FDA recommends donated blood be tested for Zika virus
Maryland urged to begin screenings within 12 weeks
As Zika infections continue to spread around the nation, the U.S. Food and Drug Administration recommended Friday that all donated blood and blood components soon be tested for the mosquito-borne virus.
Testing of the blood supply already has begun in Florida and in Puerto Rico, which is particularly hard-hit by the Zika outbreak. The FDA recommended 11 other states begin testing in the next month and the rest of the country — including Maryland — begin testing within12 weeks.
A unit of infected blood was found in recent weeks in Florida and removed from the supply, Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in a call with reporters Friday.
“At this time, the recommendation for testing the entire blood supply will help ensure that safe blood is available for all individuals who might need transfusion,” Marks said.
Zika will be added to a list of nine other contaminants, antibodies or viruses, including HIV and hepatitis, that blood banks and groups such as the American
Red Cross must test for when they accept a donation of whole blood, plasma or platelets.
The FDA estimates that about 1 million units of blood are donated a month nationwide. The cost of adding Zika tests isn’t known, but FDA officials called the move essential because the problems caused by the virus are so serious and scientists continue to learn about other effects.
“There is still much uncertainty regarding the nature and extent of Zika virus transmission,” Marks said.
The guidance expands the FDA’s recommendation earlier this year that areas with active Zika virus transmission screen whole blood and its components for Zika.
The primary concern about the virus is the risk to the fetuses of pregnant women and women who plan to become pregnant. Zika is known to cause microcephaly, which stunts the brains and skulls of fetuses in infected women. But other brain damage and other impacts on babies, as well as on adults, are being investigated.
“The situation is quickly evolving, and new science is coming out every day, and it makes sense that the FDA issued this guidance out of an abundance of caution,” said Dr. Leana Wen, Baltimore’s health commissioner. “The potential consequences are devastating to the unborn child.”
What’s more, Zika has been found in semen for up to six months, raising concerns at the FDA that men carrying the virus could infect potential blood donors.
Marks said only about 20 percent of people infected with Zika exhibit symptoms, which include fever and rash. That means many people who might be infected and haven’t been tested could donate tainted blood unknowingly, he said.
There have been 77 cases of Zika in Maryland, all of them related to travel. Nationally, there have been 2,517 cases of Zika reported to the U.S. Centers for Disease Control and Prevention, including more than 40 cases of Zika attributed to local mosquito bites in Florida. There have been 9,011 cases in U.S. territories including Puerto Rico.
People who know or believe they are infected with Zika should wait 120 days, or until their symptoms resolve, whichever is longer, before donating blood, the FDA said.
Donors who test positive for viruses are notified directly by the blood collection agencies, said Christopher Garrett, spokesman for the state Department of Health and Mental Hygiene.
The agencies also need to report the cases to the health department.
Andrew Pekosz, a professor in the departments of molecular microbiology and immunology, and environmental health sciences the Johns Hopkins University’s Bloomberg School of Public Health, said the new guidelines are timely — and necessary.
“It seems there have been a significant amount of cases that they should really be accounting for this in the screening process,” he said.
The Aedes aegypti mosquito has been the primary carrier and most efficient transmitter of Zika, Pekosz said. Outside of Florida and other Southern states, the risk of infection is far lower, he said.
Maryland isn’t likely to see many cases of local infection because the Aedes albopictus mosquito, also known as the Asian tiger mosquito, is more prevalent in the state.
Because of the lower risk, and because blood donations typically dip at the end of the summer, he said area residents should consider donating now.
“It certainly shouldn’t deter donating,” Pekosz said.
“In fact, it’s one of those times people should think about going in and donating blood.”