Canadian Blood Services Ready for 2005 West Nile Virus Season; Reminds Canadians it is Safe to Donate
Ottawa, May 17, 2005 – Canadian Blood Services today outlined its 2005 plan for minimizing the risk of West Nile Virus (WNV) for blood transfusion recipients during the upcoming months. This year’s measures build on the success of the past two years and take into consideration ongoing research into the virus. For summer 2005, the Canadian Blood Services WNV Action Plan includes the following measures:
- Continuation of mini-pool testing for WNV on all blood donations, where samples from six units of blood are pooled together for testing;
- Single unit testing as soon as high risk areas are identified – as soon as a higher level of risk is identified in a given health region, single unit testing will immediately be started in that region;
- Deferring ill donors – people who say they feel ill on the day of their donation are deferred from donating and donors are asked to contact Canadian Blood Services if they begin to feel ill in the days following their donation;
- Withdrawal of infected units – Any units that are found to contain WNV will be withdrawn and donors will be deferred from giving blood again for 56 days;
- Surveillance – Canadian Blood Services will continue to work closely with The Canadian Public Health Agency and Hema-Quebec as well as public health units and public health laboratories across the country, to ensure it is immediately aware of the presence of the virus in humans and can act accordingly; and,
- Canceling blood donor clinics in severely affected areas, if required – in the event that WNV activity is higher than expected Canadian Blood Services may take the added precaution of stopping the collection of blood in severely affected areas.
“The 2005 plan provides us with the flexibility to quickly respond when increased WNV risk is identified in any given community,” said Dr. Graham Sher Chief Executive Officer of Canadian Blood Services. “Since the implementation of the test on July 1, 2003, which has been complemented by additional safety measures each year, there have been no known cases of WNV transmission through the blood system.”
This year’s plan differs from last year in that testing for the virus will move from mini-pool testing (six units are pooled prior to testing) to single unit testing (each individual unit is tested) when specific triggers are reached rather than at a pre-determined date. Single unit testing will begin when one positive donation is found in a mini-pool or when recent human cases are identified in the population of a health region at a rate of greater than 1 in 1000 in rural areas or greater than 1 in 2500 in urban areas.
Once single unit testing is begun in an identified area, it may also be initiated in adjacent areas if it is deemed appropriate by Canadian Blood Services medical authorities and if system capacity permits. Mini-pool testing will continue on all donations where single unit testing is not being undertaken.
If single unit testing was initiated because a positive donation was found through mini-pool testing, it will cease when no new positive donors are reported in that health region for a two week period. If single unit testing was initiated because of confirmed human cases of WNV in the local health region population, it will cease when new confirmed human cases, likely acquired locally in the population of that health region over the preceding two weeks, falls below the population trigger of 1 in 1,000 in rural areas or 1 in 2,500 in urban areas.
Canadian Blood Services has carried out WNV testing on every blood donation since July 1, 2003. Between then and April 3 of this year, 1,628,158 blood donations have been tested for WNV. Of these, 14 donations, all confirmed during the summer and fall of 2003, were found to contain the virus. The infected donations were withdrawn and the donors were deferred from giving blood again for 56 days, at which time they were no longer contagious and able to continue donating. No WNV infected donations were found in 2004. There have been no known cases of transfusion-related WNV in Canada since testing began.
WNV continues to be unpredictable and the 2005 WNV action plan will be continuously re-evaluated as the season progresses and new information comes to light. The 2005 WNV plan is explicitly flexible, so that Canadian Blood Services can modify its actions in response to the magnitude and geographic spread of the 2005 WNV epidemic.
Canadian Blood Services is committed to providing Canadians with a safe and secure blood system. In the event of a large or widespread WNV outbreak, the triggers for implementing or discontinuing single unit testing in a health region may have to be modified because the system’s total capacity for single unit testing is limited and Canadian Blood Services must also ensure an adequate blood supply for those who need it. In such a situation of a widespread outbreak, Canadian Blood Services will also consider additional measures, such as suspending collections in areas of intense human activity while increasing collections in areas of no or less activity.
“We want donors and recipients to continue to feel confident in their blood system. A greater risk than West Nile Virus is that Canadians will not continue to donate and there will be a blood shortage.” said Dr. Sher. “Remember…you cannot become infected with WNV by giving blood and mosquito bites do not disqualify you from donating.”
Call 1 888 2 DONATE to make an appointment.
About Canadian Blood Services
Canadian Blood Services is a national, not-for-profit charitable organization that manages the blood supply in all provinces and territories outside of Quebec and oversees the country's Unrelated Bone Marrow Donor Registry. Canadian Blood Services operates 42 permanent collection sites and more than 15,000 donor clinics annually. The Provincial and Territorial Ministers of Health provide operational funding to Canadian Blood Services. The federal government, through Health Canada, is responsible for regulating the blood system. For more information, please visit our Web site at www.bloodservices.ca.
For further information contact:
Media Room Relations Manager
Canadian Blood Services
For additional information on West Nile Virus, including a detailed backgrounder on the Canadian Blood Services 2005 WNV Action Plan, click here.