Transmission of Parasites by Blood Transfusion

A number of parasitic diseases are known, or suspected to be transmitted by blood transfusion. Of greatest concern are malaria and Chagas' disease, but babesia, leishmania and toxoplasmosis also offer risk in particular locations or circumstances. Some of these parasites may be imported into non-endemic areas as a result of population movements and in some cases, the natural range of the parasite is increasing as a result of environmental change. Recent research, particularly on Chagas disease and babesiosis will be discussed, along with measures to minimize transmission of these and other parasites via transfusion.     

Estimated Risk of Transmission of Hepatitis C Virus by Blood Transfusion

Objective : The risk of transmitting hepatitis C (HCV) by transfusion of anti-HCV-negative screened blood was estimated for the blood donor population of Baden-Württemberg (southwestern Germany). Methods : The data from the blood donors screened for anti-HCV and for HBsAg during 1990-1995 were analyzed. Results : The prevalence of confirmed anti-HCV-positive blood donations decreased continuously during the last 5 years, reaching 121 per 100,000 blood donations. A higher anti-HCV prevalence rate was found in female than in male blood donors (p<0.05). The estimated risk of transmitting HCV during the window period is 1:200,000 (1:97,000–1:1,400,000) for repeat donors. In 1995, the calculated risk for first-time donors was 1:20,000 (1:15,000–28,000). The incidence for HCV was 1.2 per 100,000 blood donations. Conclusion : The risk of transmitting hepatitis C by blood transfusion is low. Additional tests to shorten the window period to detect antibodies to HCV might increase the safety of blood transfusion.     

Transmission of Hepatitis C Virus by Anti-HCV-Negative Blood Transfusion: Case Report

Acute posttransfusion hepatitis C was reported in a recipient of 3 units of red cells. The recipient became acutely icteric 6 weeks after transfusion, and HCV infection was diagnosed. Stored serum samples of the 3 implicated donations, which were negative with ELISA-2, were retested by PCR and 3rd-generation antibody tests. One implicated donation was PCR positive, but anti-HCV negative. Both other donations were negative in all tests. The donor was recalled to the Blood Bank 13 weeks after the implicated donation and was found to be ELISA-3 plus RIBA-3 positive. Eight months after the implicated donation, the donor is still PCR and RIBA-3 positive, whereas the recipient became PCR negative but remained anti-HCV RIBA-3 positive. The case shows that blood products from donors collected during the open window period of an HCV infection can transmit HCV to recipients.     

The Incidence and Consequences of Cytomegalovirus Transmission via Blood Transfusion to Low Birth Weight, Premature Infants in North East Scotland

In a 2-year study involving 133 premature low birth weight (less than 1,500 g) infants, the impact of CMV infection via blood transfusion was assessed. 8.4% (7 out of 83) of transfused infants and 10% (7 out of 70) of those exposed to seropositive blood acquired CMV. In those less than 1,250 g the infection rate rose to 13.2% (7 out of 46). Seropositive infants were at a higher risk of acquiring CMV infection than seronegative ones. CMV infection did not give rise to specific immediate morbidity, and no deaths were attributed to CMV. The only source of nosocomial CMV infection was the transfused seropositive blood. Based on these findings, it was possible to formulate a CMV transfusion policy to premature infants in our region.     

Blood Transfusion or Blood Substitution?

Blood transfusion has become a universally accepted, life-saving procedure in modern clinical medicine. In addition, specific blood fractions are widely used in the therapeutic treatment of haematological disorders. Problems are, however, encountered in conventional transfusion practice and in the clinical use of blood components. This paper outlines some of those problems and considers how plasma expanders and oxygen-carrying blood substitutes may be used to overcome some of them. The extent to which acceptable blood substitutes have been developed and tested in both animal and human studies is especially emphasized.     

International Society of Blood Transfusion

Book reviewed in this article:
B. Cinader (ed.) Immunology of Receptors
A. E. Mourant A. C. Kopeć K. Domaniewska-Sobczak The Genetics of the Jews
A. E. Mourant, A. C. Kopeć, K. Domaniewska-Sobczak Blood Groups and Diseases