Nonmicrocephalic Infants with Congenital Zika Syndrome Suspected Only after Neuroimaging Evaluation Compared with Those with Microcephaly at Birth and Postnatally: How Large Is the Zika Virus "Iceberg"?

Saxitoxin potentiates human neuronal cell death induced by Zika virus while sparing neural progenitors and astrocytes

The Zika virus (ZIKV) epidemic declared in Brazil between 2015 and 2016 was associated with an increased prevalence of severe congenital malformations, including microcephaly. The distribution of microcephaly cases was not uniform across the country, with a disproportionately higher incidence in the Northeast region (NE). Our previous work demonstrated that saxitoxin (STX), a toxin present in the drinking water reservoirs of the NE, exacerbated the damaging effects of ZIKV on the developing brain. We hypothesized that the impact of STX might vary among different neural cell types. While ZIKV infection caused severe damages on astrocytes and neural stem cells (NSCs), the addition of STX did not exacerbate these effects. We observed that neurons subjected to STX exposure were more prone to apoptosis and displayed higher ZIKV infection rate. These findings suggest that STX exacerbates the harmful effects of ZIKV on neurons, thereby providing a plausible explanation for the heightened severity of ZIKV-induced congenital malformations observed in Brazil's NE. This study highlights the importance of understanding the interactive effects of environmental toxins and infectious pathogens on neural development, with potential implications for public health policies.

Understanding the multidimensional neurodevelopmental outcomes in children after congenital Zika virus exposure

Since 2016, international research groups have focused on assessing outcomes of children with in utero Zika virus (ZIKV) exposure. While the more severe outcomes of congenital Zika syndrome (CZS) occur in up to 10% of children with antenatal exposure, early findings among ZIKV-exposed children without CZS ages 0-5 years suggest that they may also have differences in multiple domains of neurodevelopment. Thus, longitudinal follow-up of all children with antenatal ZIKV exposure has been recommended. This review presents a summary of neurodevelopmental phenotypes of infants and children following antenatal ZIKV exposure. We present a multidimensional framework to understand child neurodevelopment from an interdisciplinary and whole-child perspective (International Classification of Functioning, Disability and Health model) and multi-domain ZIKV Outcome Toolboxes. The toolboxes are for clinicians, researchers, child educators, and others to implement longitudinal multi-domain neurodevelopmental assessments between ages 0-12 years. Recent innovations in telehealth and neuroimaging can help evaluate outcomes in ZIKV exposed children. The objective is to describe the multiple facets of neurodevelopmental focused care that can support the health, function, and well-being of children with antenatal ZIKV exposure. The research and clinical follow-up strategies are applicable to ZIKV and other congenital infectious or environmental exposures that can impact child neurodevelopment. IMPACT: International longitudinal cohort studies have revealed a range of differences in neurodevelopment among children with antenatal Zika virus (ZIKV) exposure. A multidimensional and whole-child framework is necessary to understand the neurodevelopment of children with antenatal ZIKV exposure in relation to family life, community participation, and environment. Multi-domain toolboxes that utilize parent questionnaires and child evaluations are presented. These toolboxes can be used internationally alongside telehealth, brain imaging, and other innovations to improve understanding of child outcomes.

Association between Sleep and Language Development in Children with Congenital Zika Syndrome

AIM

Congenital Zika Virus Syndrome (CZS) presents notable hurdles to neurodevelopment, with language development emerging as a crucial aspect. This study investigates sleep patterns and language skills in children with CZS, aiming to explore the potential synchronization of sleep development with their neurodevelopment.

METHOD

We studied cross-sectionally 135 children with CZS aged 0 to 48 months, investigating sleep using the BISQ Questionnaire. Language development was assessed using the Early Language Milestone Scale, while motor development and cognitive and social ability were assessed using the Bayley Scales of Infant and Young Child Development 3rd edition. We also studied longitudinally a cohort of 16 children (initially aged 0 to 12 months) whom we followed for four years, assessing at one-year intervals.

RESULTS

Sleep disturbances and language deficits were highly frequent in this population. In the 0-12 months group, a late bedtime and frequent nighttime awakenings were associated with poorer auditory expressive skills. At 13-24 months, nighttime awakenings were associated with poorer auditory expressive skills, while among 25-36-month-olds decreased auditory receptive skills were associated with longer sleep onset latency and reduced nighttime sleep duration.

