The respite was brief. 1 month after appearing to have contained an outbreak of severe acute respiratory syndrome (SARS), public health officials in Canada's largest city find themselves revisiting their worst nightmares.“It's not over”, disconcerted Toronto Mount Sinai Hospital chief microbiologist Donald Low told reporters on May 25 as the number of cases began to mount from the new institutional outbreak.The disturbing numbers include eight new “probable” cases, including a 96-year-old man and a 90-year-old woman who died recently, as well as 26 “suspect” cases.Officials have traced the outbreak to the 96-year-old man, who died on May 1 while being treated for a fractured pelvis at Toronto's North York General Hospital. It's believed he developed SARS while in hospital but was diagnosed as having routine postoperative pneumonia and was not kept in isolation.Although officials are at a loss to explain how the man might have possibly become infected with SARS, it seems he infected several other patients in his ward, including a woman who was later transferred to the St John's Rehabilitation Hospital, where she, in turn, infected a health-care worker and several other patients.Essentially, the outbreak went undetected for weeks but has since got to the point where several hospital wards have been closed, while patients and visitors who entered the North York General, St John's, the Scarborough General or the neurosurgical unit at St Michael's Hospital from mid-May onwards have been asked to go into quarantine.With the latest deaths, the Canadian SARS toll is now 27 and weary Torontonians are again reaching for facemasks and facing restrictions on visiting family members in hospital. The city is also fretting that WHO will soon revisit its decision to lift its advisory against travel to Toronto and place it back on its list of dangerous destinations. “It wouldn't surprise me if they put us back on”, said Ontario commission of public health Colin D'Cunha.Meanwhile, the US Centers for Disease Control and Prevention have already reinstated their travel alert to Toronto, telling US travellers to avoid hospitals if at all possible during their visits.WHO, on the other hand, has not indicated its intention regarding Toronto, but has lifted its advisory against travel to Hong Kong and the neighbouring Guangdong province of China. In its May 26 update on SARS, WHO say the worldwide death toll is now 725, and the cumulative number of cases is now 8202 in 28 countries.