“Physicians should consider babesiosis in the differential diagnosis in immunocompromised, febrile patients with a history of recent transfusion,” the research team, led by Dr. Diane M. Gubernot at the FDA in Rockville, Maryland, advises in the January 1 issue of Clinical Infectious Diseases.
The protozoal zoonotic illness is transmission by ticks, primarily Ixodes scapularis, in North America. The infection can be asymptomatic or fatal. Most cases are caused by Babesia duncani.
Even though babesiosis is not nationally notifiable, they urge clinicians to report all babesiosis-related donor and transfusion events to public health authorities and transfusion facilities so that appropriate and timely public health-control measures can be implemented.
Dr. Gubernot’s team queried FDA safety surveillance systems for trends in babesiosis reporting since 1997. Nine of 10 deaths occurred between 2005 and 2008. Patient ages ranged from 43 to 88 years.
Most of the patients developed altered mental status, renal failure, or respiratory distress, with symptom onset 2.5 to 7 weeks following transfusion. Once symptoms developed, death followed within 5 to 17 days. Implicated donations were identified, and all donors tested positive by peripheral blood smear or immunofluorescence antibody assay.
“Infectious disease consultation may be required to microscopically distinguish Babesia species from Plasmodium organisms,” the authors note.
In addition to the fatal cases, the number of reports to the Biological Product Deviations Reporting system of potential transfusion-transmitted Babesia infection and postdonation babesiosis ranged from zero in fiscal year 1999 to 25 in fiscal year 2007.
The researchers note that Babesia species can survive blood banking procedures, including freezing, and can be transmitted through transfusion of RBCs, deglycerolized RBCs, and platelets.
Clin Infect Dis 2009;48:25-30.