West Nile Virus and blood donors

We ask donors who have visited USA or Canada not to give blood for 28 days after they return to the UK. This is being done to eliminate the risk of transmitting West Nile virus by blood transfusion

What is West Nile Virus?

West Nile virus is a virus which is found in wild birds. It is transmitted from birds to other birds by mosquitoes. Occasionally, the virus is transmitted by the mosquitoes to humans.

West Nile virus has only recently been found in the USA and Canada (1999) but has spread quickly through both countries.

What does West Nile virus do in humans?

The vast majority of humans who are infected with the virus have no symptoms and make a full recovery. A small number of people (about 20%) have a flu like illness with fever and headache and make a full recovery. Very occasionally (less than 1%), the virus may be fatal especially in the elderly and those who have reduced ability to fight infection.

Can West Nile virus be transmitted by blood transfusion?

Yes. There have been a small number of cases reported in the USA and Canada of transmission of West Nile virus to patients by blood from donors who were carrying the virus in their blood at the time of donation.

Fortunately, the period where the virus is found in the blood is short, hence the reason why we are introducing this short period of deferral.

Can I donate blood in future?

Yes - we need you to carry on giving blood. This measure is purely precautionary to make sure that the blood we give to patients is safe. So either please give blood before you go or make sure you do come back to give blood -- every single donation does make a difference.

If you have any questions about this, or would like further explanation or clarification, please see one of our staff at the session.