Awareness of people with clotting or bleeding conditions (i.e. haemophilia) has existed for 2000 years. It was not, however, until the early part of this century, that bleeding disorders were classified as haemophilia A or B (Christmas Disease) and Von Willebrand's disease (VW). VW can affect either men or women. Haemophilia A and B affect only men, although women carry the haemophilia gene, which will affect half their male offspring.
All three conditions are the result of an inability to produce a protein which causes blood to clot after an injury. The condition has varying degrees of severity. Some people with haemophilia only bleed after a severe injury, but some people will bleed very easily, even after a minor knock and many of these bleeds are internal. Bleeds in joints are particularly disabling as eventually the joints will seize up, causing severe arthritis.
In the 1970s doctors started replacing the deficient protein (Factor VIII in haemophilia A and VW, and Factor IX in haemophilia B) with blood products or factor concentrates. Such small quantities of protein are present in blood that donations from up to 30,000 people had to be pooled to produce one batch. The results of infusion with concentrates were excellent, and by the mid 1970s people with haemophilia were injecting themselves with Factor VIII at home with the onset of a bleed.
However, as a result of relying upon such a huge donor pool, blood products have always been susceptible to contamination by viruses. All people with haemophilia treated with factor concentrates during the 1970s and early 1980s were exposed to infection with the hepatitis viruses B and C.
Moreover, despite the fact it was known that a person with haemophilia died in the United States in 1981 from what is now termed an AIDS-related illness, the association between factor concentrates, AIDS and viral contamination was not made until 1983. In early 1984 in Britain there were at least two reported cases of AIDS in people with haemophilia and later that year, after months of prevarication by the pharmaceutical companies and authorities over whether to heat-treat factor concentrates or not, the Haemophilia Foundation in the USA instructed the 20,000 people with haemophilia in the United States to refuse to use all non-heat-treated product. The UK Haemophilia Society threatened to follow suit. By the end of 1984, all imported commercial concentrate in the UK was heat-treated. By mid-1985, domestic product was also treated to destroy the virus. Earlier there had been an attempt to encourage donors who may have been at risk of exposure to AIDS, such as people who had lived in sub-Saharan Africa, gay men and intravenous drug users, not to give blood.
When the test for HIV was pioneered, people with haemophilia were routinely tested. The enormity of the disaster became clear. In the United States, around 10,000 of the 20,000 people with haemophilia were diagnosed as seropositive. In the United Kingdom, of the 7000 people with haemophilia 1246 were infected, representing 42% of those with severe haemophilia and 6% of those with moderate or mild haemophilia.1 As a general rule, people were infected in proportion to the amount of commercial concentrate used: the more severe the haemophilia, the more concentrate used, the higher the risk of infection.
Once blood products were heat-treated, the haemophilia community effectively ceased to be at risk of HIV infection from their treatment. Those with haemophilia and HIV are therefore a finite group of people. After mid-1985, at the very latest, no person should have been infected with HIV in the UK through the use of factor concentrates. Naturally people with haemophilia remain as much at risk of contracting HIV sexually or through sharing needles as everyone else.