Posts

zika virus

The importance of following the Zika population long-term

zika virus

Invited commentary by Sarah Mulkey, M.D., Ph.D., prenatal-neonatal neurologist in the Division of Prenatal Pediatrics at Children’s National Hospital, emphasizes importance of studying the Zika population long term.

A simple measuring tape could be the key to identifying which children could develop neurological and developmental abnormalities from Zika virus exposure during gestation. This is according to an invited commentary published July 7, 2020 in JAMA Network Open and written by Sarah Mulkey, M.D., Ph.D., prenatal-neonatal neurologist in the Division of Prenatal Pediatrics at Children’s National Hospital.

Zika virus (ZIKV), first isolated in 1947 in the Ziika Forest in Uganda, made headlines in 2015-2016 for causing a widespread epidemic that spread through parts of North and South America, several islands in the Pacific and parts of Southeast Asia. Although previously linked with no or mild symptoms, researchers discovered during this epidemic that Zika can cross from a pregnant woman to her gestating fetus, leading to a syndrome marked by microcephaly (decreased brain growth), abnormal neurologic tone, vision and hearing abnormalities and joint contractures.

“For the 90% to 95% of ZIKV-exposed infants who fortunately were not born with severe abnormalities at birth and were normocephalic, our hope was that these children would have normal neurodevelopmental outcomes,” Dr. Mulkey writes in the commentary. “Unfortunately, this has not been the case.”

Her commentary expands on a study in the same issue entitled “Association between exposure to antenatal Zika virus and anatomic and neurodevelopmental abnormalities in children” by Cranston et al. In this study, the researchers find that head circumference — a simple measure taken regularly at postnatal appointments in the U.S. — can provide insight into which children were most likely to develop neurologic abnormalities. Their findings show that 68% of those whose head circumference was in the “normal” range at birth developed neurologic problems. Those whose head circumference was at the upper end of this range were significantly less likely to have abnormalities than those at the lower end.

Just this single measurement offers considerable insight into the risk of developing neurologic problems after Zika exposure. However, notes Dr. Mulkey, head circumference growth trajectory is also key. Of the 162 infants whose heads were initially in the normocephalic range at birth, about 10.5% went on to develop microcephaly in the months after birth.

“Because early head growth trajectory is associated with cognitive outcomes in early childhood,” Dr. Mulkey writes, “following the head circumference percentile over time can enable recognition of a child with increased risk for poor outcome who could benefit from early intervention therapies.”

This simple assessment could be significantly augmented with neuroimaging, she adds. The study by Cranston et al., as well as others in the field, have shown that brain imaging often reveals problems in ZIKV-exposed children, such as calcifications and cerebral atrophy, even in those with normal head circumferences. This imaging doesn’t necessarily need to take place at birth, Dr. Mulkey says. Postnatal development of microcephaly, failure to thrive or developmental delay can all be triggers for imaging later on.

Together, Dr. Mulkey says, the study by Cranston et al. and others that focus on ZIKV-exposed children support the need for following these patients long term. Children exposed to ZIKV in the epidemic nearly five years ago are now approaching school age, a time fraught with more complicated cognitive and social demands. Through her own research at Children’s National’s Congenital Zika Virus Program and collaboration with colleagues in Colombia, Dr. Mulkey is following multiple cohorts of ZIKV exposed children as they grow. She recently published a study on neurological abnormalities in one of these cohorts in JAMA Pediatrics in January 2020.

“It’s really important to follow these children as long as possible so we’ll really know the outcomes of this virus,” Dr. Mulkey says.

Vittorio Gallo and Mark Batshaw

Children’s National Research Institute releases annual report

Vittorio Gallo and Marc Batshaw

Children’s National Research Institute directors Vittorio Gallo, Ph.D., and Mark Batshaw, M.D.

The Children’s National Research Institute recently released its 2019-2020 academic annual report, titled 150 Years Stronger Through Discovery and Care to mark the hospital’s 150th birthday. Not only does the annual report give an overview of the institute’s research and education efforts, but it also gives a peek in to how the institute has mobilized to address the coronavirus pandemic.

“Our inaugural research program in 1947 began with a budget of less than $10,000 for the study of polio — a pressing health problem for Washington’s children at the time and a pandemic that many of us remember from our own childhoods,” says Vittorio Gallo, Ph.D., chief research officer at Children’s National Hospital and scientific director at Children’s National Research Institute. “Today, our research portfolio has grown to more than $75 million, and our 314 research faculty and their staff are dedicated to finding answers to many of the health challenges in childhood.”

Highlights from the Children’s National Research Institute annual report

  • In 2018, Children’s National began construction of its new Research & Innovation Campus (CNRIC) on 12 acres of land transferred by the U.S. Army as part of the decommissioning of the former Walter Reed Army Medical Center campus. In 2020, construction on the CNRIC will be complete, and in 2012, the Children’s National Research Institute will begin to transition to the campus.
  • In late 2019, a team of scientists led by Eric Vilain, M.D., Ph.D., director of the Center for Genetic Medicine Research, traveled to the Democratic Republic of Congo to collect samples from 60 individuals that will form the basis of a new reference genome data set. The researchers hope their project will generate better reference genome data for diverse populations, starting with those of Central African descent.
  • A gift of $5.7 million received by the Center for Translational Research’s director, Lisa Guay-Woodford, M.D., will reinforce close collaboration between research and clinical care to improve the care and treatment of children with polycystic kidney disease and other inherited renal disorders.
  • The Center for Neuroscience Research’s integration into the infrastructure of Children’s National Hospital has created a unique set of opportunities for scientists and clinicians to work together on pressing problems in children’s health.
  • Children’s National and the National Institute of Allergy and Infectious Diseases are tackling pediatric research across three main areas of mutual interest: primary immune deficiencies, food allergies and post-Lyme disease syndrome. Their shared goal is to conduct clinical and translational research that improves what we know about those conditions and how we care for children who have them.
  • An immunotherapy trial has allowed a little boy to be a kid again. In the two years since he received cellular immunotherapy, Matthew has shown no signs of a returning tumor — the longest span of time he’s been tumor-free since age 3.
  • In the past 6 years, the 104 device projects that came through the National Capital Consortium for Pediatric Device Innovation accelerator program raised $148,680,256 in follow-on funding.
  • Even though he’s watched more than 500 aspiring physicians pass through the Children’s National pediatric residency program, program director Dewesh Agrawal, M.D., still gets teary at every graduation.

Understanding and treating the novel coronavirus (COVID-19)

In a short period of time, Children’s National Research Institute has mobilized its scientists to address COVID-19, focusing on understanding the virus and advancing solutions to ameliorate the impact today and for future generations. Children’s National Research Institute Director Mark Batshaw, M.D., highlighted some of these efforts in the annual report:

  • Eric Vilain, M.D., Ph.D., director of the Center for Genetic Medicine Research, is looking at whether or not the microbiome of bacteria in the human nasal tract acts as a defensive shield against COVID-19.
  • Catherine Bollard, M.D., MBChB, director of the Center for Cancer and Immunology Research, and her team are seeing if they can “train” T cells to attack the invading coronavirus.
  • Sarah Mulkey, M.D., Ph.D., an investigator in the Center for Neuroscience Research and the Fetal Medicine Institute, is studying the effects of, and possible interventions for, coronavirus on the developing brain.

You can view the entire Children’s National Research Institute academic annual report online.

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.