Giving Blood

[BobbyBobBob]

I gave blood the other day and was asked numerous questions about potential harms of diseases.

It popped into my head that, say for example you had unprotected sex or shared a needle (potentially contracting HIV) a couple of days before giving blood. Could they still trace things like HIV at that early stage when they test your donation? My understanding is that this disease has a lengthy incubation period.

So what happens if you shows up negative and further down the line after you've already given blood you get it?

[Sqad]

PP...right ...thanks.

[sandyRoe]

Is there no altruistic blood donation in the USA? Paying donors was a recipe for trouble.

[slaney]

There is individual variation but for the first 9-12 days after HIV infection the virus remains local and there is no true viraemia, that is it does not enter the bloodstream. This is called the eclipse phase, and risk of transmission by blood transfusion during this phase is low.
Thereafter in the next phases - the latent phase or window phase one is infectious.

New tests have now reduced the window period from 6 weeks to 4 weeks.

Since testing was introduced in 1985 in the UK there have only been only two documented cases of HIV transmission by blood transfusion, the last occurring in 2002.
This is against a background of two million donations a year.