WASHINGTON – The Food and Drug Administration has recommended screening the entire US blood supply for the Zika virus, it announced today, noting that screening donated blood is already underway in Florida and Puerto Rico.
The new recommendation applies “across the board to anyone collecting blood,” explained Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research. This includes very large blood collection establishments, such as the American Red Cross, and some very small establishments, such as academic centers, he said. Expanded testing should remain in effect until the risk of transmitting the virus through blood transfusions is reduced.
“We’ve come to a critical juncture: the risk to the blood supply combined with the uncertainty about the nature and extent of Zika virus transmission,” Marks said. More than 40 cases of mosquito-transmitted infection have been reported in Florida.
Though scientists are still learning about the virus, they know that Zika is transmitted primarily by mosquitoes but can also be spread by sexual contact. For pregnant women, an infection could cause microcephaly, a serious birth defect.
“About 80 percent of people who have Zika may never have symptoms,” Marks said. Symptoms can include fever, joint pain, rash and red, irritated eyes.
Because an infection could be transmitted during sex, someone who does not have symptoms might spread the virus to an individual who then donates blood, and this could lead to an “amplification” of the crisis, sai Marks.
The FDA issued its first Zika virus blood screening recommendation in February for areas with active transmission. At that time, the agency advised screening blood and blood components for the virus or stopping blood collection completely in areas of active transmission.
The nation’s first local, non-travel-related infection of Zika virus occurred in Puerto Rico in December. Shortly after, American Samoa and the US Virgin Islands reported similar locally transmitted infections. In July, Florida’s Miami-Dade County reported its own first case of a local mosquito-transmitted Zika infection.
With no FDA-licensed tests available for Zika, two investigational tests are being used to screen blood collected in the United States and Puerto Rico. Roche Molecular Systems’ test became available in April, and Hologic Inc.’s test was put to use in June.
“The Cobas Zika test is a blood screening test for blood donations only,” Roche spokesman Bob Purcell said. He explained that this is not a diagnostic test.
Procleix, the blood screening test from Hologics and a partner company, is used by the American Red Cross in some of its labs. Procleix tests have been used to screen blood for HIV and hepatitis B and C for many years, Hologic spokeswoman Suzanne Clancy said.
