In the 1970s and 1980s, a large number of people – most of whom had haemophilia – were infected with hepatitis C and HIV, the virus that leads to acquired immune deficiency syndrome (AIDS), as a result of receiving contaminated clotting factor products. In the United Kingdom, these were supplied by the National Health Service (NHS). The Haemophilia Society estimates that around 4,700 people with bleeding disorders were infected, with some estimates as high as 6,000. As of August 2022, at least 2,400 people have died from the use of contaminated factor VIII and factor IX clotting agents and the viruses they transmitted.