While the Zika virus is primarily transmitted by mosquito bites, it could also be passed through blood transfusion. To ensure that nobody who needs transfusion in the US gets infected, the US Food and Drug Administration has approved the first test that can screen Zika in blood donations. The cobas Zika test can detect the virus' RNA in plasma taken from donated whole blood and blood components. It can't be used to diagnose infection, but it can keep the country's blood supply Zika-free.
The DFA actually allowed some clinics to use the technique as an experimental method to screen blood donations back in 2016 when the virus started spreading in Puerto Rico. Thanks to that testing period, the FDA was able to prove that the test can indeed effectively and accurately spot the virus. According to additional tests in five external laboratories, its clinical specificity (or the frequency in negative results in uninfected subjects) is 99 percent. Now that it's officially been approved, clinics and hospitals around the country can use it to make sure their blood supply won't infect anyone with the virus.
FDA Center for Biologics Evaluation and Research director Peter Marks said in a statement:
"Today's action represents the first approval of a Zika virus detection test for use with screening the nation's blood supply. Screening blood donations for the Zika virus is critical to preventing infected donations from entering the U.S. blood supply. Today's approval is the result of a commitment by the manufacturer to work rapidly and collaboratively with the FDA and the blood collection industry to respond to a public health crisis and ensure the safety of blood in the U.S. and its territories."