The Food and Drug Administration on Friday took steps to safeguard the nation's blood supply from the Zika virus, calling for all blood banks to screen donations for the infection even if they are in states where the virus is not circulating.
The agency urged blood centers to use one of two experimental tests intended to detect active infections, called nucleic acid tests, before releasing donated blood for use in transfusions. As an alternative, banks may decontaminate plasma and platelets with so-called pathogen reduction technology.
The recommendations are an acknowledgment that sexual transmission may facilitate Zika's spread even in areas where mosquitoes carrying the virus are not present. Officials also worry clusters of local infection may continue to pop up in parts of the United States for years to come. Both factors pose risks to the supply of donated blood.
Because of their increased risk for contamination, 11 states must put the new safeguards into place as soon as possible, but no later than four weeks from today. They include Texas, Alabama, Arizona, California, New York and Louisiana. Other states without active Zika transmission, such as Massachusetts and New Mexico, have 12 weeks to carry out the recommendations.
The new recommendations are likely to pose a significant challenge for many blood donor organizations. The two experimental screening tests, for example, are relatively new.
Asked on a conference call with reporters about funding the new safeguards, Dr. Peter Marks, the director of the FDA's Center for Biologics Evaluation and Research, said, "I can't speak to the cost of implementation at this time."
Puerto Rico has been screening all blood donations since March. The Centers for Disease Control and Prevention in June found a surprisingly high percentage of donors had signs of active infection with the Zika virus.
This month, after the first cases of local transmission in Miami, some blood banks near Zika hot zones in Florida began screening blood donations. According to Marks, one donation contaminated with the virus had been found in recent weeks in the state.
The contaminated blood was discarded. "The system worked correctly," Marks said.