CDC Releases Updated Zika Diagnostic Testing Guidance

The Centers for Disease Control and Prevention (CDC) just released updated guidance for Zika diagnostic testing.

The interim guidance provides diagnostic guidelines for urine tests done in public health laboratories. According to their media release, the CDC updated the guidance “based on preliminary data demonstrating that Zika virus can be found at higher levels or for longer duration in urine than in serum (blood).”

The current preferred test for Zika virus detection, real-time reverse transcription—polymerase chain reaction (rRT-PCR), produces rapid and highly specific results, however, recent data has shown that “Zika virus RNA is unlikely to be detected in serum after the first week of illness.”

Although reports have suggested that Zika virus RNA can be detected in urine “for at least two weeks after onset of symptoms,” the CDC states that “further investigation is needed to determine the sensitivity and utility of Zika virus rRT-PCR on urine specimens collected ≥14 days after onset of symptoms.”

Based on these findings, the CDC is recommending that “the Zika virus rRT-PCR be performed on urine collected <14 days after onset of symptoms in patients with suspected Zika virus disease” and “should be performed in conjunction with serum testing if using specimens collected <7 days after symptom onset.”

Healthcare professionals should note that a positive result in either specimen type provides evidence of a Zika virus infection.

The CDC will update the guidance as new data becomes available.