Rate of infection from HIVinfected transfusions

Not all recipients of HIV–infected blood seroconvert. A 1989 study of 220 recipients of blood from HIV–positive donors found that 85 were HIV–negative. Those who seroconverted were more likely to have received large quantities of blood and/or to have received blood from a donor who subsequently developed AIDS less than two and half years after giving blood.

Those who progressed to AIDS within seven years of the transfusion were more likely to have received large quantities of blood when transfused, and to have been more severely ill (measured by length of stay in hospital). After seven years 49% of the recipients of infected blood were estimated to have progressed to AIDS. Those who had received blood from donors who developed AIDS within two and half years of giving blood were more likely to have developed AIDS within four years than those who didn't (Ward).

Transfusing your own blood

In order to protect themselves against HIV infection, some people choose to have their own blood used in transfusions, a practice known as an autologous transfusion. This practice is becoming increasingly common in the United States and some European countries, and patients often say that it makes them worry less about the chance of HIV infection.

In fact, autologous transfusions are more important as a source of protection against other more common infections transmitted by transfusions which cause post–operative complications, such as CMV. Such transfusions also reduce the stress placed on the immune system by a transfusion of foreign proteins, so they may benefit people with HIV too. An infusion of foreign blood proteins can activate the immune system and boost HIV replication and infection of new cells. Unfortunately blood may not always be suitable for autologous transfusion; some people may be too weak or anaemic to benefit from autologous transfusions.

Blood transfusions abroad

In certain other countries infection through blood transfusion is a much higher risk.

The most up–to–date and reliable information about the risks of blood transfusion abroad is likely to be available from:

• MASTA at the London School of Hygiene and Tropical Medicine (0891–224100)
• The Foreign and Commonwealth Office Consular Department's Travel Office (020 7270 3000)
• If you are employed abroad, from your employer.

The UK NGO AIDS Consortium has published a manual for employment by voluntary organisations working abroad which includes material for employees.

References

Ward JW: The natural history of transfusion–associated infection with human immunodeficiency virus: factors influencing the rate of progression to disease, NEJM 321(14): 947–952, 1989.

Awareness of people with clotting or bleeding conditions (i.e. Haemophilia) has existed for 2,000 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 Willibrand'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 produced by 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. Many people with haemophilia have been disabled for some time and, even before the advent of HIV, 35% were receiving state benefits.

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 these transfusions were often contaminated with the hepatitis B and hepatitis C viruses. By the late 1970s 100% of people with Haemophilia treated with pooled Factor VIII had come into contact with these viruses. The problem was blamed on imported Factor VIII and in 1977 the British government pledged to become independent in blood supplies.