Toronto Knows Where, Not Why, of New SARS Outbreak

The number of Toronto-area residents under quarantine for SARS expanded to more than 3,400 Tuesday as authorities worked to unravel the biggest mystery of the new outbreak here: how an elderly surgery patient who started the latest cluster contracted the fatal disease.

Canadian health officials said only that they had established a link between the 96-year-old man, who fell ill with severe acute respiratory syndrome after undergoing surgery in a hospital thought to be free of the disease, and the cluster of cases that plagued Toronto earlier this year.

“They’ve done an in-depth investigation. They’ve discovered a link,” said Tanya Cholakov, media coordinator for the Ministry of Health and Long-Term Care. “I can’t get into any details, but I can tell you he’s considered linked to the original cluster.”

Joe Mihevc, chairman of the Toronto Board of Health, said such a link would be “very important information” because it would indicate there are no new, unanticipated sources of infection outside the hospitals, families and circles of friends already documented with the disease.

“If a link has been established, that is great news, because it means the chain [of cases] can be maintained. It means you can basically start to put a net around all the different possibilities,” Mihevc said.

For days, health officials have said they are relatively certain that the latest outbreak, which as of Tuesday had expanded to include 12 active probable cases, could be traced to a single source: the elderly man, who became sick with a pneumonia-like illness after undergoing pelvic surgery at North York General Hospital. The man died May 1.

Six other patients in the man’s ward contracted the disease between April 22 and May 23 and spread it to 11 family members and 10 health-care workers. One patient from the same ward apparently carried it to a rehabilitation hospital.

Health officials have said no special precautions were taken to isolate the man because he had no known links to SARS cases and was thought to have developed a case of common postoperative pneumonia.

But a central question has long remained unanswered: How did the man get SARS in the first place in a hospital ward that was thought to be free of the disease?

“One of the things I’ve always said is that hospitals are safe for people outside of SARS units, and I really mean that,” Donald Low, chief microbiologist at Mount Sinai Hospital, said at a news conference over the weekend. “Here, I am wrong. Here we had a case occur, we don’t know what the link is, and we have to find the link.”

Low worked with a team of epidemiologists at North York General Hospital throughout the day Tuesday to solve the mystery; he could not be reached for comment to discuss the reports of a new link. Likewise, Ontario’s public health commissioner, Colin D’Cunha, said there was still no final answer about the elderly man’s exposure.

“The investigation is still underway. There’s a bunch of people at North York hospital today trying to determine that,” he said.

The issue of how the elderly man got SARS is important because it could shed light on the adequacy of protection measures within the health-care system -- or raise the possibility of avenues of infection, such as airborne transmission, previously thought unlikely.

“What we have known until now about that 96-year-old man is that it happened in a hospital setting,” Mihevc said. “We know that it happened sometime around the end of April, beginning of May. We know that it’s the index case for this new round and we can trace all the cases, probable and suspect, back to him. And we know he passed away.

“But we don’t know how he got it. That’s the reality. We do not have his contact. It’s a puzzle.”

However, health-care officials feel sure they have “a net over all the possibilities,” Mihevc said. “It could be a health-care person who went from one room to another room and was not properly masked.”

There has been increasing criticism in recent days that Toronto let down its guard too quickly after the first SARS outbreak this spring, which led to a full-scale health alert and travel advisories from the World Health Organization and the U.S. Centers for Disease Control and Prevention.

Health-care officials worked vigorously to isolate and control the outbreak and had halted the development of new cases by mid-May, leading the WHO to remove the city from its list of SARS-affected areas.

At that time, some hospitals might have eased strict precautions involving disinfection, isolation and protective gear, believing that enough time had elapsed to preclude any new SARS cases.

Low said that in many cases, hospital workers outside designated SARS units were allowed to stop wearing masks after May 8.

“The two incubation periods had passed in hospitals, we hadn’t recognized any new disease, [so we] closed the book on SARS,” Low said.

“Looking back now, we shouldn’t have closed the book. We should have gone through our hospitals with a fine-toothed comb and made sure that there wasn’t someone there who may well have SARS. If we had done that, we might not be in this position today.”

But D’Cunha said guidelines that allowed hospitals to go into a “new normal” phase came 20 days after the onset of the last SARS case and after the WHO had lifted its advisory.

The new cases “crept under the radar screen [while] we were still ramping up our [new] control procedures,” he said, adding that it would be unfair to consider the “new normal” operating procedures inadequate.

“I don’t believe necessarily that hospitals were off their guard,” he said. “But the real take-home message is we need to be on our guard into the future -- as long as there’s a case of SARS somewhere in the world.”