Safety of blood and blood products in Scandinavia today.

Abstract

The safety of blood and blood products in Scandinavia today is high. An absolutely safe blood supply is, however, an unattainable goal. The dominating risk is transmission of non-A, non-B virus (NANBV). The calculated per blood unit risk is 1:200. The incidence of cirrhosis due to post-transfusion hepatitis NANB is calculated to at most 0.1% among recipients of blood components from about 5 donors. Other risk factors are transmission of hepatitis B virus (HBV), human immunodeficiency virus (HIV-1) and cytomegalovirus (CMV). The prevalence of HBsAg among first time donors is about 0.05% (Sweden). In Scandinavia, anti-HIV-1 has been found in 0.001% of donations from start of screening in 1985 to December 1987. The prevalence was higher in Denmark, lower in Finland (and perhaps Iceland). The prevalence has declined during the last years. As of June 1988, 117 patients in the Scandinavian countries have been infected by blood components, all but 2 before screening was introduced. Besides these, 226 haemophiliacs have been infected by, in almost all cases, imported clotting factor concentrates before heat treatment was introduced. Most of the infected patients are still asymptomatic. About 70% of blood donors have anti-CMV, a few percent of which will transmit CMV-infection, with severe symptoms, to immunosuppressed patients without anti-CMV.