Treatment of haemophilia
Since the 1970s, doctors have successfully treated people with haemophilia by injecting them with clotting factors which can be purified from donated blood. Unfortunately, many people have been infected with viruses after receiving clotting factors made from infected blood. In the UK, 1220 people were infected with HIV in this way. Doctors now test and heat-treat donated blood to ensure its safety. In the future, haemophilia may be treated using clotting factors produced by genetically engineered bacteria.