Ontario's commissioner of public health, Dr. Colin D'Cunha, says he suspects that an additional case of Severe Acute Respiratory Syndrome (SARS) has been identified in Toronto.

There are currently 15 suspected cases in Ontario. A further 14 health care workers at a Toronto hospital are under observation.

On Tuesday Ontario Health Minister Tony Clement said he was ordering the shutdown of the hospital emergency room in east Toronto.

Dr. Colin D'Cunha

The ER at Scarborough Grace Hospital was closed on the weekend, after a third person died of a respiratory disease, believed to be SARS.

Clement says he wants the hospital to concentrate on making sure that no new patients are exposed to the illness.

D'Cunha is quoted in a news release on the ministry's Web site as saying the cases being monitored are "the result of unprotected contact with initial cases before we were aware of SARS. Now, health care staff across the province are alert to the virus and are able to protect themselves and their patients to prevent further infection."

SARS is contracted through close contact with a person with the disease, including having cared for, lived with or had face-to-face contact with them; or having had direct contact with respiratory secretions and body fluids of such a person.

The people most at risk include those who have recently travelled to Guandong province in China, Hong Kong, Vietnam and Singapore.