In February, the FDA initiated the first of what it says will be a series of actions that address the evolving risks surrounding the Zika virus, taking steps to slow its growth within the United States and throughout the world.
The first step the agency took had to do with the nation’s blood supply, issuing guidance for blood donation centers to prevent people from donating blood if they present risk factors. Centers are to add screening criteria to determine if donors have been to areas with active Zika virus transmission, potentially have been exposed to the virus, or have had a confirmed Zika virus infection.
“The FDA has critical responsibilities in outbreak situations and has been working rapidly to take important steps to respond to the emerging Zika virus outbreak,” said Luciana Borio, M.D., the FDA’s acting chief scientist. “We are issuing this guidance for immediate implementation in order to better protect the U.S. blood supply.”
Thus far, there have been no reports of the virus entering the U.S. blood supply, but the FDA believes that the risk of blood transmission is possible, even likely, based on “scientific evidence of how Zika virus and similar viruses (flaviviruses) are spread and recent reports of transfusion-associated infection outside the U.S.” Also, 4 out 5 people with the virus show no symptoms, making additional precautions necessary.
Specifically, the guidelines say, “In areas without active Zika virus transmission, the FDA recommends that donors at risk for Zika virus infection be deferred for four weeks.” People are considered at risk if they report any symptoms suggestive of Zika virus infection during the prior four weeks, if they have had sexual contact with a person who has been in an area with active Zika virus transmission during the prior three months, and if they have traveled to areas with active transmission of Zika virus during the prior four weeks.
Where there is active virus transmission, “the FDA recommends that Whole Blood and blood components for transfusion be obtained from areas of the U.S. without active transmission.” Plasma and platelets can still be obtained, but only when using FDA-approved pathogen testing equipment and procedures.
In March, the FDA expanded its recommendations to include the use of human cells, tissue, and cellular and tissue-based products (HCT/Ps). It recommends that donors of these biological products be considered ineligible if they were diagnosed with the Zika virus, were in an area with active Zika virus transmission, or had sex with a male with either of those risk factors within the past six months.
“Though there is more to be learned about the transmission of Zika virus, given what we know about the virus at this point, which also is informed by our understanding of similar viruses, we must address the potential risk of Zika virus transmission by human cells and tissues,” said Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research. “Providing HCT/P establishments with donor eligibility recommendations will help reduce that potential risk.”
According to the agency, “Donors should be considered ineligible if they were diagnosed with Zika virus infection, were in an area with active Zika virus transmission, or had sex with a male with either of those risk factors, within the past six months. Donors of umbilical cord blood, placenta, or other gestational tissues should be considered ineligible if they have had any of the above risk factors at any point during their pregnancy.”
For organ donations from deceased individuals, “Donors should be considered ineligible if they were diagnosed with Zika virus infection in the past six months.”