In 2015, the Zika virus (ZIKV) rapidly spread to the Americas and other countries, and four possible transfusion-transmission cases were documented in Brazil. In 2016, the US Food and Drug Administration (FDA) recommended ZIKV screening for all blood donations within the continental United States. The American Red Cross reports in The New England Journal of Medicine on the screening of 4,325,889 samples collected from June 2016 to September 2017. No ZIKV positive samples were found in the 9% (393,713) of the samples that were screened in minipools. Of the 3,932,176 samples screened individually, 9 were confirmed to be ZIKV positive (1: 480,654). ZIKV RNA levels ranged from 40 to 800,000 copies per milliliter in red cells. The cost of identifying each ZIKV RNA positive donor was $5.3 million, and it is unclear whether these samples were infectious or not. Further discussion and research is warranted in order to determine if ZIKV RNA positive blood samples are infectious and if all donated blood samples should be screened for ZIKV.
References:
- Saa P, Proctor M, Foster G, Krysztof D, et al. Investigational testing for Zika virus among U.S. blood donors. New England Journal of Medicine 2018; 378; 1778-1788.
- Bloch EM, Ness PM, Tobian AAR, and J Sugarman. Revisiting blood safety practices given emerging data about Zika virus. New England Journal of Medicine 2018; 378; 1837-1841.
