CDC updates diagnostic guidelines for congenital Zika virus infection




All infants who either exhibit abnormal clinical or neuroimaging findings consistent with possible Zika infection, or who exhibit normal phenotypes but are born to mothers who are positive for Zika virus infection during pregnancy, should undergo laboratory testing for the virus, according to updated diagnostic guidance from the CDC.

All infants should undergo a comprehensive physical exam at birth, as well as a neurologic examination, postnatal head ultrasound, and standard hearing tests to determine any phenotypic signs of congenital Zika infections (MMWR. ePub: 2016 Aug 19. doi: 10.15585/mmwr.mm6533e2).


Laboratory samples should be collected within 2 days of birth. Molecular testing should be done via a real-time reverse transcription–polymerase chain reaction (rRT-PCR), while serologic testing should be carried out via IgM. If the former test is positive, then the infant is Zika positive; however, if the rRT-PCR is negative but the IgM is positive, then the conclusion can only be a “probable” congenital Zika infection.

For infants with laboratory-confirmed or probable congenital Zika infection, the CDC recommends outpatient management and follow-up. For those who are found negative for Zika despite having other symptoms consistent with infection, the CDC advises continued evaluation to determine the cause of any congenital anomalies.

If an infant has no overt symptoms of Zika virus but is found to have laboratory-confirmed or probable Zika, they should be given routine newborn care along with auditory brainstem response (ABR) testing and an opthalmology examination within 1 month of birth. Infants with no overt signs of Zika and a lab-confirmed negative result can resume standard newborn care with no additional monitoring.

Outpatient care should begin with clear establishment of a medical home, followed by monitoring the child’s growth and developmental screenings at every well child visit, according to the CDC. Vision screening should be repeated at all well child visits; ABR should be repeated 4-6 months after initial testing.

“Use a standardized, validated developmental screening tool at 9 months as currently recommended, or earlier for any parental or provider concerns,” according to lead author Kate Russell, MD, of the CDC’s Epidemic Intelligence Service, and her coauthors.

Cranial ultrasound should be performed on all infants, regardless of how normal any prenatal cranial ultrasounds were. Previously, the CDC advised that if a third trimester prenatal cranial ultrasound showed no abnormalities, a postnatal cranial ultrasound was not needed.

The CDC continues to advise that a multidisciplinary approach be taken to evaluation, diagnosis, and potential treatment of infants with congenital Zika virus infection.

“Because the types of services needed to care for infants with congenital Zika syndrome are complex, CDC recommends coordinated care through a multidisciplinary team and established medical home,” according to the guidance. “As a critical component of patient care and early identification of any delays, families should be empowered to be active participants in their child’s monitoring and care.”

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