Most if not all surgical procedures involve risks to a patient, however the transfusion of one person's venous blood into another individual, presents various risks which the National Health Service in the U.K. acknowledge and address via their website for health professionals, SERIOUS HAZARDS of TRANSFUSION. (S.H.O.T.)
http://www.shotuk.org/
Very interesting site with a very interesting report.
http://www.shotuk.org/wp-content/uploads/SHOT-2015-Annual-Report-Web-Edition-Final-bookmarked.pdf
Basically there were 26 deaths that had at best a possible cause of death related to a blood transfusion. That is across the UK in a year with 2.5 million instances of blood being issued.
The report is very detailed and shows that many of these issues and reported errors were due to human error not a biological issue with the blood or procedure.
Of course this is a very simplistic cherry pick of some figures but no worse than the highly selective and biased reporting the WT does. They leverage the ignorance of people to induce fear whilst watering down their own doctrine with illogical positions on how blood should be treated.
The blood doctrine and it's disingenuous, hypocritical application by the WTS disgusts me. They pressurise people into compliance with a potentially life threatening doctrine yet do not have the moral integrity to even be consistent in how they approach the subject.
The blood of many innocents is on the hands of each the GB members who have consistently pushed this hypocrisy forward and it saddens me that so few will ever awake to this realisation.