CONCLUSION

The brain alterations caused by Zika virus infection affect both sleep disturbances and delays in language development. It is possible that sleep disturbance may be a mediating factor in the pathway between CZS and delayed language development, as the three analyzed language skills showed a correlation with sleep parameters.

Disruption of myelin structure and oligodendrocyte maturation in a macaque model of congenital Zika infection

Zika virus (ZikV) infection during pregnancy can cause congenital Zika syndrome (CZS) and neurodevelopmental delay in infants, of which the pathogenesis remains poorly understood. We utilize an established female pigtail macaque maternal-to-fetal ZikV infection/exposure model to study fetal brain pathophysiology of CZS manifesting from ZikV exposure in utero. We find prenatal ZikV exposure leads to profound disruption of fetal myelin, with extensive downregulation in gene expression for key components of oligodendrocyte maturation and myelin production. Immunohistochemical analyses reveal marked decreases in myelin basic protein intensity and myelinated fiber density in ZikV-exposed animals. At the ultrastructural level, the myelin sheath in ZikV-exposed animals shows multi-focal decompaction, occurring concomitant with dysregulation of oligodendrocyte gene expression and maturation. These findings define fetal neuropathological profiles of ZikV-linked brain injury underlying CZS resulting from ZikV exposure in utero. Because myelin is critical for cortical development, ZikV-related perturbations in oligodendrocyte function may have long-term consequences on childhood neurodevelopment, even in the absence of overt microcephaly.

Infectious Diseases and Basal Ganglia Calcifications: A Cross-Sectional Study in Patients with Fahr's Disease and Systematic Review

Background: It is unclear whether patients with basal ganglia calcifications (BGC) should undergo infectious disease testing as part of their diagnostic work-up. We investigated the occurrence of possibly associated infections in patients with BGC diagnosed with Fahr's disease or syndrome and consecutively performed a systematic review of published infectious diseases associated with BGC. Methods: In a cross-sectional study, we evaluated infections in non-immunocompromised patients aged ≥ 18 years with BGC in the Netherlands, who were diagnosed with Fahr's disease or syndrome after an extensive multidisciplinary diagnostic work-up. Pathogens that were assessed included the following: Brucella sp., cytomegalovirus, human herpesvirus type 6/8, human immunodeficiency virus (HIV), Mycobacterium tuberculosis, rubella virus, and Toxoplasma gondii. Next, a systematic review was performed using MEDLINE and Embase (2002-2023). Results: The cross-sectional study included 54 patients (median age 65 years). We did not observe any possible related infections to the BGC in this population. Prior infection with Toxoplasma gondii occurred in 28%, and in 94%, IgG rubella antibodies were present. The positive tests were considered to be incidental findings by the multidisciplinary team since these infections are only associated with BGC when congenitally contracted and all patients presented with adult-onset symptoms. The systematic search yielded 47 articles, including 24 narrative reviews/textbooks and 23 original studies (11 case series, 6 cross-sectional and 4 cohort studies, and 2 systematic reviews). Most studies reported congenital infections associated with BGC (cytomegalovirus, HIV, rubella virus, Zika virus). Only two studies reported acquired pathogens (chronic active Epstein-Barr virus and Mycobacterium tuberculosis). The quality of evidence was low. Conclusions: In our cross-sectional study and systematic review, we found no convincing evidence that acquired infections are causing BGC in adults. Therefore, we argue against routine testing for infections in non-immunocompromised adults with BGC in Western countries.

