SARS SPREADS IN CHINA (Is the bug out of the box again)

NATURE ^ | 04-27-04 | HELEN PEARSON

[Mother Abigail]

Health officials are investigating another four suspected cases of SARS in China. The cases bring the total number affected to eight, with more expected.

All of the cases can be traced to a laboratory at the Beijing Center for Disease Control and Prevention, China, where the coronavirus that causes SARS (severe acute respiratory syndrome) was being studied. The first person to fall ill, on 25 March, was a 26-year-old female researcher who had worked in the lab.

[Mother Abigail]

WHAT WE KNOW

The bug got out of the box at the National Institute of Virology in Beijing.

Two of the recently reported cases were conducting research at the laboratory: a 26 year old female postgraduate student from Anhui Province, and a 31 year old man.

The dates of symptom onset in the 2 cases were separated by 23 days, suggesting that more than one opportunity for exposure may have occurred in the laboratory from mid-March through early April 2004.

Authorities have closed the virology institute and placed its more than 200 employees under medical observation. Numerous environmental samples from the laboratory have been taken to help assess possible sources of contamination, and these samples will be shared with WHO.

From the information currently available, there is now evidence of 3 generations of transmission.

The 1st generation involved the index case from Anhui, and possibly a 2nd "1st-generation" case, the postdoctoral student from Beijing whose onset of illness was 23 days after the onset of illness of the index case from Anhui.

The 2nd generation included the mother of the index case from Anhui and the nurse who cared for the index case from Anhui while she was hospitalized in Beijing, and possibly the physicians who cared for her while hospitalized in Anhui.

The 3rd generation of cases are the family members of the nurse (from the 2nd generation), a patient hospitalized in the same ward as the nurse before SARS was identified as a possible diagnosis for the nurse's illness, and a close contact of one of the physicians who treated the index patient in Anhui.

This pattern of nosocomial spread due to lack of early identification of SARS as a possible diagnosis is very reminiscent of the outbreak in 2003.

[Mother Abigail]

Ping

[dc-zoo]

Good to see you back here again. Not good to see sars raising its ugly head again though. So many of us on the sars threads last year were wondering where you went.

[jacquej]

I am happy to see that you are back as well. I will be watching this outbreak very closely, and hoping that it is stopped, somehow.

I had hoped it was just a fluke before, but it seems not.

[Mother Abigail]

It is good to be back in the land of latte.

HEFEI, April 27 (Xinhuanet) -- The SARS patient in east China's Anhui Province, surnamed Song, is now in stable condition, Zhu Qixing, head of the No.1 Hospital affiliated to the Anhui University of Medical Sciences, in an interview with Xinhua on Tuesday.

    "At this stage Song's disease is no longer infectious," said Zhu.

However, Zhu said, doctors would continue to tighten monitoring over and medical treatment on Song until she fully recovers.

    Song, aged 26, who is still receiving medical treatment at the hospital's ICU, last Saturday stopped taking hormone and medicine to raise blood pressure, and her temperature has returned to normal, according to Zhu.

    "Song's temperature at 9 a.m. on Tuesday was 36 degrees Celsius.She is in a fine mood and can do some exercises out of bed," said Zhu.

    The Chinese Ministry of Health announced two SARS cases in Anhui last Friday afternoon. The other SARS patient in Anhui was Song's mother, who died on April 19.

    Song, who does her postgraduate courses with the Anhui University of Medical Sciences, studied at a Beijing-based research institute of virus diseases under the Chinese Center for Disease Prevention and Control (CDC) from March 7 to 22.

    On March 23, Song went back to Hefei, capital of Anhui Province,by train and then returned to Beijing by train after complaining of fever on March 25.

Later, she went to see doctors in Beijing and Huainan City of Anhui Province.

On April 4, she was transferred to the No. 1 Hospital under the Anhui University of Medical Sciences for further treatment.

[Mother Abigail]

Health authorities decided yesterday to take yet another throat secretion sample from a man who visited Beijing last week and developed a fever upon returning to Taiwan to confirm that he has not been infected with the severe acute respiratory syndrome virus.

This is the third time that a throat secretion sample from the researcher who works at a private Taiwan biotechnology company is tested for SARS since his return Saturday evening. The first two tests were negative.

The researcher, surnamed Hung, has been quarantined and put under observation at a Taoyuan hospital since he was discovered to have a temperature higher than 38 degrees Celsius Saturday evening upon returning from his week-long visit to Beijing.

