Agency has also given emergency authorisation to two new Zika blood tests

All incoming blood donations across the US should be tested for the Zika virus, even in states with no reported cases, according to the Food and Drug Administration (FDA). The FDA has also granted laboratories permission to use molecular blood tests developed by Roche and Hologic.

Early reports of a Zika outbreak emerged in Brazil last year. Although the infection often causes no symptoms, the virus has been linked to birth defects, such as abnormal brain development.

The epidemic has since spread across South America and parts of the US, with the World Health Organization now classifying Zika as a global public health emergency.

In February 2016, the FDA recommended that any states with reported Zika cases should screen all blood or blood component donations for the infection. The FDA has now revised this advice, stating all US territories should test blood samples for signs of the virus.

Skipping the standard approval process, the FDA has also granted Roche and Hologic emergency authorisation to distribute new Zika blood test to screening labs. Roche’s reverse transcriptase polymerase chain reaction (RT-PCR) test can generate a result within three hours and also be used on urine samples. Hologic’s test uses transcription-mediated amplification to detect Zika virus RNA.