Transfusion-transmitted anaplasmosis from a leukoreduced platelet pool

Area of Science:

• Transfusion Medicine
• Infectious Diseases
• Tick-borne Illnesses

Background:

• Human granulocytic anaplasmosis, caused by Anaplasma phagocytophilum, is an emerging tick-borne disease.
• Anaplasma phagocytophilum can survive refrigeration in blood components for extended periods.
• Previous cases of transfusion-transmitted anaplasmosis (TTA) involved red blood cells (RBCs) and one apheresis platelet (PLT) unit.

Observation:

• A case of TTA was reported from a whole blood-derived PLT pool.
• Donation segments from transfused RBC units and PLT pools were analyzed.
• Multiplex real-time PCR and serologic testing were performed on donors and recipients.

Findings:

• Transmission of Anaplasma phagocytophilum was confirmed in the recipient.
• Positive PCR and seroconversion were observed in the recipient.
• One of 16 donors tested positive for Anaplasma phagocytophilum via PCR and serology.

Implications:

• This is the first confirmed case of TTA from a whole blood-derived PLT pool.
• It demonstrates the potential for Anaplasma phagocytophilum transmission via leukoreduced PLT concentrates.
• Highlights the need for vigilance regarding TTA in transfusion medicine.