FDA expands Zika screening
The government told all U.S. blood banks Friday to start screening for Zika, a major expansion intended to protect the nation’s blood supply from the mosquito-borne virus.
Previously, blood testing was mostly limited to parts of Florida and Puerto Rico, where Zika is spreading. Screening will initially extend to states along the Gulf Coast and a few others.
“There is still much uncertainty regarding the nature and extent of Zika virus transmission,” Dr. Peter Marks said in a Food and Drug Administration release. “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.”
Blood banks already test donations for HIV, hepatitis, West Nile and other blood-borne viruses. The Zika virus stays in the blood for about one week, but is thought to remain in other bodily fluids longer.
Though Zika is spread primarily through mosquito bites, there have been reports in Brazil of Zika transmission through transfusion. No such cases have been reported in the U.S. One Zika-positive blood donation, though, recently was intercepted in Florida, Marks said Friday.
“The donation was identified while the blood bag was still in quarantine, before it was released,” Marks told reporters on a media call. “The system worked correctly.”
Zika also can be spread through sex, and Dr. Marks said that played into the decision to expand testing. Current evidence suggests that infected men can spread the virus for several months through sex, and women can transmit it for several weeks.
Adding to the challenge is that 4 out of 5 people infected never develop symptoms, such as fever, joint pain and rash.
The Centers for Disease Control and Prevention on Friday reported the first U.S. case of a man spreading Zika through sex even though he never had any symptoms. The Maryland man had traveled to the Dominican Republic, one of the many countries in the Caribbean and Latin America hit with a Zika outbreak.
There have been nearly 2,500 cases of Zika in the U.S. linked to travel to outbreak areas.
Though the virus causes only a mild illness in most people, infection during pregnancy can lead to severe brain-related birth defects.
Blood testing began last month in parts of Florida after the first cases of homegrown Zika occurred in Miami. So far, there have been about 40 cases of Zika caused by mosquito bites in Florida. Health officials, however, don’t expect widespread outbreaks to occur in the U.S.
The FDA has authorized use of two experimental blood-screening tests for Zika, one made by Roche and another from Hologic Inc. and Grifols. Several testing sites are already voluntarily using the technology, including blood centers in Texas. The cost of adding Zika testing to the screening process is less than $10 per blood donation, according to officials at South Texas Blood and Tissue Center.
FDA officials said they do not anticipate any problems supplying the tests throughout the U.S.
The tropical mosquito that spreads Zika and other viruses is found along the southern U.S. Friday’s directive lists 11 states that will need to begin screening blood in the next month because of their location or because of the influx of travelers from Zika outbreak countries.
On the list: Alabama, Arizona, California, Georgia, Hawaii, Louisiana, Mississippi, New Mexico, New York, South Carolina and Texas.
All other U.S. states and territories will have three months to comply.