In 2015, Zika virus (ZIKV) reemerged as a public health threat, with resultant Congenital Zika Syndrome (CZS) in a subset of babies exposed to the virus in utero. A causal link between ZIKV and brain malformations has been established; however; the variability in extent of these malformations and their impact on long term neurocognitive outcomes remains unknown. The goal of our investigation is to better understand the variability in neurodevelopmental outcomes in infants who were exposed to ZIKV in utero. While microcephaly is the most severe and obvious neurodevelopmental impact associated with in utero ZIKV exposure, evidence suggests a spectrum of developmental impacts from mild to severe. Thus, sensitive measures are needed to determine the true incidence and nature of the impact on neurocognitive development. We investigated cognitive outcomes in a well characterized cohort of ZIKV-exposed children in Grenada using sensitive measures of cognition, language, fine & gross motor skills, behavior, attention, and social-emotional reactivity. Although data collection is ongoing, our preliminary results provide a snapshot of the neuropsychological impact of ZIKV exposure in human infants in their first two years of life.
The developing Caribbean island nation of Grenada experienced a large ZIKV outbreak from April 2016 through March 2017. Our research group collected survey data and serum samples from pregnant women and their offspring, as babies potentially exposed to ZIKV during intrauterine life were being born in Grenada. We assessed these children shortly after birth and are assessing them at 12 months of age for neurodevelopmental delays using the Oxford Neurodevelopment Assessment (OX-NDA) – an internationally validated neurocognitive screening tool. We are continuing to follow these children in order to characterize their neurodevelopmental functioning at 22-26 months of age, using Electroencephalography (EEG) assessments and the INTERGROWTH-21st Neurodevelopment Assessment (INTER-NDA), an internationally validated comprehensive measure of cognition, fine and gross motor skills, expressive and receptive language, behavior, and social-emotional reactivity. The primary goal of this ongoing investigation is to ensure that children with in utero ZIKV exposure reach their full potential by identifying and addressing developmental challenges as early as possible.
Another important goal of this work is to build capacity for neurodevelopmental assessment and arboviral research in at St. Georges’ University (SGU) and Windward Islands Research and Education Foundation (WINDREF) a non-profit research institute located on the SGU campus. We have built research capacity in vector-borne diseases and neurodevelopment in the Caribbean Region and have established a Regional Center of Excellence in Child Neurodevelopment. We have also been successful in building capacity and links with the Ministry of Health in Grenada and other Grenadian neurodevelopmental specialists. Our collective work has also been recognized for excellence by international societies, such as the American Society of Tropical Medicine and Hygiene.
Funding provided by USAID Maternal and Child Survival Program. 4/2018 – 12/2018, by the Stanford University School of Medicine Child Health Research Institute (CHRI) Grant, and by a philanthropic gift from an anonymous individual donor. 10/2029 – 4/2022.