Announcement: Guidance for U.S. Laboratory Testing for Zika Virus Infection: Implications for Health Care Providers

CDC has released updated guidance online for U.S. laboratory testing for Zika virus infection. The guidance is available at https://www.cdc.gov/zika/laboratories/lab-guidance.html. Frequently asked questions are addressed at https://www.cdc.gov/zika/laboratories/lab-guidance-faq.html. This guidance updates recommendations for testing of specimens by U.S. laboratories for possible Zika virus infection. Major updates to the guidance with clinical implications for health care providers include the following:

• In addition to specimens listed in CDC’s clinical guidance (1–3), whole blood can now be tested for Zika virus RNA in accordance with the Emergency Use Authorization (EUA) for Zika virus nucleic acid testing (NAT)* for a) symptomatic persons tested up to 14 days after onset of symptoms, b) asymptomatic pregnant women tested within 14 days of last possible Zika virus exposure, and c) infants tested for congenital Zika virus infection.

• The use of plaque reduction neutralization testing (PRNT) for confirmation of Zika virus infection, including in pregnant women and infants, is currently not routinely recommended in Puerto Rico.

• PRNT can be used to test for congenital Zika virus infection in children aged ≥18 months; maternally derived antibodies in the infant are expected to have waned, and therefore PRNT results will reflect infant-derived antibodies. Local health departments should determine when to implement testing of infants aged ≥18 months based on local context, including the regional circulation of similar flaviviruses, laboratory capacity, and other epidemiologic circumstances.

The updated guidance for laboratories has clinical implications for health care providers caring for pregnant women with possible Zika virus exposure, infants with possible congenital Zika virus infection, and nonpregnant persons with suspected Zika virus disease.