Nicola M. Parry, DVM
December 12, 2018
About 1 in 7 babies aged 12 to 18 months who were exposed to Zika virus before birth have significant neurodevelopmental problems, a study published online December 13 in the New England Journal of Medicine shows. "Among 131 children who were exposed to ZIKV [Zika virus] in utero and who underwent imaging, neurodevelopmental assessment, sensory organ assessment, or all of these tests, 19 (14%) were found to have severe neurodevelopmental delay (2 SD below the mean [±SD] score), sensory organ dysfunction, or both," write M. Elisabeth Lopes Moreira, MD, from Fundacao Oswaldo Cruz, Rio de Janeiro, Brazil, and colleagues in a research letter.
From September 2015 to June 2016 during the Zika virus epidemic in Rio de Janeiro, the researchers established a prospective study involving symptomatic pregnant women with confirmed Zika virus infection.
Moreira and colleagues then followed 182 children who had been exposed to the Zika virus during these pregnancies. In 131 (72%) of the children, the researchers performed at least one brain imaging exam, a complete eye exam, a Bayley Scales of Infant and Toddler Development (Bayley-III) screening exam, or a brainstem auditory evoked response test.
By age 12 to 18 months, 7 of 112 (6%) children whose brain imaging results were abnormal also had abnormal eye exams, and 6 of 49 (12%) children with abnormal results on brain imaging had abnormal hearing test results. Of 94 children who underwent brain imaging and Bayley-III screening, 11 (11.7%) had abnormal motor function, 15 (16.0%) had abnormal language development, and five (5.3%) had abnormal cognitive development.
In 19 (14.5%) of the 131 children, researchers found a severe neurodevelopmental defect in at least one of the three diagnostic assessment categories (imaging, neurodevelopmental screening, and sensory organ testing).
This 14.5% rate of problems is higher than has been reported in past studies, the authors write.
"Although a significant association was noted between normal results on brain imaging and higher Bayley-III scores, neuroimaging did not predict developmental delay in 2% of children and normal development in 16% of children," they add.
The study was supported by grants from the Departamento de Ciencia e Tecnologia do Ministerio da Saude do Brasil; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior; Brazilian National Council for Scientific and Technological Development; Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro; ZIKAlliance; the Thrasher Research Fund; the National Institute of Allergy and Infectious Diseases of the National Institutes of Health; the National Eye Institute of the National Institutes of Health; the Wellcome Trust and the United Kingdom Department for International Development; and the European Union Horizon 2020 research and innovation program. The authors have disclosed no relevant financial relationships.