Transfusion-associated malaria has a shoer incubation period because of the presence in blood of:

Ans: A. Trophozoites(Ref: Paniker's 7/e p77, 6/e p69; Harrison 19/e p1374)Transfusion associated malaria has a shoer incubation period because of presence of trophozoites in blood.Malaria can be transmitted by blood transfusion, needle-stick injury, sharing of needles by infected injection drug users, or organ transplantation.The incubation period in these settings is often sho because there is no pre-erythrocytic stage of development.Parasites may remain ble in blood bank for 1-2 weeks.As this condition is induced by direct infection of red cells by the merozoites, pre-erythrocytic schizogony and hypnozoits are absent.Relapse does not occur and incubation period is sho.