SURVIVAL AND INFECTIVITY OF BABESIA IN BLOOD MAINTAINED AT 25 C AND 2-4 C

Babesia microti-infected blood was stored at room temperature (similar to 25 C) or refrigerated (4 C) for 30 days. To assess viability of th e parasites after storage at these 2 temperatures, a 0.25-ml aliquot w as inoculated into each of 2 hamsters in 2 separate experiments at day s 3, 7, 10, 14, 17, 21, 25, and 30. Blood films were prepared and exam ined weekly for the presence of parasites from all hamsters. Of hamste rs inoculated with blood held at room temperature, only those inoculat ed at day 3 became positive, whereas 4/4 hamsters inoculated with refr igerated blood on day 17 became parasitemic and 1/4 hamsters inoculate d with blood held for 21 days became parasitemic. These results indica te that under blood banking conditions, this intracellular protozoan p arasite can remain infective and transfusion-acquired infection with t his parasite could occur throughout most of the time that blood is nor mally stored.