A number of parasitic diseases have been reported to be 
transmitted by blood transfusion, including malaria, 
leishmaniasis, Chagas' disease, babesiosis, toxoplasmosis 
and filariasis. Majority of blood banks do not screen donor 
blood samples for these potentially pathogenic parasites, this 
poses great risk to the recipients of blood, especially 
immunocompromised patients and those who need regular, 
frequent and multiple transfusions. Transfusion-transmitted 
parasitic infections depend on several factors; asymptomatic 
parasitemia individual qualifies as a blood donor, the ability 
of the parasite to survive on stored donated blood, and the 
infected blood is transfused in a sufficient dose to a 
susceptible patient.