major surgery there from 1980 to 1985 may have been exposed to the AIDS virus.

Toronto's Hospital For Sick Children is alerting Caribbean physicians about the possibility that children were infected there before the Red Cross began routine screening of blood for HIV.

Ms Claudia Anderson, the hospital's director of public affairs, said children from Jamaica, Trinidad and Tobago, St. Kitts-Nevis, Barbados and other Caribbean islands are in a study of 1,700 patients who may have been exposed to the AIDS virus by blood transfusions received while undergoing open-heart surgery.

Ms Anderson said yesterday she was not sure whether any Bermuda children were among those at risk.

"If in fact there were any children from Bermuda who received open heart surgery here from 1980 to 1985, they will be swept up in the study,'' Ms Anderson told The Royal Gazette . "Family doctors will be receiving letters from the hospital, reminding them that they had referred patients to us and that the children had surgery.'' The hospital is alerting former patients, who are now teenagers or in their early twenties, so they get tested for the HIV virus that causes AIDS, to prevent them passing the disease on to unsuspecting sexual partners.

Bermuda Chief Medical Officer Dr. John Cann said Bermudian children have been referred to the Toronto hospital for heart conditions, but he could not say whether open heart surgery was among the operations performed.

In any case, physicians are aware of the risk of tainted blood in the early 1980s, and it is "extremely unlikely'' Bermudian children who received blood transfusions in that time were not already tested, he said.

He said yesterday he would have to check his records, but he was fairly sure none of Bermuda's HIV-positive children were infected by blood transfusion.

In all, some 17,000 children received blood transfusions during surgery or treatment at the hospital and they may have received HIV-contaminated blood because it was not tested for the virus.

The hospital is focusing on those who received open heart surgery because they received more blood, Ms Anderson said. Still, doctors estimate the risk of infection was only about one in 10,000, she said.

There are 20 HIV-positive children at the hospital who were infected by blood transfusions, she said. Eleven of them had open-heart surgery.