One in 7 Babies Prenatally Exposed to Zika Virus Develop Birth Defects

Zika transmission from mother to unborn child during pregnancy is known to potentially cause Zika-associated birth defects such as microcephaly, eye abnormalities, hearing loss, and developmental delays. While Zika virus transmission is less prevalent in the United States in 2018, it is critical to research the long-term implications of congenital Zika, to better prepare for future infections.

A new report published in Vital Signs by the Centers for Disease Control and Prevention (CDC) found that 1 in 7 children > 1 years that were born from women with laboratory-confirmed Zika or potential Zika infection during pregnancy were identified as having either a Zika-associated birth defect, a neurodevelopment abnormality, or both as a result of congenital Zika virus. Some of these health issues were not noticeable at birth and became apparent as the infants grew older.

The data were obtained from the US Zika Pregnancy and Infant Registry (USZPIR), which includes information pertaining to pregnancies with laboratory evidence of confirmed or possible Zika virus infection and their infants.

This first-of-its-kind analysis focused on a population of 1450 children living in US territories including Puerto Rico and the US Virgin Islands who turned 1 year old prior to February 1, 2018. Receipt of reported follow-up care was observed in this population. Additionally, investigators reviewed data to identify Zika-associated birth defects and neurodevelopmental abnormalities possibly associated with congenital Zika virus infection.

Of the 1450 children included in the analysis, 87 (6%) had at least 1 Zika-associated birth defect, which is a more than 30-fold increase over the baseline (0.16%) frequency of brain and eye abnormalities potentially related to Zika infection among infants. Furthermore, 136 (9%) of children had a neurodevelopmental abnormality thought to potentially be associated with congenital Zika. The data indicate 20 (1%) children had both a Zika associated birth defect and a neurodevelopmental abnormality.

As for follow-up care, of the 1450 children assessed, 95% had at least 1 physical examination with a health care provider after 2 weeks of life, 76% underwent a developmental screening or evaluation, and 60% had neuroimaging. Additionally, 48% underwent an automated auditory brainstem response-based hearing test and 36% received an ophthalmologic evaluation.

Importantly, among the 1386 children who did not have microcephaly identified at birth, 822 (59%) received neuroimaging, including 14 (2%) who had at least 1 brain anomaly identified, the authors write. Furthermore, among the 494 (46%) of children who received an ophthalmologic evaluation, 12 (2%) had at least 1 eye anomaly identified. As such, the investigators conclude that if these infants did not receive this follow-up care, their anomalies would have gone undetected.

Early detection of abnormalities is essential for improving health outcomes in children; to do that, careful monitoring and evaluation of children born to mothers with laboratory evidence of confirmed Zika virus infection during pregnancy is needed. Early referral to intervention services has the potential to improve outcomes in these patients as some abnormalities associated with Zika can be reversed. For example, if a child has issues with their vision, he/she could receive a prescription for corrective glasses, which could prevent further damage from occurring.

The CDC is encouraging all health care providers to be cognizant of potential birth defects or abnormalities in young children that could have been exposed to Zika during pregnancy.

“It is essential that health care providers who care for children have access to information regarding maternal exposure to Zika virus infection during pregnancy,” the authors write in the report. “This will improve the identification of children born to mothers with laboratory evidence of confirmed or possible Zika virus infection during pregnancy so that they can receive recommended post-natal evaluations.”

The CDC has updated the recommendations for preventing the sexual transmission of Zika, according to Tuesday’s telebriefing. Previous recommendations suggested that couples with a male partner who has the virus or traveled to an area with Zika use a condom or avoid having sex for at least 6 months. The new recommendations suggest condom use for 3 months following a male partner’s exposure to Zika.