Shih Wen-yi (¬I¤å»ö), deputy director-general of the Center for Disease Control under the Department of Health, said yesterday that the researcher will be allowed to leave the hospital and go home if his temperature remains normal, he shows no other SARS-related symptoms, and he tests negative for the SARS virus. The results of the third test are expected to come out after 4 p.m., according to Shih.

The reason Hung is being tested three times is that previous cases have shown that SARS symptoms sometimes resurface after a person's temperature returns to normal and the person is declared SARS free, said CDC Director-General Su Ih-jen (Ĭ¯q¤¯) during a press conference held Sunday.

While in Beijing between April 19-24, Hung visited a lab where one of the latest SARS cases in China had been reported. His case has drawn much attention from Taiwan's health authorities as it has occurred at a time when the potentially fatal flu-like disease has been showing signs of resurgence in China, particularly in Beijing, since last week.

This is the first case in Taiwan of an individual being monitored for possible SARS infection since the outbreaks of the atypical pneumonia in China subsided last summer.

[Judith Anne]

If the SARS virus escaped from a lab, does this mean that there are no naturally occurring cases this year?

[Mother Abigail]

I believe not, however this is now the 3rd incident of SARS transmission within a laboratory working on SARS research.

The first 2 occurred in Singapore and Taiwan since the 2003 outbreak.

It seems as though laboratory exposure is a higher risk factor than the possible zoonotic exposure. -

[Judith Anne]

I recall reading that over a hundred were quarantined from this latest escape, and I'm wondering if any how many will come down with it...

[Mother Abigail]

The number is now around 1000.

The wild card is the train trips the index case took while infectious.


On 6 Mar 2004, there was travel on the Hefei - Beijing line 1410 train

On 23 Mar 2004, there was travel on the Beijing - Hefei T63 "inferior" train [?second class]

On 27 Mar 2004, there was travel on the Hefei - Beijing T64 "inferior" train of 17 compartments [?second class]

On 2 Apr 2004 there was travel on the Beijing - Huai Nan 1409 train of 13 compartments

All passengers who were riding on the above-mentioned coaches and compartments: please report to your local disease control office for medical evaluation/consultation.

[Judith Anne]

Oh! How long is the incubation? I thought it was about three weeks, but could be longer or shorter.

[Threepwood]

Three weeks? It's more like 4-10 days, and outside a hospital setting it doesn't have real legs. I'm not going to worry too much this time round.

[Judith Anne]

Me either, with one slight reservation, the well-known tendency of the Chinese to hide information.

[dc-zoo]

1000 quarantined? Very unfortunate that this all originated from a research lab.

[Threepwood]

That's not unreasonable, but I think they learned their lesson. It's funny, but one of the only controvesrial topics that can be freely discussed and subjected to agressive journalism in China today is public health. Weird no?

[Judith Anne]

You're more optimistic about the Chinese learning their lesson than I am; I'll watch for news, but I'm not thinking we'll have another outbreak outside of China this year, though I certainly could be wrong.

[Mother Abigail]

During the outbreak of SARS in 2003, the primary mode of viral transmission was to close contacts when respiratory precautions were not taken.

According to the information available, the 2 probable cases (the index case from Anhui and the nurse who cared for her in a Beijing hospital) were not treated as suspected cases of SARS for some time prior to the implementation of infection control procedures that would have minimized the spread of the SARS Co-V.

The index case had onset of illness on 25 Mar 2004, her mother on 8 Apr 2004; the 1st indication of classification as suspected case(s) of SARS appears to be 19 Apr 2004 upon the death of the index case's mother.

The date of onset of illness in the nurse was 22 Apr 2004, and that of the additional postdoctoral student working in the laboratory with the index case was 17 Apr 2004 (he was classified as a suspected case when initially seen).

Hence, it appears that in the period 25 Mar 2004 through 19 Apr 2004, the index case and her mother were clinically ill with probable SARS CoV infection, and were potentially infectious to others in their contact environment, including during travel on trains between Beijing and Anhui province, and during hospitalization in general clinical care wards without isolation.

The challenge will be to identify and isolate those individuals who were infected through close contact with the above-mentioned cases so as to interrupt further transmission of the SARS Co-V.

