Which of the following parasites causes transfusion-associated infections?

In the context of transfusion-associated infections, Plasmodium malariae is particularly relevant because it is one of the species of the Plasmodium genus responsible for malaria, a disease that can be transmitted through contaminated blood products. Malaria can cause severe illness, and transmission can occur even when blood is asymptomatic, making it a significant concern for blood transfusion safety.

While all the parasites listed can be associated with various health issues, Plasmodium malariae stands out in transfusion contexts due to its ability to infect humans through blood and can lead to malaria transmission in recipients.

Babesia microti is also a transfusion-related parasite associated with transfusion-transmitted infections and can cause similar symptoms to malaria, but Plasmodium malariae historically represents a more widely recognized concern in transfusion medicine. Leishmania donovani and Toxoplasma gondii have routes of transmission that are less commonly associated with blood transfusions, focusing instead on other modes of transmission such as vector-borne or congenital routes.

Understanding the implications of these parasites in the setting of transfusion medicine is critical for ensuring patient safety and preventing infectious complications associated with blood transfusion practices.