Why can’t you donate blood if you have had a transfusion in the past

[MiriamMay]

Like the woman in this BBC article, I am not able to give blood because I had a blood transfusion after giving birth.

I don’t understand why this is though. There’s been quite a bit in the news lately about there being a shortage of blood donations. I really don’t understand why having received a transfusion in the past means you can’t donate blood in the future.

BBC News

The NHS explains. I cannot give blood because I had a transfusion after a very nasty miscarriage in 1981. The rule is to prevent passing on variant CJD. I doubt I could ever give blood anyway as I had hepatitis as a child.

This is a really good explanation. It is basically risk vs reward and supply vs demand.

When I first gave blood (late 90s) a man could not donate if he had ever had sex with another man. Now there is just a “not in the first 3 months” rule.

So they do change the rules as they understand the risks better.

@VioletHamilton you just made me ember. I was on the Antony Nolan Bone Marrow register from about 1985 and came up as a close match/potential donor in the early 90s. Had to go to a London hospital ( Royal Free maybe?) to give some blood, have all the procedures explained etc. I was asked if I’d had a blood transfusion — yes— so was asked if I’d be willing to give extra blood for additional testing. Stupidly didn’t ask why, or what sort of testing.

Those rules have changed, and you would likely now be allowed to donate in the USA.
https://www.redcross.org/about-us/news-and-events/news/2022/more-people-now-eligible-to-give-blood-with-the-red-cross.html

The rules have also changed in Australia.
https://www.lifeblood.com.au/news-and-stories/vital-reads/uk-blood-donation-mad-cow-rule-has-changed-for-good

I am a US resident who formerly lived in the UK and received a blood transfusion there, and I donate regularly here in the US.

Is the risk that transfused blood might be contaminated greater than my own blood being contaminated?

You have clearly understood what your neighbour has said!

No, but once you've had a transfusion then your blood has all your original risk, plus all your donor's risk.

There is no test to tell if someone has CJD, therefore to limit the potential negative outcomes they stop you donating once you've received donated blood. The blood you received in 2017 won't have been around from 1980 however it's possible that the people who donated the blood were, ergo they'd be a risk of carrying it.
Blood donation only has a finite budget and they have to balance that with risk.

@VioletHamilton the reason is because bone marrow matches/donors are so rare that the risk of the patient dying far out ways the risk of passing it on.

Lots of health conditions and medications preclude you from giving blood too.

I'd need to be off my current medication for a year before I could donate (although I also have an autoimmune condition so I am out on that score too)

I wonder what happens if you give blood and then later discover you have a condition? Is it in the blood you donated? (I am being very simplistic here I am sure it's a lot more complex than that but are there people who have donated blood and then gone on to discover they have a condition that wouldn't have been screened for?)

I'm sure it does but patient safety is sadly not always paramount. We wouldn't be in the middle of an infected blood scandal if it were.

Nrtft but I thought it was because not everything can be tested for and you may have contracted something from your previous donation like mad cows disease.

i lived overseas for many years and wasn’t allowed to donate blood because I grew up in England so ran the risk of being exposed to mad cows disease.

Although if you grew up in England and had an English transplant I’m not sure what the extra risk is unless the person who originally donated blood was higher risk as I thought exposure to CJD was between certain years, again although given all the lies and secrecy about it at the time I wouldn’t be surprised if there is something we are not being told.

If I needed a blood transfusion and you gave me the choice between a bag from
Class 1: someone who'd had a transfusion in the past or
Class 2: someone who hadn't

then all other things being equal I'd take the Class 2 bag thank you. And at the moment bag 2 is always available, so we don't need to take donations from class 1 at all.

But if I need bone marrow, or a kidney, then it's entirely possible that there won't be a suitable class 2 organ on offer. In which case if there's a class 1 organ available I'll grab it with both hands, and take the small additional risk on the chin because it certainly beats the alternative.

I gave blood after a blood transfusion. It was in 1998, 3 yrs after my transfusion.
Then they changed the rules.

If you have a blood transfusion it will have come from multiple donors. Whilst they screen it, they can't detect all possible diseases including those not identified yet, meaning a recipient has a higher risk of infections etc than a non recipient. They are given for good reason so not a reason to avoid transfusion but the risk is too high to donate

If you inform the blood service that you’ve developed a condition within a period of time since a donation they can track who received your blood products. I don’t know the exact ins and outs of it but they have records going back at least 30 years (more since the infected blood enquiry as they aren’t getting rid of old records currently)

We’ve had an instance recently where a donor found out they had cancer a few months after donating (not awaiting tests/no symptoms at the time of donating) so the medical team were able to follow up with the doctors of the patients who received their blood products.

This is why they always ask if you’re fit and well at the time of donating and I believe they say to inform them if you develop any illness (even if it’s D&V or similar) within 2 weeks of donating.

The reason is specifically linked to vCJD, not any other potential viruses, hepatitis etc.

Thank you so much. That's really explained something I couldn't get my brain around.

That's also really interesting to hear about if you go on to develop even a "bog standard" illness shortly after donation.

I've had 7 units in total. Including my own chance, that's 8 chances of getting infected.

I had a blood transfusion in April due to severe anaemia, I feel quite scared now as felt reassured when I was told it was screened extensively. My haematologist did say it wasn't without risks but omg , vCJD, it doesn't get much worse, I didn't know that couldn't be screened for 😯

There is a misunderstanding here.

The tests will be a crossmatch of unit to patient sample. It will be group specific or O Neg issued.

All micro and virology tests are completed long before it reaches a clinical transfusion lab.

Because the balance of risk is different.

Getting a match for a bone marrow transplant is difficult - even close relatives might not match and even searching registers internationally might not find one.

And as a bone marrow transplant carries the risk of death, it's only ever carried out when there is no alternative treatment and the disease being treated also carries the risk of death. So the small risk of diseases (which cannot be tested for) being present and maybe causing illness in a few years time is outweighed by the extreme unlikeliness of making through those few years without the transplant.

Whereas with blood; matching is needed but, even with the rare blood groups, there are thousands of suitable donors

I was able to donate in the USA when I was a student there in 1998 but then when I tried again in 2005 (when I was back again living there for work) was told no due to simply having lived in the UK for a period of time! They consider the vCJD risk to be so high!

I had a blood transfusion after DD was born but that wasn't in the UK. Does that mean that I could give blood in the UK now?

Yes, although, having said all that, my understanding is that the latest evidence is suggesting that vCJD might turn out to be a lot less common than once feared, and it's been getting on to three decades since the BSE crisis, so it might be possible to drop the restriction before too much longer.

Looks like cases peaked in 2000, and since dropped to essentially nothing, so the risk of anyone incubating variant CJD and passing it on via blood donation are vanishingly unlikely. I think that this rule, while a sensible precaution when it was introduced, can probably now be safely dropped.