West Nile Virus Strikes Canada
Kitchener, Ont. - Canadian Blood Services is investigating three cases of West Nile virus likely contracted by Ontario residents through blood transfusions, including a Kitchener, Ont. woman who died of the virus in November.
Test results point to a transfusion of tainted blood in the death of Joyce Kimmel, 57, although the investigation is still ongoing.
"It's highly likely that this was transfusion transmitted," Heather Hume, executive medical director of Canadian Blood Services, said Thursday.
Ms. Kimmel died Nov. 21 of encephalitis, a potentially deadly brain swelling triggered in rare cases by the West Nile virus.
Blood tests confirmed she was infected with the West Nile virus.
If it is confirmed that the Kitchener woman contracted the virus through transfusions, she would be the first in Canada. There have been 13 such cases confirmed in the United States.
Two other Ontario residents who contracted West Nile virus are also being investigated. Both received blood transfusions in the four weeks prior to the onset of symptoms, Dr. Hume said.
Dr. Hume refused to reveal any other details about the patients due to confidentiality rules. She could not say whether they died or became seriously ill from the virus.
Blood transfusions are "highly likely" the cause of infection in one case, Dr. Hume said.
Dr. Hume said it's impossible to be entirely sure a person contracted West Nile virus from blood transfusions because even if a donor tests positive for the virus, they may not have been infected at the time of donating blood.
In the case of Ms. Kimmel, Dr. Hume said the majority of donors have been screened for the virus and one tested positive for West Nile.
Canadian Blood Services is preparing for the coming mosquito season this summer with new blood testing equipment that should be ready for July 1, Dr. Hume said. Three labs are being renovated to house the large equipment that will screen blood for West Nile Virus.
No screening test for blood existed at the time Ms. Kimmel was infected.
"The plan is to test every blood donation," Dr. Hume said.
She said it has not yet been decided if blood will be screened for West Nile only during mosquito season or the entire year.
Dr. Hume said the blood agency is also stockpiling enough frozen blood product to last the mosquito season if the new machines are not up and running this summer.
Plasma can be frozen, but red blood cells and platelets cannot. In the event the screening machines aren't ready, Dr. Hume said they're considering another test that can be done in small batches for high-risk patients who need red blood cells or platelets.
Last year, there were 393 cases of West Nile reported in Ontario.
The West Nile virus, which was unknown in North America until 1999, is most-commonly transmitted to humans through the bite of an infected mosquito, but it can also be spread via breast milk, organ transplant and blood transfusions.
The majority of people who contract the virus - upwards of 80 per cent - do not get sick. The virus only lives in the bloodstream for a few days.
Copyright © 2003 Bell Globemedia Interactive Inc.
This article posted March 9, 2003.