Interim guidance for interpretation of Zika Virus antibody test results
Centres for Disease Control and Prevention (CDC) Interim Guidance 2016
This guidance concerns the use of Zika virus diagnostic tests using antibodies. Suspected Zika virus disease infection is confirmed with a positive real-time reverse transcription–polymerase chain reaction (rRT-PCR), but a negative result does not exclude infection. Cases with negative rRT-PCR should undergo antibody testing to identify additional recent Zika virus infections. If immunoglobulin (Ig) M test results are positive, equivocal, or inconclusive, performing a plaque reduction neutralization test (PRNT) is needed to confirm the diagnosis. PRNT might not discriminate between anti-Zika virus antibodies and cross- reacting antibodies in all persons who have been previously infected with or vaccinated against a related flavivirus. Therefore, a more conservative approach to interpreting PRNT results is now recommended to reduce the possibility of misdiagnosis of either Zika or dengue virus infection. Pregnant women with laboratory evidence of a recent Zika virus infection or flavivirus infection should be evaluated and managed for adverse pregnancy outcomes and reported to the appropriate Zika virus pregnancy registry. Health care providers should consult with state or local public health authorities for assistance in interpreting test results.