Congenital infectious encephalopathies from the intrapartum period to postnatal life

Congenital infections are a common but often underrecognized cause of fetal brain abnormalities, as well as fetal-neonatal morbidity and mortality, that should be considered by all healthcare professionals providing neurological care to fetuses and newborns. Maternal infection with various pathogens (cytomegalovirus, Toxoplasmosis, Rubella virus, Parvovirus B19, lymphocytic choriomeningitis virus, syphilis, Zika virus, varicella zoster virus) during pregnancy can be transmitted to the developing fetus, which can cause multisystem dysfunction and destructive or malformative central nervous system lesions. These can be recognized on fetal and neonatal imaging, including ultrasound and MRI. Imaging and clinical features often overlap, but some distinguishing features can help identify specific pathogens and guide subsequent testing strategies. Some pathogens can be specifically treated, and others can be managed with targeted interventions or symptomatic therapy based on expected complications. Neurological and neurodevelopmental complications related to congenital infections vary widely and are likely driven by a combination of pathophysiologic factors, alone or in combination. These include direct invasion of the fetal central nervous system by pathogens, inflammation of the maternal-placental-fetal triad in response to infection, and long-term effects of immunogenic and epigenetic changes in the fetus in response to maternal-fetal infection. Congenital infections and their neurodevelopmental impacts should be seen as an issue of public health policy, given that infection and the associated complications disproportionately affect woman and children from low- and middle-income countries and those with lower socio-economic status in high-income countries. Congenital infections may be preventable and treatable, which can improve long-term neurodevelopmental outcomes in children.

A Zika virus protein expression screen in Drosophila to investigate targeted host pathways during development

In the past decade, Zika virus (ZIKV) emerged as a global public health concern. Although adult infections are typically mild, maternal infection can lead to adverse fetal outcomes. Understanding how ZIKV proteins disrupt development can provide insights into the molecular mechanisms of disease caused by this virus, which includes microcephaly. In this study, we generated a toolkit to ectopically express ZIKV proteins in vivo in Drosophila melanogaster in a tissue-specific manner using the GAL4/UAS system. We used this toolkit to identify phenotypes and potential host pathways targeted by the virus. Our work identified that expression of most ZIKV proteins caused scorable phenotypes, such as overall lethality, gross morphological defects, reduced brain size and neuronal function defects. We further used this system to identify strain-dependent phenotypes that may have contributed to the increased pathogenesis associated with the outbreak of ZIKV in the Americas in 2015. Our work demonstrates the use of Drosophila as an efficient in vivo model to rapidly decipher how pathogens cause disease and lays the groundwork for further molecular study of ZIKV pathogenesis in flies.

Zika virus restriction of host antioxidant response is mediated by intracellular NS1 and reveals its ability to upregulate Bach1 expression

Zika virus (ZIKV), has gained global attention due to its association with severe disorders, including microcephaly and congenital Zika syndrome. We investigated the role of ZIKV nonstructural protein 1 (NS1) in altering the host's antioxidant response. Using a stable cell line expressing NS1, we found that NS1 significantly reduced the expression of antioxidant-related genes, including heme oxygenase 1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), and sequestosome-1 (SQSTM1), which are regulated NRF2. Interestingly, this effect was attributed to increased expression of BACH1, a factor that competes with NRF2 for binding to certain antioxidant responsive elements (ARE). Thus, ZIKV NS1-mediated disruption of the antioxidant system is linked to BACH1 overexpression. These findings offer insights into ZIKV pathogenesis and suggest potential therapeutic strategies targeting the NRF2-BACH1 axis.

Morphological and functional cardiac alterations in children with congenital Zika syndrome and severe neurological deficits

INTRODUCTION

Zika virus infection during pregnancy causes fetal microcephaly and brain damage. Congenital Zika syndrome (CZS) is characterized by systemic involvement with diffuse muscle impairment, a high frequency of arthrogryposis, and microphthalmia. Cardiac impairment in CZS has rarely been evaluated. Our study assessed morphology and biventricular cardiac function in children with CZS and advanced neurological dysfunction.

METHODS

This cross-sectional study was conducted on 52 children with CZS (Zika group; ZG) and 25 healthy children (control group; CG) in Paraiba, Brazil. Clinical evaluation, electrocardiogram (EKG), and transthoracic echocardiogram (TTE) were performed on all children. Additionally, troponin I and natriuretic peptide type B (BNP) levels, the degree of cerebral palsy, and neuroimaging findings were assessed in the ZG group.

