350. Ticks Are Not the Only Vector: Platelet Transfusion-transmitted Anaplasmosis
Session: Poster Abstract Session: HAI: Outbreaks
Thursday, October 8, 2015
Room: Poster Hall
Background: Human granulocytic anaplasmosis (HGA) is an emerging tick-borne illness caused by the obligate intracellular bacterium, Anaplasma phagocytophilum. While babesiosis is well-recognized as a tick-borne infection transmissible by blood products, only eight cases of transfusion-transmitted anaplasmosis (TTA) have been reported to date: seven attributed to red blood cell (RBC) units, five of which were pre-storage leukoreduced using red cell leukoreduction filters, and one involving a process leukoreduced apheresis platelet (PLT) unit. Here we describe the first confirmed case of TTA from a whole blood derived platelet pool that was leukoreduced by filtration. CASE PATIENT: A 78-year-old female underwent coronary artery bypass surgery following a cardiac arrest. A total of seven RBC units and two PLT units were transfused. Ten days later, the patient was readmitted with fever and hypoxia. Laboratory abnormalities included a hemoglobin of 6.8 g/L, WBC of 2.4 x 109/L, platelets of 93 x 109/L, creatinine of 8.48 mg/dL, and AST of 101 IU/L (N: 10-42). A peripheral smear revealed morulae. Treatment with Doxycycline was initiated with symptom resolution and normalization of laboratory abnormalities. 

Methods: Donation segments from the RBC and PLT units were examined. Fast protocol multiplex real-time polymerase chain reaction (PCR) to detect the presence of A.phagocytophilum DNA and serologic testing for IgM and IgG antibodies to A.phagocytophilumby Enzyme Immunoassay (EIA) were performed.

Results: Of the 16 donors, one whole blood donor who contributed to the platelet pool tested positive by PCR and serology with an IgM titer of 3.5 and an IgG titer of 5.1 (N: <1.0 for each titer). The recipient tested positive for A.phagocytophilumPCR and seroconverted two weeks after symptom onset.

Conclusion: This is the first confirmed case of TTA from a whole blood derived platelet pool leukoreduced by filtration. An acute febrile illness in a recent recipient of blood products should prompt the consideration of TTA, even in non-endemic areas, as shipment of blood products and recreational travel of blood donors may widen the geographic distribution of this disease. Further research to address cost effectiveness of screening and pathogen reduction methods is needed.

Antonella B. Fine, MD and Bettina M. Knoll, MD, PhD, Division of Infectious Diseases, Warren Alpert Medical School of Brown University, Providence, RI


A. B. Fine, None

B. M. Knoll, None

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