the SARS virus.

A fatality rate of over 10 per cent puts SARS on a par with some other RNA viruses. Yellow fever and Japanese encephalitis, spread by tropical mosquitoes, between them kill more than 10,000 people a year, even though both have vaccines. Lassa fever kills about 70,000 a year in West Africa, but people mainly catch it from a local mouse.

Because these infections need animal vectors that only exist regionally, none has ever gone global. But the SARS vector - humans - is everywhere.

Draconian measures

The emergence of the true deadliness of SARS comes as further draconian measures are implemented by health authorities around the world.

The latest is the quarantining of 4000 people and the complete isolation of two hospitals in Beijing. China, where the virus emerged, has about half the world's known SARS cases, which have now risen to total 274 deaths and over 4800 infections.

The standard figure used to gauge the deadliness of any disease is the "case fatality rate" (CFR). This is the number of deaths divided by the number of cases of the disease.

Early in the SARS epidemic, the CFR was about four per cent. But the CFR calculated from statistics released on Thursday and Friday for Hong Kong, Canada and Singapore are now 7.6, 10.7 and 9.9 per cent respectively. These three places are the worst hit after the Chinese mainland.

The global CFR has risen steadily since the start of the epidemic but this is to be expected, say epidemiologists contacted by New Scientist. Early in an epidemic, a significant proportion of the total number of cases have neither recovered nor died. Some will eventually die and so move from the denominator to the numerator of the CFR, raising its value. The CFR moves towards the true value as time passes, unless the number of new cases explodes.

Better estimate

With many cases still unresolved, a better current estimate of the deadliness of SARS may be the number of deaths as a proportion of resolved cases. Those numbers for Hong Kong, Canada and Singapore are 15.8, 18.3 and 13.7 per cent. But these too could be misleading if, for example, it takes longer to recover from a disease than to die from it.

In China, this death rate is only 8.8 per cent. But statistics there are widely mistrusted, after Chinese authorities withheld nearly all information until recently. The Chinese statistics may also include cases of pneumonia due to bacterial infections, a widespread problem there, and which are cured with antibiotics.

One way to resolve the uncertainty over the death rate, say epidemiologists, would be to take a "cohort" of cases that start at the same time, and follow them until all have resolved. Several groups, including Roy Anderson and colleagues at Imperial College in London, plan to publish detailed epidemiological analyses shortly.

Uncertainty may dog the exact calculation, but it now seems clear that in the absence of a cure or a vaccine, SARS could eventually kill millions. The best hope is a vaccine. At a high-level meeting last week in Washington DC, every major vaccine company reported that it had begun a research programme.

Debora MacKenzie

[Judith Anne]

Good posts. Thanks.

[Judith Anne]

I don't think that SARS is related to HIV. I do think that HIV+ people are more at risk from SARS.

[E. Pluribus Unum]

Now tell me, is this hysteria? Or your ignorance?

Neither. It's your pompousity.

[E. Pluribus Unum]

In your analysis in reply #49. I beleive you based your conclusion that SARS is no big deal your analysis using the number of deaths so far this year as a constant for every year.

So what is your estimate of how many people die every year? 50,000,000 is probably low. You come up with a number, if you can.

[E. Pluribus Unum]

You do seem a bit riled up about this. Is it that you are so excited because this SARS thing is now playing into your paranoid fear of the government's anti-terrorism efforts and you want us to all latch onto that paranoia too?

FEMA is chomping at the bit for the opportunity to declare marshall law. They are watching this with keen interest.

[GeekDejure]

. Caution !!! Do NOT sniff your monitor while reading this article !!!

.

[FreepForever]

Re: SARS and HIV/AIDS read this

http://www.atimes.com/atimes/China/ED24Ad03.html

Excerpt:

If just one person infected with SARS is on any of the countless trains now leaving Beijing, these trains could significantly increase the speed of the spread of SARS throughout China's interior. The tragic irony of this exodus is that everyone leaving Beijing hopes to avoid getting SARS there, but they will in all likelihood contract and spread it throughout the country, to strangers, friends and family. Which brings us back to HIV/AIDS.

Beijing has admitted to covering up SARS statistics in order to preserve the image of normalcy. This seriously hurts the CCP's credibility.... It is obvious that the highest levels of government in China are not averse to lying to its constituency or the world in order to maintain an image as a safe, stable environment for foreign direct investment.

Assuming that SARS makes its way to every populated area of China, it is quite plausible that China's SARS deaths could experience a ferocious increase. SARS is an atypical pneumonia caused by a coronavirus. AIDS sufferers are particularly susceptible to pneumonias. Indeed, the most common serious infection among AIDS patients in the United States is a type of pneumonia called Pneumocystis carinii pneumonia (PCP), which is typically fatal if not identified and treated quickly. Identification requires a laboratory test of fluid or tissue from a patient's lungs. Unfortunately, most of the people with AIDS, in Henan in particular, do not have access to laboratories, nor the money to pay for tests and treatment....Unfortunately, because of Beijing's foolish handling of HIV, and now SARS, many Chinese are going to die. The question is how many.

It seems apparent from the government's reaction to either epidemic that the economy is its top priority. Therefore it is reasonable to conclude that Beijing will do little to protect China's impoverished hinterland. This makes it quite plausible that SARS could kill tens or hundreds of thousands of people in China alone.

[FreepForever]

Neither. It's your pompousity.

Despite all those draconian measures you called pompous, Hong Kong is barely able to keep the new cases per day from an all time high of 80 to 30.

[blam]

"FEMA is chomping at the bit for the opportunity to declare marshall law. "

Marshall died. You're probably thinking about martial law. (Martial law is law that is enforced by the military.)

[FITZ]

SARS is an atypical pneumonia caused by a coronavirus.

If it's a coronavirus that can infect (or even came from birds), quarantining only people isn't going to stop the spread of it ---and migratory birds often are what's behind the spread of colds and flus. We can't quarantine them.

[FreepForever]

Hey, hey, hey, cool down.

I've check with the vets. They say that coronavirus existed in feline, swine, etc. all along. They are mild and not that contagious. On cats, it cause a common cold and on pigs, it cause enteritis. And, they have treatment as well as vaccines for that.

The coronavirus we are facing now is a mutated virus from that family. If the virus can jump from animals to human, it would happen years ago. So, don't go and kill your cat.

Stay safe.

[handk]

SARS Scam

[FITZ]

I'm in no panic ---I'm not thinking about dying or anything ---but I don't believe quarantining humans is necessarily the answer ---it might be a futile waste of time. Sometimes a virus that isn't too deadly in it's natural host --like a bird ---becomes deadly if it jumps species. I'm not even going to kill my birds much less my cat.

[aristeides]

WHO accepts Sars 'more deadly' claim .

[Judith Anne]

That's a quiet little article with profound information in it.

Wasn't per loin well ahead of the game, in this regard?

[FreepForever]

The vets' logic is: if those coronavirus existed in cats are that deadly and contagious as the strain that we are witnessing now, the virus would have wiped out all cats years ago. So, don't worry, my friend. I'm animal lover too.

However, you do have a point. The Hong Kong Health Dept found out that mouses and cockroaches in Amoy Garden (HK's SARS epic center) did contain that virus. May be they just got contaminated from human waste/discharge but they themselves are not the host.

[blam]

"Wasn't per loin well ahead of the game, in this regard?"

Yup. Looks like per loin has been ahead of the curve all along.

[aristeides]

With a really deadly disease, only members of the victim species that are immune to it survive. That may have happened to cats long ago. It may be in the process of happening to humans now.

[Judith Anne]

Impressive. Right here on FR.