RESULTS

The median age of the study population was 5 years in both groups, and 40.4% (ZG) and 60% (CG) were female. The most prevalent electrocardiographic alteration was sinus arrhythmia in both the ZG (n = 9, 17.3%) and CG (n = 4, 16%). The morphological parameters adjusted for Z score were as follows: left ventricular (LV) end-diastolic diameter in ZG: -2.36 [-5.10, 2.63] vs. CG: -1.07 [-3.43, 0.61], p<0.001); ascending aorta (ZG: -0.09 [-2.08, 1.60] vs. CG: 0.43 [-1.47, 2.2], p = 0.021); basal diameter of the right ventricle (RV) (ZG: -2.34 [-4.90, 0.97] vs. CG: -0.96 [-2.21, 0.40], p<0.01); and pulmonary artery dimension (ZG: -2.13 [-5.99, 0.98] vs. CG: -0.24 [-2.53, 0.59], p<0.01). The ejection fractions (%) were 65.7 and 65.6 in the ZG and CG, respectively (p = 0.968). The left atrium volume indices (mL/m2) in the ZG and CG were 13.15 [6.80, 18.00] and 18.80 [5.90, 25.30] (p<0.01), respectively, and the right atrium volume indices (mL/m2) were 10.10 [4.90, 15.30] and 15.80 [4.10, 24.80] (p<0.01). The functional findings adjusted for Z score were as follows: lateral systolic excursion of the mitral annular plane (MAPSE) (ZG: 0.36 [-2.79, 4.71] vs. CG: 1.79 [-0.93, 4.5], p = 0.001); tricuspid annular plane systolic excursion (TAPSE) (ZG: -2.43 [-5.47, 5.09] vs. CG: 0.07 [-1.98, 3.64], p<0.001); and the S' of the RV (ZG: 1.20 [3.35, 2.90] vs. CG: -0.20 [-2.15, 1.50], p = 0.0121). No differences in biventricular strain measurements were observed between the groups. Troponin I and BNP levels were normal in in the ZG. Grade V cerebral palsy and subcortical calcification were found in 88.6% and 97.22% of children in the ZG group, respectively.

CONCLUSION

A reduction in cardiac dimensions and functional changes were found in CZS patients, based on the TAPSE, S' of the RV, and MAPSE, suggesting the importance of cardiac evaluation and follow-up in this group of patients.

Treatment with sofosbuvir attenuates the adverse neurodevelopmental consequences of Zika virus infection in infant rhesus macaques

Zika virus (ZIKV) infection during infancy in a rhesus macaque (RM) model negatively impacts brain development resulting in long-term behavioral alterations. The current study investigated whether postexposure prophylaxis could alleviate these negative neurodevelopmental consequences. Three RM infants received a 14-day course of sofosbuvir (SOF; 15 mg/kg p.o.) treatment starting at 3 days post-infection with a Puerto Rican strain of ZIKV (PRVABC59) and were then monitored longitudinally for one year. In contrast to ZIKV-infected infant RMs who did not receive SOF, postexposure SOF treatment mitigated the neurodevelopmental, behavioral and cognitive changes seen after postnatal ZIKV infection even while not accelerating viral clearance from the blood. These data suggest that antiviral treatment may help ameliorate some, but not all, of the neurodevelopmental abnormalities associated with early postnatal ZIKV infection.

Zika Virus affects neurobehavioral development, and causes oxidative stress associated to blood-brain barrier disruption in a rat model of congenital infection

Zika virus (ZIKV) is a mosquito-borne flavivirus associated with several neurodevelopmental outcomes after in utero infection. Here, we studied a congenital ZIKV infection model with immunocompetent Wistar rats, able to predict disabilities and that could pave the way for proposing new effective therapies. We identified neurodevelopmental milestones disabilities in congenital ZIKV animals. Also, on 22nd postnatal day (PND), blood-brain barrier (BBB) proteins disturbances were detected in the hippocampus with immunocontent reduction of β_Catenin, Occludin and Conexin-43. Besides, oxidative stress imbalance on hippocampus and cortex were identified, without neuronal reduction in these structures. In conclusion, even without pups' microcephaly-like phenotype, congenital ZIKV infection resulted in neurobehavioral dysfunction associated with BBB and oxidative stress disturbances in young rats. Therefore, our findings highlighted the multiple impact of the congenital ZIKV infection on the neurodevelopment, which reinforces the continuity of studies to understand the spectrum of this impairment and to provide support to future treatment development for patients affected by congenital ZIKV.

