This work was supported in part by the Centers for Disease Control and Prevention (Cooperative Agreement UR9/CCU316878) and by the American Red Cross Biomedical Services.
DONOR INFECTIOUS DISEASE TESTING
A longitudinal study of Babesia microti infection in seropositive blood donors
Article first published online: 28 MAR 2014
© 2014 AABB
Volume 54, Issue 9, pages 2217–2225, September 2014
How to Cite
Leiby, D. A., Johnson, S. T., Won, K. Y., Nace, E. K., Slemenda, S. B., Pieniazek, N. J., Cable, R. G. and Herwaldt, B. L. (2014), A longitudinal study of Babesia microti infection in seropositive blood donors. Transfusion, 54: 2217–2225. doi: 10.1111/trf.12622
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.
- Issue published online: 11 SEP 2014
- Article first published online: 28 MAR 2014
- Manuscript Accepted: 17 JAN 2014
- Manuscript Revised: 3 JAN 2014
- Manuscript Received: 9 SEP 2013
- Centers for Disease Control and Prevention. Grant Number: UR9/CCU316878
- American Red Cross Biomedical Services
Babesia infection is caused by intraerythrocytic tick-borne parasites. Cases of transfusion-transmitted babesiosis have been increasingly recognized. To date, no Babesia test has been licensed for screening US blood donors. We conducted a longitudinal study to assess the course and markers of Babesia infection among seropositive donors identified in a seroprevalence study.
Study Design and Methods
Eligible donors had B. microti indirect fluorescent antibody (IFA) titers of 64 or greater. Enrollees were monitored up to 3 years, by IFA and three methods for evidence of parasitemia: B. microti nested polymerase chain reaction (PCR) analysis (at two laboratories), hamster inoculation, and blood-smear examination.
Among 115 eligible donors, 84 (73%) enrolled. Eighteen enrollees (21%) had evidence of parasitemia for 30 total specimens (17% of 181), which were collected in 9 different months and tested positive by various approaches: PCR (25 specimens/16 persons), hamster inoculation (13 specimens/8 persons), and blood smear (one specimen positive by all three approaches). Overall, 14 persons had one or more specimen with positive PCR results at both laboratories (12 persons) and/or had parasitologically confirmed infection (eight persons). Three of nine persons who had more than one specimen with evidence of parasitemia had nonconsecutive positives. Several enrollees likely had been infected at least 1 year when their last positive specimen was collected. The final three specimens for seven persons tested negative by all study methods, including IFA.
Seropositive blood donors can have protracted low-level parasitemia that is variably and intermittently detected by parasitologic and molecular methods. Donor-screening algorithms should include serologic testing and not solely rely on molecular testing.