TORONTO -- Canadian health authorities are investigating whether a medical resident who worked in a Toronto hospital maternity ward has SARS, an official said Friday in a setback to the city's efforts to control a second outbreak of the disease.
Globally, only a dribble of new SARS cases were reported Friday in the hardest-hit areas -- China, Taiwan and Hong Kong -- during a worldwide trend of remission. But Thailand, which has been unscathed by the epidemic, reported a new infection, only its ninth.
In Toronto, Dr. Donald Low, a microbiologist at Mount Sinai Hospital, said the resident likely was exposed to severe acute respiratory syndrome on May 23 at another hospital, but went 12 days before first showing symptoms.
That is two days longer than what health authorities believe is the incubation period for the disease.
The male resident showed no symptoms of SARS when he helped deliver twins during a daylong shift Wednesday at Mount Sinai's labor and delivery ward, Low said. Symptoms first appeared the next day, Low said.
Health officials have told five women to go into home quarantine with their newborn babies, while another 20 from the ward were under surveillance, Low said.
The news was a setback to the city's efforts to control a second outbreak of SARS in recent weeks, following an initial cluster in March and April.
Health officials said Thursday the illness appeared to be under control and reported 68 probable cases, up one from the previous day.
They also rolled back the death toll to 31 after rechecking the hospital records of a 60-year-old man who died May 20 and was initially considered a SARS victim.
Dr. James Young, the Ontario commissioner of public safety, said further review of the case showed the man died of other causes.
Worldwide, the contagious lung disease has killed at least 778 of the more than 8,300 people infected since the virus emerged in southern China in November.
A World Health Organization official said Thursday the SARS outbreak was "over its peak" around the world, including in China, which has suffered the highest toll, with 338 deaths.
China's daily figures have hovered in single digits for more than a week, dropping from a high of 150 cases a day. China on Friday reported two new SARS deaths and one new case.
Hong Kong's daily reports of infections have been in single digits for more than a month. It announced two new cases on Friday, and two fatalities, pushing its death toll to 286.
In Taiwan, two medical workers tested positive for SARS at a hospital that had yet to report any cases. In the past week, the island's daily tally of new cases has been in the single digits and no fatalities have been reported in nine days, keeping the death toll at 81.
Toronto authorities believed they had the illness under control after the initial cluster mostly disappeared by mid-May. An undiagnosed case at North York General Hospital led to a further spread among other patients, family members and health care workers.
The second cluster of SARS cases landed Toronto back on a WHO list of SARS-affected cities or regions, although the U.N. agency has not reissued a travel advisory for Toronto. A previous advisory was rescinded after a week when Canadian officials complained it was unwarranted and promised better screening of international travelers for SARS.
The SARS outbreak has hurt Toronto's crucial convention and tourism industry, with hotels, restaurants and theaters saying business is down.
Young, the public safety commissioner, said the latest outbreak appeared under control, but hospital workers will continue wearing protective garb, including gloves, masks and gowns to avoid exposure to any possible cases.
Health care workers have complained authorities dropped their vigilance in May in a rush to proclaim Toronto safe after the initial outbreak of SARS.
"We have to keep looking and looking and looking and assume it's there," Young said. "We're going to be very cautious and very vigilant because it's a very difficult virus."