A 'Healthy' Baby With Developmental Delay: Could It Be Zika?

The full range of long-term health problems caused by congenital Zika virus exposure might not be apparent at birth or recognized until infancy and early childhood. In some cases, infants born to women with possible Zika virus exposure or laboratory evidence of possible Zika virus infection during pregnancy are not identified as having congenital Zika virus exposure at birth, and might present with symptoms later. Healthcare providers should be alert to the possibility of congenital Zika virus infection in these infants and monitor them according to guidelines to help identify problems as early as possible.

Possible Zika virus exposure includes travel to or residence in an area with mosquito-borne Zika virus transmission or having sex without the use of condoms with a partner who has traveled to or resides in an area with mosquito-borne Zika virus transmission. CDC has current updates on travel recommendation related to Zika virus. Laboratory evidence of possible Zika virus infection during pregnancy is defined as (1) Zika virus infection detected by a Zika virus ribonucleic acid (RNA) nucleic acid amplification test (NAAT) on any maternal, placental, or fetal specimen (referred to as "NAAT-confirmed"), or (2) diagnosis of Zika virus infection, timing of infection cannot be determined or unspecified flavivirus infection, timing of infection cannot be determined by serologic testing on a maternal specimen (ie, positive/equivocal Zika virus immunoglobulin M [IgM] and Zika virus plaque reduction neutralization test [PRNT] titer ≥ 10, regardless of dengue virus PRNT value; or negative Zika virus IgM, and positive or equivocal dengue virus IgM, and Zika virus PRNT titer ≥ 10, regardless of dengue virus PRNT titer). The use of PRNT for confirmation of Zika virus infection, including in pregnant women, is not routinely recommended in Puerto Rico.

Possible Zika virus exposure includes travel to or residence in an area with mosquito-borne Zika virus transmission or having sex without the use of condoms with a partner who has traveled to or resides in an area with mosquito-borne Zika virus transmission. CDC has current updates on travel recommendation related to Zika virus.

Laboratory evidence of possible Zika virus infection during pregnancy is defined as (1) Zika virus infection detected by a Zika virus ribonucleic acid (RNA) nucleic acid amplification test (NAAT) on any maternal, placental, or fetal specimen (referred to as "NAAT-confirmed"), or (2) diagnosis of Zika virus infection, timing of infection cannot be determined or unspecified flavivirus infection, timing of infection cannot be determined by serologic testing on a maternal specimen (ie, positive/equivocal Zika virus immunoglobulin M [IgM] and Zika virus plaque reduction neutralization test [PRNT] titer ≥ 10, regardless of dengue virus PRNT value; or negative Zika virus IgM, and positive or equivocal dengue virus IgM, and Zika virus PRNT titer ≥ 10, regardless of dengue virus PRNT titer). The use of PRNT for confirmation of Zika virus infection, including in pregnant women, is not routinely recommended in Puerto Rico.

The following cases present a range of clinical situations. Would you know how to manage these infants appropriately?

Case 1: Confirmed Maternal Infection, Healthy Infant

A mother brings her 2-week-old son to the pediatrician for the first visit after discharge from the birth hospital. Eighteen weeks into her pregnancy, she had visited a clinic after experiencing 3 days of fever, rash, and conjunctival erythema shortly after returning from visiting family in an area experiencing a Zika outbreak at that time. At 18 weeks' gestation, polymerase chain reaction (PCR) testing for Zika virus RNA on maternal serum was positive; ultrasound examinations during the second and third trimesters showed no fetal anomalies.

At birth, the infant's comprehensive physical examination and newborn hearing screen, performed using otoacoustic emissions (OAEs), were normal. Zika virus laboratory tests (PCR testing for Zika virus RNA on serum and urine and Zika-specific immunoglobulin M [IgM] on serum) performed on the infant at birth were negative.