Posted on 04/25/2003 3:08:17 PM PDT by 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
civilization, of course..
I expect the higher numbers to be closer to the truth. 10% or higher.
This whole SARS thing is being blown WAY out of proportion.
There are 6,000,000,000+ human beings on the planet.
The world's record for longevity is ~120 years.
6,000,000,000 / 120 = 50,000,000 people dying every year, at least.
So far there have been ~500 SARS deaths.
500 / 50,000,000 = 0.001% of the deaths expected this year are due to SARS.
Give me a break.
That could be true. How many respirators per population would the average hospital have ? Will we have riots when the hospitals start turning away patients because all the beds are full ?
http://www.dividingline.com/private/Terr/Terrorism_FewHospitalsReady.shtml
Hospitals across the country are scrambling to prepare for terrorist attacks, anticipating situations that seemed like science fiction nightmares before Sept. 11. But public health experts and hospital industry officials say that many hospitals are far from ready for a surge of patients in the event of a major attack.
Fifteen years of cost-cutting under managed care has shrunk emergency room capacity, sharply cut inventories of drugs and equipment and eliminated thousands of hospital beds. A nationwide shortage of nurses and pharmacists would make it even harder for communities to respond quickly to a major disaster....
~~snip~~
"Hospitals are working at a bare minimum to meet the needs of patients," said Dr. Mohammad N. Akhter, executive director of the American Public Health Association. "If there was a bioterrorist attack, the number of patients would overwhelm our system." "If they use a contagious agent like smallpox, we will not have isolation facilities to quarantine people," he said. "If there's a major attack that would require more than 500 beds, no community has that number of extra beds available."
Yes I think you're correct, EH.
As summer approaches and the SARS epidemic declines, there will be an understandable urge to celebrate. But history teaches us that the devastating 1918 influenza epidemic began with a modest "herald wave" in spring that faded away during the summer, only to explode and wreak global devastation the following fall and winter. It is possible that SARS, now seeded around the globe, could follow a similar pattern and fade away this summer, only to erupt again next winter.
The coming summer lull in SARS affords an extraordinary opportunity. If we can detect, diagnose and effectively isolate every contagious case during the period when the infection rate is at its lowest, it is possible that we can truly eradicate SARS, not just for the short term, but permanently.
This is from Dr. Burke at Johns Hopkins, the article is at the Wall Street Journal, a subscribers only page unfortunately. The link is in post 10, by Blue_Ridge_Mtn_Geek.
The SARS cases we are seeing this spring are called the "herald wave." You may know this already, I just couldn't recall the terminology. If I write it down, I'm more likely to remember it...
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