EN
Transfusions of blood or blood products are commonly used in medicine, but being biological materials they carry a risk of transmitting infections ? viral, bacterial, parasitic, as well as prions. Laboratory tests used for screening of donated blood for viral infections at present cannot detect all infectious units. Criteria for selection of blood donors therefore must be very strict, while methods of inactivation of viruses and laboratury assys for detection of their presence must be improved. Indications for blood transfusion should be restricted.