Posted on 04/20/2003 9:05:28 AM PDT by CathyRyan
TORONTO - In a frightening new twist, health officials say the SARS virus is able to survive outside the human body -- and pose a danger -- for at least 24 hours, in addition to being spread by face-to-face contact.
The tenacity of the mysterious severe acute respiratory syndrome virus may explain a new cluster of infections in Toronto.
Hospital workers there have caught the disease despite being protected from head to toe by gowns, gloves, masks and eye shields.
"We know that the (precautionary) measures that have been recommended should be adequate to deal with those (patients)," said Dr. Andrew Simor, head of microbiology at Toronto's Sunnybrook Hospital.
"But we're also impressed with just how easily the virus is spread, how it might contaminate the environment."
Simor added that, in a Friday night conference call with Health Canada and the U.S. Centers for Disease Control and Prevention, in Atlanta, Ga., a CDC expert surprised participants by revealing that the virus can remain alive and potent on inanimate objects much longer than previously thought.
"What the CDC mentioned to us last night was that, in their studies, they found that you could still culture viable virus from surfaces after as much as 24 hours, which is longer than we normally expect viruses to be able to survive in the environment," he said.
In a statement Saturday, the World Health Organization said it is also concerned about the possibility of environmental transmission. It's looking closely at how SARS spread through a Hong Kong apartment complex, where the building's sewage system, which carried the virus from an infected person.
However, the health body concluded there is "little risk" that environmental causes are behind a probable SARS case in a Toronto condominium. The incubation period has passed in the building with no further cases, the WHO noted.
The new cluster erupted at Toronto's Sunnybrook and Women's College Health Sciences Centre, which has treated about half the region's SARS patients over the past month. It has 20 to 25 SARS patients admitted at any given time.
As of Saturday afternoon, four staff members, including at least one doctor, a nurse and a respiratory therapist, were in hospital and almost certainly have SARS. Another eight hospital staff members were sent into home quarantine as potential cases.
Hospital officials believe the infections occurred during difficult intubations involving two patients, including one last Sunday that took four hours. Intubation involves placing a tube down a patient's throat to facilitate breathing.
Both patients are now believed to be so-called super spreaders, or viral shedders, who are much more infectious than average SARS patients.
Some staff started feeling symptoms associated with SARS on Wednesday and Thursday. Senior hospital staff became aware of the threat late Thursday night.
Dr. Mary Vearncombe, the hospital's head of infection, prevention and control, said one worker's eye shield slipped during the Sunday intubation procedure but there was no other known breach of the staff's "full-droplet" protection. That protection includes gowns, gloves, eye shields and N-95 masks.
"We were using what both Health Canada and the Centers for Disease Control consider to be maximal precautions for these patients," she said, adding it's possible some potentially infected staff were not present at the intubations.
That raises serious questions about how the virus was spread and whether the current precautions are enough to protect health care workers.
Dr. Gerry Predy, the Edmonton health region's medical officer of health, said the CDC discovery shows how important hand washing and cleanliness are in preventing the spread of a virus such as SARS.
Viruses often spread when an infected person touches a door handle or some other object, after moistening a finger by touching their eye or nose, he explained. Then a healthy person first touches the door handle, then their own eye, and they have the infection.
But where SARS can survive on a door knob for 24 hours, a common cold virus can only survive for two to four hours, Predy said, so more SARS infections may be caused by lapses in hygiene than in droplets coughed into the air.
The new cluster will further tax Toronto's almost-paralysed health care system.
Instead of easing operating restrictions as it had planned, Sunnybrook has effectively closed its critical care, cardiovascular intensive care and SARS units for 10 days as a precaution.
"It's a huge burden on the system,'' said Leo Steven, the hospital's chief executive. He said Sunnybrook, probably the biggest trauma centre in Canada, will have to send trauma patients to hospitals in Toronto, Hamilton and beyond.
Vearncombe predicted that even if containment measures are successful, Canada will have to learn to live with the SARS threat.
"I have some level of optimism that we can contain it in Toronto," she told reporters.
"I have no optimism that we can contain it in developing areas of the world like mainland China so we will continue to import cases and we're going to have to remain absolutely vigilant."
Canada has about 300 probable and suspect cases of SARS in six provinces, mostly in Ontario.
The World Health Organization reported 86 new cases Saturday, bringing the global total to more than 3,500. To date, 182 people have died.
But thanks for the response anyway. I have a really bad feeling about this disease, just as I did about AIDS in 1981. I think this is not going to go away. FReegards.
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