Tag Archive for: congenital Zika syndrome

Members of the Columbia Zika virus research team

School entry neurodevelopmental outcomes of Zika-exposed Colombian children

Members of the Columbia Zika virus research team

The Children’s National Hospital Zika Research Team and collaborators from Biomelab, in Barranquilla, Colombia take a picture after a study visit in Sabanalarga, Colombia following the neurodevelopmental outcomes of children who had in utero exposure to Zika virus. Pictured from Children’s National Hospital: Dr. Sarah Mulkey, Regan Andringa-Seed, Margarita Arroyave-Wessel, and Dr. Madison Berl.

The long-term neurodevelopmental effects of antenatal Zika virus (ZIKV) exposure in children without congenital Zika syndrome (CZS) remain unclear, as few children have been followed to the age of starting primary school.

In a new study published in Pathogens, researchers found children with in utero ZIKV exposure appear to have an overall positive developmental trajectory at 4 to 5 years of age but may experience risks to neurodevelopment in areas of emotional regulation and adaptive mobility.

The hold up in the field

Children who were born during the ZIKV epidemic and who had in utero exposure to ZIKV are only now at the age to start school. Child neurodevelopmental outcome data has not been reported at the age of school entry for children with antenatal ZIKV exposure who do not have the severe birth defects of CZS.

“As these children approach the early school-age years, we aim to examine whether there are neurodevelopmental differences in executive function, motor ability, language development or scholastic skills as compared to a group of unexposed control participants from the same communities in Colombia,” says Sarah Mulkey, M.D., Ph.D., prenatal-neonatal neurologist in The Zickler Family Prenatal Pediatrics Institute at Children’s National Hospital and lead author of the study.

Moving the field forward

Building on previous findings, this study presents the longitudinal outcomes of a well-characterized Colombian cohort of ZIKV-exposed children without CZS at ages 4 to 5 years. These children have been seen for neurodevelopmental follow-up as infants and toddlers at approximately 6 months, 18 months and 3 years of age as part of an international collaboration between researchers in Barranquilla, Colombia and at Children’s National beginning in 2016. The objective of this study was to assess the multi-domain neurodevelopmental outcomes in 4 to 5-year-old children with antenatal ZIKV exposure without CZS compared to unexposed controls in Colombia.

Why we’re excited

Many of the children who had antenatal ZIKV exposure are making good progress in multiple areas of their neurodevelopment. However, the researchers found that children with antenatal ZIKV exposure have differences in areas of emotional regulation, executive function, mood and behavior which may relate to virus exposure during their early brain development.

“These areas of brain function are important for future academic achievement, employment, mental health and social relationships,” says Dr. Mulkey. “So, it will be important to continue to follow these children at older ages when they start school.”

Children’s National leads the way

Children’s National is a leader in conducting outcome studies of children born following antenatal ZIKV exposure. This study follows children in Colombia who are now 5 years old who were first studied while they were in the womb. These children have contributed unique longitudinal understanding to early child neurodevelopment following in utero exposure to ZIKV.

Dr. Mulkey is committed to studying the long-term neurodevelopmental impacts that viruses like Zika and SARS-CoV-2 have on infants born to mothers who were infected during pregnancy through research with the Congenital Infection Program at Children’s National and in collaboration with colleagues in Colombia.

Additional Children’s National authors include Meagan Williams M.S.P.H., C.C.R.C., senior research coordinator; Regan Andringa-Seed, clinical research coordinator, Margarita Arroyave-Wessel, clinical research coordinator; L. Gilbert Vezina, M.D., director, Neuroradiology Program; Dorothy Bulas, M.D., chief, Diagnostic Imaging and Radiology; Robert Podolsky, biostatistician.

Researchers showing paintings of zika virus

Dr. Sarah Mulkey and Children’s National clinical research coordinators in the Prenatal Pediatrics Institute and the Division of Pediatric Infectious Diseases display their paintings of the Zika virus. Pictured from left to right: Manuela Iglesias, Elizabeth Corn, Dr. Sarah Mulkey, Emily Ansusinha and Meagan Williams.

Sarah Mulkey

Exposure to Zika in utero may produce neurodevelopmental differences

Sarah Mulkey

“There are still many unanswered questions about the long-term impacts of Zika on children exposed in utero,” says Sarah Mulkey, M.D., Ph.D., a prenatal-neonatal neurologist in the Prenatal Pediatrics Institute at Children’s National Hospital.

Children who are exposed to the Zika virus while in the womb, but who are not subsequently diagnosed with Zika-related birth defects and congenital Zika syndrome (CZS), may still display differences in some aspects of cognitive development, mood and mobility compared to unexposed children, reports a study published in Pediatric Research. These findings suggest that Zika-exposed children may need some additional support and monitoring as they get older.

“There are still many unanswered questions about the long-term impacts of Zika on children exposed in utero,” says Sarah Mulkey, M.D., Ph.D., a prenatal-neonatal neurologist in the Prenatal Pediatrics Institute at Children’s National Hospital and the study’s first author. “These findings are another piece of the puzzle that provides insight into the long-term neurodevelopment of children with prenatal Zika virus exposure. Further evaluation is needed as these children get older.”

