Screening Reduces Risk of Transfusion-Transmitted Babesiosis

HealthDay News — Screening for Babesia microti antibodies and DNA in blood-donation samples is associated with a reduction in the risk of transfusion-transmitted babesiosis, according to a study published in the New England Journal of Medicine.

Erin D. Moritz, PhD, from the American Red Cross in Gaithersburg, Maryland, and colleagues performed arrayed fluorescence immunoassays (AFIAs) for B microti antibodies and real-time polymerase-chain-reaction (PCR) assays for B microti DNA on blood-donation samples from Connecticut, Massachusetts, Minnesota, and Wisconsin. Data on cases of transfusion-transmitted babesiosis were used to compare the proportions of screened vs unscreened donations that were infectious.

The researchers found that 0.38% (335 samples) of the 89,153 blood-donation samples tested were confirmed to be positive. Of these, 20% were PCR-positive; 9 samples were antibody-negative, representing 13% of all PCR-positive samples. There were no reported cases of transfusion-transmitted babesiosis in association with screened donations in Connecticut and Massachusetts while there were 14 cases per 253,031 unscreened donations (odds ratio, 8.6; P =.05). Twenty-nine cases of transfusion-transmitted babesiosis were associated with infected donor blood.

“Blood-donation screening for antibodies to and DNA from B microti was associated with a decrease in the risk of transfusion-transmitted babesiosis,” the authors write.

The study was funded by the American Red Cross and Imugen.

Reference

Moritz ED, Winton CS, Tonnetti L, et al. Screening for Babesia microti in the U.S. blood supply. N Engl J Med. 2016;375:2236-2245. doi: 10.1056/NEJMoa1600897