Posted on 06/18/2003 7:14:24 PM PDT by Prince Charles
SARS Epidemic May Reemerge, CDC Director Warns
Wed June 18, 2003 03:04 PM ET
CHICAGO (Reuters) - Like deadly flu epidemics of the past, SARS may reemerge later this year as a global health threat, the director of the U.S. Centers for Disease Control and Prevention said on Wednesday.
Dr. Julie Gerberding pointed out that infectious diseases like SARS and monkeypox are spread around the world by travelers or by trade in exotic animals.
"This is the new normal: emerging infectious diseases ... that create immediate global concerns because of the movement of people and animals," Gerberding said in a speech to the American Medical Association's annual meeting.
Gerberding compared SARS to flu epidemics early in the last century that appeared to subside, only to erupt again with the change of seasons and kill millions.
"The risk is not over as any moment another patient could emerge," she said.
The World Health Organization said this week the worst was over in the battle against SARS and lifted a travel warning for Taiwan, leaving Beijing as the only place with an advisory in force.
But the United Nations agency said health authorities must stay alert for fresh outbreaks of the disease that killed almost 800 people and infected about 8,500 since it emerged late last year in southern China.
Gerberding said the number of cases was "definitely dwindling" but the Northern Hemisphere's fall and winter could witness another outbreak.
"Our next priority is to develop a rapid diagnostic test," she said. "We now know there are milder forms of the illness where people may not have symptoms. What we don't know is if these people can transmit the virus."
The monkeypox outbreak in the U.S. Midwest this spring caught health authorities by surprise, she said, and showed how the movement of people and animals around the globe posed health risks. There have been roughly 80 non-fatal human cases so far traced to pet prairie dogs, with the infection traced to a Gambian rat imported from Africa.
She said no new human cases of the deadly West Nile virus appeared in the United States so far this spring, though the CDC was tracking bird and mosquito virus carriers and expected the deadly illness to reappear this summer. Last year, there were more than 4,000 human cases and 284 deaths.
The WHO conference on SARS in Malaysia has just ended with warnings to remain vigilant because SARS could re-emerge and the animal reservoir is not well defined. The SARS epidemic is about to enter the 2nd 100 days since WHO issued its alert, but it is not clear that officials are paying attention.
SARS is not going to re-emerge from the wilds of Guangdong Province from some exotic animal. SARS is right here in River City, complete with a strong set of deletion and point mutations.
SARS emergence from wild animals in Guangdong Province was a rare event. The SARS coronavirus quickly lost 29 nt of information and now 17 of 18 isolates have this deletion. Those with the deletion include isolates from Beijing and Shenzhen in mainland China as well as isolates from patients in Toronto, Bangkok, Singapore, Hong Kong, and Frankfurt. Most of these isolates are linked to the Metropole Hotel and have all 7 of the Metropole Hotel mutations.
The data just released from the Canadian National labs in Winnipeg confirms the early data which showed evidence for the SARS coronavirus in probable and suspect cases as well as patients with symptoms who failed to meet the WHO case definition for suspect or probable cases. Many of their contacts were not interviewed or even identified. Investigators in Toronto as well as Hong Kong are now going back to do more widespread tracing on patients positive for the virus to better understand how far and wide the virus has spread.
The finding of evidence of the SARS virus in patients with a broad spectrum of symptoms suggests the virus has spread quite widely. Molecular epidemiology can help trace the virus as well as mutations. It seems highly unlikely that the 29 nt deletion will be restored and it also seems unlikely that the various point mutations will go away.
In the fall, when flu and cold season returns, the SARS symptoms will be masked by flu and cold symptoms as well as unrelated cases of atypical pneumonia. Co-infection of patients with coronaviruses such as 229E or OC43 and SARS coronavirus will also provide opportunities for novel recombinants. Such recombinants with the infectivity of a cold virus and the potential for causing a fatal pneumonia would represent a formidable challenge.
The mutated SARS coronaviruses are the reservoir of concern for SARS, and the reservoir is right here in River City.
“How mutable is SARS? The mutations allow for species jumping. It is highly adaptable to humans,” said Michael Lai from the University of Southern California’s department of microbiology and immunology."
Troublesome.
Likewise, the effectiveness of human intervention (isolation, quarantine, travel restrictions, etc.) will vary depending on the resources and determination of the people involved. This will also affect the rate of growth in cases (a lower "n").
A huge and little understood variable involves the number of "seeded" cases we may have in the general population .... If these cases become active this fall at the start of the cold/flu season, then "N" will start at a much higher number than we had this spring.
And lastly, of course, any model we build based on publicly available information will be dependent on the accuracy of the data. A government that lies as a matter of national policy, such as China, is useless as a source of information (garbage in, garbage out).
Continuing with the math, which is difficult to do when you have to type T sub 0, etc, T (the period of time one is contagious or "Transmissable") is always unknown, because it is never the same from patient to patient. T typically follows a shallow bell curve of sorts, so we need to determine the mean of the curve from the area of the curve.
This has to be broken into subgroups and then regrouped to get anywhere. I propose the following sub groups:
- 1. Children,
- 2. Teens,
- 3. Walking sick adults (including nonsymptomatic, excluding prior health deficiences),
- 4. Adults who are compromised,
- 5. Group (All ages) requiring Respiratory therapy.
Let's start with the largest group, T (the contagious period), for Group No. 3, is the (# of days they are sick) + (the number of days they shed virus after they are sick) + (the number of days the last shed virus lives on a surface). Therefore T3avg = 7 days + 6 days + 3 days = 16 days for Group 3.
We will continue with T1avg, T2avg, etc.
This will take a tremendous amount of research to find the info for each group, any volunteers??? (We need to use medical research only (no media) available through links at Sarsreference.com.)
Aren't we the ones who complained that the man should not be brought into a court room? Having the hearings in the hospital makes sense to me.
They certainly won't be secret hearings, although they will probably blur the patient's face when they show the tape on CourtTV. LOL!
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