Viral Safety of clotting factor concentrates
In the late 1970s, people with haemophilia were treated with clotting factor concentrates pooled from the plasma of multiple donors. Many individuals who received these concentrates were infected with viruses that had been undetected in the donated blood. The first group of viruses identified were the hepatitis viruses A, B and C.
During the late 1970s and 1980s, HIV contaminated many clotting factor concentrates, resulting in thousands of deaths from AIDS. This terrible tragedy led to not only the way donated blood was screened, but also radical changes in the way clotting factor concentrates were manufactured; this vastly improved their safety and reduced the risk of viral contamination. Today’s clotting factor concentrates undergo rigorous screening and decontamination processes that include heating, filtering, and the use of solvents and detergents to remove or inactivate any potential impurities.
Despite the use of modern and very strict manufacturing techniques in the production of clotting factor concentrates, which have virtually eliminated the risk of hepatitis and HIV infection, there is still a small risk of infection from a virus called the parvovirus (which can cause anaemia) and from prions (which cause the human form of mad cow disease). Manufacturers of clotting factor concentrates are working hard to find ways of overcoming these risks.