tailieunhanh - Chapter 107. Transfusion Biology and Therapy (Part 9)

Other Hepatitis Viruses Hepatitis A virus is rarely transmitted by transfusion; infection is typically asymptomatic and does not lead to chronic disease. Other transfusion-transmitted viruses—TTV, SEN-V, and GBV-C—do not cause chronic hepatitis or other disease states. Routine testing does not appear to be warranted. West Nile Virus Transfusion-transmitted WNV infections were documented in 2002. This RNA virus can be detected using NAT; routine screening began in 2003, and more than 1000 blood donors have tested positive. WNV infections range in severity from asymptomatic to fatal, with the older population at greater risk. Cytomegalovirus This ubiquitous virus infects ≥50% of the general population and. | Chapter 107. Transfusion Biology and Therapy Part 9 Other Hepatitis Viruses Hepatitis A virus is rarely transmitted by transfusion infection is typically asymptomatic and does not lead to chronic disease. Other transfusion-transmitted viruses TTV SEN-V and GBV-C do not cause chronic hepatitis or other disease states. Routine testing does not appear to be warranted. West Nile Virus Transfusion-transmitted WNV infections were documented in 2002. This RNA virus can be detected using NAT routine screening began in 2003 and more than 1000 blood donors have tested positive. WNV infections range in severity from asymptomatic to fatal with the older population at greater risk. Cytomegalovirus This ubiquitous virus infects 50 of the general population and is transmitted by the infected passenger WBCs found in transfused PRBCs or platelet components. Cellular components that are leukocyte-reduced have a decreased risk of transmitting CMV regardless of the serologic status of the donor. Groups at risk for CMV infections include immunosuppressed patients CMV-seronegative transplant recipients and neonates these patients should receive leukocyte-depleted components or CMV seronegative products. Human T Lymphotropic Virus HTLV Type I Assays to detect HTLV-I and -II are used to screen all donated blood. HTLV-I is associated with adult T cell leukemia lymphoma and tropical spastic paraparesis in a small percentage of infected persons Chap. 181 . The risk of HTLV-I infection via transfusion is 1 in 641 000 transfusion episodes. HTLV-II is not clearly associated with any disease. Parvovirus B-19 Blood components and pooled plasma products can transmit this virus the etiologic agent of erythema infectiosum or fifth disease in children. Parvovirus B-19 shows tropism for erythroid precursors and inhibits both erythrocyte production and maturation. Pure red cell aplasia presenting either as acute aplastic crisis or chronic anemia with shortened RBC survival may occur in individuals with