Transfusion–Transmitted Parasites

Extract

The incidence of transfusion-transmitted parasitic infections is even lower when compared to that of bacterial and viral contamination; but nonetheless, these organisms may pose a significant risk of illness, especially in immunocompromised recipients. Unlike bacterial contamination, which can occur at multiple points during the collection and transfusion process, transfusion-transmitted parasitic diseases originate from the donor. The most common parasitic organisms implicated in transfusion-transmitted infections are: Plasmodium sp., the causative agent of malaria; Trypanosoma cruzi, the agent responsible for Chagas' disease; and Babesia microti, the etiologic agent of babesiosis. These organisms are gaining prominence due to global travel and increased exposure to habitats where insect vectors reside. Population migration from endemic countries to the U.S. also contributes to the recent increases in parasite transmission.¹ In this article we will discuss the organisms and their prevalence as well as detection methods as they relate to transfusion transmission.

Despite the fact that organisms such as Ehrlichia are bacteria, they will be discussed in this section because they are obligate intracellular organisms that can be transmitted via cells present in a transfusion. They are not normal flora or environmental contaminants – they are primarily insect-transmitted, as are the parasites discussed. These organisms, which have the potential to be transfusion-transmitted, but have limited evidence documenting transmission via blood components, merit discussion.