FDA advises Zika testing for all blood donations in U.S.

The U.S. Food and Drug Administration (FDA) issued a revised Zika guidance on Friday, recommending all blood donations in the U.S. and its territories undergo testing for the mosquito-borne virus.

"There is still much uncertainty regarding the nature and extent of Zika virus transmission," Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said in a statement.

"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."

The FDA first issued guidance on Feb. 16 recommending that only areas with active Zika virus transmission screen donated whole blood and blood components for the virus, or halt blood collection.

The first local or non-travel related transmission of Zika virus in the U.S. by mosquitoes was reported from Puerto Rico in December 2015; and soon thereafter, local transmission was reported in American Samoa and the U.S. Virgin Islands.

In July 2016, the first cases of local or non-travel related transmission of Zika virus in the continental U.S. were reported in Miami-Dade County, Florida.

Zika is transmitted primarily by the Aedes mosquito, but it can also be spread by sexual contact.

Four out of five people infected with the Zika virus never develop symptoms, and when symptoms do occur, they may include fever, joint pain, maculopapular rash, and conjunctivitis.

In addition, Zika virus infection during pregnancy can cause serious birth defects and is associated with other adverse pregnancy outcomes.

"As new scientific and epidemiological information regarding Zika virus has become available, it's clear that additional precautionary measures are necessary," said Luciana Borio, the FDA's acting chief scientist. "We are issuing revised guidance for immediate implementation in order to help maintain the safety of the U.S. blood supply." Endit