[Mother Abigail]

China has isolated more than 600 people in Beijing as it attempts to sever a chain of infection that leaked from a laboratory and could spread as tens of millions travel the country for the annual May Day holidays.

Four teams of World Health Organization experts were due in China this week to help the government investigate the laboratory accident, to track down people exposed, control infection in hospitals and monitor the situation in the eastern province of Anhui, where one woman died.

The WHO lauded the widening quarantine, saying it showed the government was taking the right steps to check the spread of Severe Acute Respiratory Syndrome before the week-long public holiday starting on May 1.

Across the country, authorities have stepped up surveillance against the disease, which is highly contagious.

Thailand was screening passengers arriving by air from Beijing as a precaution, a health official said.

The 600 people quarantined, including 24 staff at the national center for disease control, were under collective isolation or confined to their homes, the Beijing News said.

More than 180 staff of the National Institute of Virology, where a medical student who caught SARS is believed to have engaged in research on live samples of the virus, were already sequestered, most at a resort north of Beijing.

(There is mixed reporting on the number of contacts quarantined in Anhui.)

[Mother Abigail]

Joseph P Dudley, PhD
Senior Analyst, Biosecurity & Agriculture

Although SARS obviously didn't originate in rats, the current evidence seems to indicate that what we are witnessing and tracking at this time is a significant evolutionary event involving the process of the tentative early stages of the establishment ["adaptation"] of a newly-mutated viral pathogen (the SARS coronavirus) in a new stable reservoir host (rats, cats, humans, etc.).

If we are fortunate, the SARS virus, in its current form, may not be able to establish itself as a self-sustaining zoonotic pathogen within rat populations, and the disease may only occur in rats as a transient and dead-end secondary host (in which case, the closing of wildlife street markets -- for raccoons, dogs, palm civets, etc. -- could successfully prevent subsequent outbreaks). The current data do suggest that this may in fact be the case at present.

It cannot be ruled out that the hypothesized role of rats in the Amoy Gardens outbreak could have involved mechanical transmission rather than urine/fecal contamination (as might have occurred had a rat crawled/swam out of a SARS-contaminated toilet and then tried -- successfully or unsuccessfully -- to exit the toilet room by means of the ventilation fan opening or by means of a ventilation shaft).

It seems possible, however, that if the intensive rat-eradication efforts undertaken at the sites in Guangzhou or Hong Kong, where SARS outbreaks occurred, were, in fact, successful, or nearly so, we could still have a possibility of latent SARS infections circulating in such a very small number of individual rats that we would not expect the disease to have revealed its presence in urban rat populations at this early date; at least until the next time there is a recurrence of the reported scenario in Guangzhou this year, in which several rats infected with SARS were trapped in an apartment of an isolated SARS victim who has no known contacts with any of the suspected wildlife hosts for the SARS virus.

For all of these reasons, it is extremely important for any and all potential SARS reservoirs and transmission mechanisms to be thoroughly, and exhaustively, investigated. We must also recognize that what is true for the SARS virus today may not necessarily be true tomorrow, as demonstrated over the past year with the avian influenza A (H5N1) virus.

Demonstration of past recombination events in the SARS-CoV lineage indicates this virus has a clear potential for rapid unpredictable change that makes this pathogen an extremely challenging adversary for drug and vaccine development well as for public health management

[Mother Abigail]

RE: Naturally occurring cases

Jan 04, 2004

Rats may prove to be the missing link in a suspected case of SARS (severe acute respiratory syndrome) first reported in Guangzhou, capital city of South China's Guangdong Province.

A mutated strain of the deadly virus was diagnosed on a 32-year-old freelance television producer, making him the first suspected SARS patient on the mainland since last May.

However, health officials and top experts reached by China Daily yesterday cautioned that more laboratory tests must be done before any confirmation can be made.

New details surfaced when local Guangzhou media reported the patient had set traps for rats that had invaded his apartment before he showed SARS symptoms. Laboratory tests have shown that some of the rats caught in his apartment also tested positive for SARS.

However, this does not necessarily mean that the rats are the definitive source of the new strain of coronavirus, Liu Qiyong, an expert on epidemics from the Chinese Centre for Diseases Control and Prevention (CDC), said yesterday.

The result may have been caused by some other strain of coronavirus carried by the rats, since there is a slight difference from the kind that caused the SARS outbreak in human beings last spring, Liu said. In fact, other strains have been found in rats, as well as in other animals long before the new case emerged.