title: Babesia: impact of cold storage on the survival and the viability of parasites in blood bags.
abstract: BACKGROUND
  Babesia represents one of the major infectious threats to the blood supply since clinically silent infections in humans are common and these can be life-threatening in certain recipients. It is important to understand the effect of blood storage conditions on the viability of Babesia as this will impact the occurrence and severity of transfusion-transmitted babesiosis.
  
  
  METHODS
  Babesia divergens was introduced into blood bags containing leukoreduced red blood cells (RBCs) and stored at 4°C for 0 to 31 days. Samples were withdrawn for assessment of the presence, morphology, and viability of parasites. Blood smears were made immediately on removal from blood bags at different time intervals and evaluated by blood film microscopy. RBCs withdrawn from the bags were also cultured for 8 days using conditions optimal for parasite reproduction and growth to allow assessment of parasite viability.
  
  
  RESULTS
  After 24 hours of storage at 4°C, there was a substantial reduction of parasitemia in the blood bags, which was maintained throughout storage. This decrease was accompanied by a change in morphology of parasites, with the number of altered parasites increasing through the period of storage. However, viability was maintained through 31 days of cold storage with a lag in achieving exponential growth seen in the parasites subjected to longer periods of refrigeration.
  
  
  CONCLUSIONS
  Refrigeration of B. divergens leads to an alteration of parasite morphology and a decrease in parasite numbers. However, there are sufficient parasites that are robust enough to survive 31 days of storage at 4°C and yield high end-point parasitemia.
authors.affiliation: Department of Blood-Borne Parasites, Lindsley Kimball Research Institute, New York Blood Center, New York, New York.
authors.forename: Jeny R
authors.initials: JR
authors.lastname: Cursino-Santos
authors.forename: Andy
authors.initials: A
authors.lastname: Alhassan
authors.forename: Manpreet
authors.initials: M
authors.lastname: Singh
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Lobo
mesh_terms: D001403:Babesia / Q000302:isolation & purification*; D016913:Blood Component Transfusion; D001793:Blood Preservation / Q000592:standards*; D003080:Cold Temperature; D015925:Cryopreservation / Q000592:standards*; D004912:Erythrocytes / Q000469:parasitology*