The researchers have used databases of blood transfusions and data on infections from the Swedish Public Health Agency's system Sminet. These are 1,180 living people who probably contracted blood between 1960 and 1990.

Researcher Gustaf Edgren at Karolinska Institutet believes that among these, hundreds of people who carry the infection can be identified. However, not all 1,180 people need to carry hepatitis C - for example, the blood donor may have been infected with hepatitis C only after the blood donation, so that the blood received was never infected.

Right to treatment and compensation

The people who have been identified must now be contacted by infection control doctors in the regions and offered testing within the framework of a research study. If it turns out that they have received hepatitis C via blood transfusion, they are entitled to treatment and compensation for medical damage.

- We can not say with certainty how many of these are infected. But we think we have enough justification for contacting and offering them sampling, says Gustaf Edgren to Dagens Medicin.

Swedish blood donors routinely began testing for hepatitis C in 1990 when the virus was discovered.