It has not been clear how children who were exposed to the Zika virus in the womb during the 2015–2017 epidemic, but who did not develop CZS and serious neurological complications, will develop as they get older.

Dr. Mulkey and colleagues examined the neurodevelopment of 55 children aged 3-5 years who were exposed to Zika in the womb in Sabanalarga, Colombia, and compared them to 70 control children aged 4-5 years who had not been exposed to Zika. Assessments occurred between December 2020 and February 2021. Health professionals tested the children’s motor skills (such as manual dexterity, aiming and catching, and balance) and their readiness for school (including knowledge of colors, letters, numbers and shapes). Parents completed three questionnaires providing information about their child’s cognitive function (such as memory and emotional control), behavioral and physical conditions (such as responsibility and mobility), and their parenting experience (including whether they felt distress).

Parents of Zika-exposed children reported significantly lower levels of mobility and responsibility compared to control children, although differences in cognitive function scores were not significant. Additionally, parents of 6 (11%) Zika-exposed children reported mood problems compared to 1 (1%) of control children, and Zika-exposed parents were significantly more likely to report parental distress.

Professional testing revealed no significant differences in the Zika-exposed children’s manual dexterity, such as their ability to catch an object or post a coin through a slot, compared to the control children. Both Zika-exposed and control children also scored lowly on readiness for school.

The authors highlight that parental responses may have been influenced by the Zika-exposed children’s parents’ perceptions or increased worry about the development of their child. Some differences in results may also have been caused by the age – and therefore developmental – differences between the groups of children.

The authors conclude that while these Zika-exposed children are making progress as they develop, they may need additional support as they prepare to start school.

Dr. Mulkey is committed to studying the long-term neurodevelopmental impacts that viruses like Zika and SARS-CoV-2 have on infants born to mothers who were infected during pregnancy through research with the Congenital Infection Program at Children’s National and in collaboration with colleagues in Colombia.

sleeping baby

False negatives: Delayed Zika effects in babies who appeared normal at birth

sleeping baby

Colombian infants exposed to Zika virus in the womb showed neurodevelopmental delays as toddlers, despite having “normal” brain imaging and head circumference at birth, a finding that underscores the importance of long-term neurodevelopmental follow-up for Zika-exposed infants.

Colombian infants exposed to Zika virus in the womb showed neurodevelopmental delays as toddlers, despite having “normal” brain imaging and head circumference at birth, a finding that underscores the importance of long-term neurodevelopmental follow-up for Zika-exposed infants, according to a cohort study published online Jan. 6, 2020, in JAMA Pediatrics.

“These infants had no evidence of Zika deficits or microcephaly at birth. Neurodevelopmental deficits, including declines in mobility and social cognition, emerged in their first year of life even as their head circumference remained normal,” says Sarah B. Mulkey, M.D. Ph.D., a fetal/neonatal neurologist at Children’s National Hospital and the study’s first author. “About one-third of these newborns who underwent postnatal head ultrasound had nonspecific imaging results, which we believe are the first published results finding a link between subtle brain injuries and impaired neuromotor development in Zika-exposed children.”

The multi-institutional research group led by Children’s National enrolled pregnant women in Atlántico Department, which hugs the Caribbean coast of Colombia, who had been exposed to Zika, and performed a series of fetal magnetic resonance images (MRI) and ultrasounds as their pregnancies progressed.

Even though their mothers had laboratory-confirmed Zika infections, 77 out of 82 of their offspring were born with no sign of congenital Zika syndrome, a constellation of birth defects that includes severe brain abnormalities, eye problems and congenital contractures, and 70 underwent additional testing of neurodevelopment during infancy. These apparently normal newborns were born between Aug. 1, 2016, and Nov. 30, 2017, at the height of the Zika epidemic, and had normal head circumference.

When they were 4 to 8 months or 9 to 18 months of age, the infants’ neurodevelopment was evaluated using two validated tools, the Warner Initial Developmental Evaluation of Adaptive and Functional Skills (a 50-item test of such skills as self-care, mobility, communication and social cognition) and the Alberta Infant Motor Scale (a motor examination of infants in prone, supine, sitting and standing positions). Some infants were assessed during each time point.

Women participating in the study were highly motivated, with 91% following up with appointments, even if it meant traveling hours by bus. In addition to Children’s National faculty traveling to Colombia to train staff how to administer the screening instruments, videotaped assessments, MRIs and ultrasounds were read, analyzed and scored at Children’s National. According to the study team, the U.S. scoring of Alberta Infant Motor Scale tests administered in Colombia is also unprecedented for a research study and offers the potential of remote scoring of infants’ motor skill maturity in regions of the world where pediatric specialists, like child neurologists, are lacking.

