Approach to initial evaluation and follow-up of the infant born to a mother with possible Zika virus exposure during pregnancy*^[1,2]

CZS: congenital Zika syndrome; ABR: auditory brainstem response; CBC: complete blood count; LFTs: liver function tests; OFC: occipitofrontal circumference; rRT-PCR: real-time reverse transcription polymerase chain reaction; IgM: immunoglobulin M; ELISA: enzyme-linked immunosorbent assay; CSF: cerebrospinal fluid.
* This includes infants born to mothers with laboratory evidence of Zika virus infection during pregnancy and infants with findings suggestive of congenital Zika virus infection in the setting of a maternal epidemiologic link (eg, residence in or recent travel to an area where mosquito-borne transmission of Zika virus infection has been reported or unprotected sexual contact with a person with recent Zika virus exposure). Refer to UpToDate topic on Zika virus infection in pregnancy for additional details.
¶ The initial clinical evaluation can be completed before hospital discharge or as an outpatient, taking into account hospital capabilities and needs of the family. Transfer to a facility with access to pediatric subspecialty care typically is not necessary unless there is an urgent clinical need (eg, refractory seizures, respiratory failure). For severely affected infants who are receiving palliative care, providers and families may choose to forego some of these consultations and evaluations. Refer to UpToDate topic on congenital Zika virus infection for additional details.
Δ Zika virus testing in the infant includes serum and urine Zika virus rRT-PCR testing and serum Zika virus IgM ELISA. If CSF is obtained for other studies, rRT-PCR testing for Zika virus RNA and Zika virus IgM should be performed on CSF. The initial samples should be collected from the infant within the first few days after birth, if possible. Testing is positive if the rRT-PCR is positive in any of the samples collected at birth. Negative rRT-PCR with positive IgM (including "positive," "presumptive positive," "possible positive," or "equivocal") indicates probable congenital Zika virus infection. If both rRT-PCR and IgM testing are negative, congenital Zika virus infection is unlikely. Negative Zika virus testing should prompt a thorough evaluation for other causes of microcephaly or other findings, if present. Refer to UpToDate topic on congenital Zika virus infection for further details.
◊ Evaluation for other causes of congenital anomalies is based on the specific findings and may include testing for other congenital infections and/or testing for genetic causes of microcephaly. For further details, refer to separate UpToDate content on congenital (TORCH) infections and evaluation of microcephaly.
§ Laboratory evidence of maternal Zika virus infection includes positive rRT-PCR in any clinical specimen or positive Zika virus IgM with confirmatory neutralizing antibody titers. Refer to UpToDate content on Zika virus infection in pregnancy for further details.
¥ Infants with confirmed or probable Zika virus infection who pass the initial newborn hearing screen using only otoacoustic emissions methodology should have automated ABR performed by age 1 month.
‡ Additional outpatient follow-up is based on the clinical findings. For severely affected infants who are receiving palliative care, providers and families may choose to forego some of these consultations and evaluations.