“Normally, neurodevelopment in infants and toddlers continues for years, building a sturdy neural network that they later use to carry out complex neurologic and cognitive functions as children enter school,” Dr. Mulkey adds. “Our findings underscore the recommendations by the Centers for Disease Control and Prevention (CDC) that all infants exposed to Zika in the womb undergo long-term follow-up, providing an opportunity to intervene earlier.”

An accompanying editorial by CDC staffers concurs, saying the study reported “intriguing data” that add “to the growing evidence of the need for long-term follow-up for all children with Zika virus exposure in utero to ensure they receive the recommended clinical evaluations even when no structural defects are identified at birth.”

In addition to Dr. Mulkey, study co-authors include Margarita Arroyave-Wessel, MPH, Dorothy I. Bulas, M.D., chief of Diagnostic Imaging and Radiology, JiJi Jiang, MS, Stephanie Russo, BS, Robert McCarter, ScD, research section head, design and biostatistics,  Adré J. du Plessis, M.B.Ch.B., MPH, chief of the Division of Fetal and Transitional Medicine, and co-Senior Author, Roberta L. DeBiasi, MD, MS, chief of the Division of Pediatric Infectious Diseases, all of Children’s National; Colleen Peyton, PT, DPT, of Northwestern University; Yamil Fourzali, M.D., of Sabbag Radiologos, Barranquilla, Colombia; Michael E. Msall, M.D., of University of Chicago Comer Children’s Hospital; and co-Senior Author, Carlos Cure, M.D., BIOMELab, Barranquilla, Colombia.

Funding for the research described in this post was provided by the Thrasher Research Fund, the National Institutes of Health under award Nos. UL1TR001876 and KL2TR001877, and the Leadership Education in Neurodevelopmental and Related Disorders Training Program under grant HRSA/MCHB T73 MC11047.

zika virus

Neuroimaging essential for Zika cases

zika virus

About three years ago, Zika virus emerged as a newly recognized congenital infection, and a growing body of research indicates the damage it causes differs from other infections that occur in utero.

Seventy-one of 110 Brazilian infants at the highest risk for experiencing problems due to exposure to the Zika virus in the womb experienced a wide spectrum of brain abnormalities, including calcifications and malformations in cortical development, according to a study published July 31, 2019 in JAMA Network Open.

The infants were born at the height of Brazil’s Zika epidemic, a few months after the nation declared a national public health emergency. Already, many of the infants had been classified as having the severe form of congenital Zika syndrome, and many had microcephaly, fetal brain disruption sequence, arthrogryposis and abnormal neurologic exams at birth.

These 110 infants “represented a group of ZIKV-exposed infants who would be expected to have a high burden of neuroimaging abnormalities, which is a difference from other reported cohorts,” Sarah B. Mulkey, M.D., Ph.D., writes in an invited commentary published in JAMA Network Open that accompanies the Rio de Janeiro study. “Fortunately, many ZIKV-exposed infants do not have abnormal brain findings or a clinical phenotype associated with congenital Zika syndrome,” adds Dr. Mulkey, a fetal–neonatal neurologist in the Division of Fetal and Transitional Medicine at Children’s National in Washington, D.C.

Indeed, a retrospective cohort of 82 women exposed to Zika during their pregnancies led by a research team at Children’s National found only three pregnancies were complicated by severe fetal brain abnormalities. Compared with the 65% abnormal computed tomography (CT) or magnetic resonance imaging (MRI) findings in the new Brazilian study, about 1 in 10 (10%) of babies born to women living in the continental U.S. with confirmed Zika infections during pregnancy had Zika-associated birth defects, according to the Centers for Disease Control and Prevention.

“There appears to be a spectrum of brain imaging abnormalities in ZIKV-exposed infants, including mild, nonspecific changes seen at cranial US [ultrasound], such as lenticulostriate vasculopathy and germinolytic cysts, to more significant brain abnormalities, such as subcortical calcifications, ventriculomegaly and, in its most severe form, thin cortical mantle and fetal brain disruption sequence,” Dr. Mulkey writes.

About three years ago, Zika virus emerged as a newly recognized congenital infection, and a growing body of research indicates the damage it causes differs from other infections that occur in utero. Unlike congenital cytomegalovirus infection, cerebral calcifications associated with Zika are typically subcortical, Dr. Mulkey indicates. What’s more, fetal brain disruption sequence seen in Zika-exposed infants is unusual for other infections that can cause microcephaly.

“Centered on the findings of Pool, et al, and others, early neuroimaging remains one of the most valuable investigations of the Zika-exposed infant,” Dr. Mulkey writes, including infants who are not diagnosed with congenital Zika syndrome.  She recommends:

  • Cranial ultrasound as the first-line imaging option for infants, if available, combined with neurologic and ophthalmologic exams, and brainstem auditory evoked potentials
  • Zika-exposed infants with normal cranial ultrasounds do not need additional imaging unless they experience a developmental disturbance
  • Zika-exposed infants with abnormal cranial ultrasounds should undergo further neuroimaging with low-dose cranial CT or brain MRI.