Does Intra-Uterine Exposure to the Zika Virus Increase Risks of Cognitive Delay at Preschool Ages? Findings from a Zika-Exposed Cohort from Grenada, West Indies

Maternal infection with Zika virus (ZIKV) is associated with a distinct pattern of birth defects, known as congenital Zika syndrome (CZS). In ZIKV-exposed children without CZS, it is often unclear whether they were protected from in utero infection and neurotropism. Early neurodevelopmental assessment is essential for detecting neurodevelopmental delays (NDDs) and prioritizing at-risk children for early intervention. We compared neurodevelopmental outcomes between ZIKV-exposed and unexposed children at 1, 3 and 4 years to assess exposure-associated NDD risk. A total of 384 mother-child dyads were enrolled during a period of active ZIKV transmission (2016-2017) in Grenada, West Indies. Exposure status was based on laboratory assessment of prenatal and postnatal maternal serum. Neurodevelopment was assessed using the Oxford Neurodevelopment Assessment, the NEPSY® Second Edition and Cardiff Vision Tests, at 12 (n = 66), 36 (n = 58) and 48 (n = 59) months, respectively. There were no differences in NDD rates or vision scores between ZIKV-exposed and unexposed children. Rates of microcephaly at birth (0.88% vs. 0.83%, p = 0.81), and childhood stunting and wasting did not differ between groups. Our results show that Grenadian ZIKV-exposed children, the majority of whom were without microcephaly, had similar neurodevelopmental outcomes to unexposed controls up to at least an age of 4 years.

Visual findings in children exposed to Zika in utero in Nicaragua

Knowledge regarding the frequency of ocular abnormalities and abnormal visual function in children exposed to Zika virus (ZIKV) in utero but born without congenital Zika syndrome (CZS) is limited. We hypothesized that children exposed to ZIKV in utero born without CZS may have visual impairments in early childhood. We performed ophthalmic examination between 16 and 21 months of age and neurodevelopment assessment at 24 months of age with the Mullen Scales of Early Learning test (MSEL) on children enrolled in a cohort born to women pregnant during and shortly after the ZIKV epidemic in Nicaragua (2016-2017). ZIKV exposure status was defined based on maternal and infant serological testing. Visual impairment was defined as abnormal if the child had an abnormal ophthalmic exam and/or low visual reception score in the MSEL assessment. Of 124 children included in the analysis, 24 (19.4%) were classified as ZIKV-exposed and 100 (80.6%) unexposed according to maternal or cord blood serology. Ophthalmic examination showed that visual acuity did not differ significantly between groups, thus, 17.4% of ZIKV-exposed and 5.2% of unexposed had abnormal visual function (p = 0.07) and 12.5% of the ZIKV-exposed and 2% of the unexposed had abnormal contrast testing (p = 0.05). Low MSEL visual reception score was 3.2-fold higher in ZIKV-exposed than unexposed children, but not statistically significant (OR 3.2, CI: 0.8-14.0; p = 0.10). Visual impairment (a composite measure of visual function or low MESL visual reception score) was present in more ZIKV-exposed than in unexposed children (OR 3.7, CI: 1.2, 11.0; p = 0.02). However, the limited sample size warrants future investigations to fully assess the impact of in utero ZIKV exposure on ocular structures and visual function in early childhood, even in apparently healthy children.

A Zika virus protein expression screen in Drosophila to investigate targeted host pathways during development

In the past decade, Zika virus (ZIKV) emerged as a global public health concern. While adult infections are typically mild, maternal infection can lead to adverse fetal outcomes. Understanding how ZIKV proteins disrupt development can provide insights into the molecular mechanisms of symptoms caused by this virus including microcephaly. In this study, we generated a toolkit to ectopically express Zika viral proteins in vivo in Drosophila melanogaster in a tissue-specific manner using the GAL4/UAS system. We use this toolkit to identify phenotypes and host pathways targeted by the virus. Our work identified that expression of most ZIKV proteins cause scorable phenotypes, such as overall lethality, gross morphological defects, reduced brain size, and neuronal function defects. We further use this system to identify strain-dependent phenotypes that may contribute to the increased pathogenesis associated with the more recent outbreak of ZIKV in the Americas. Our work demonstrates Drosophila's use as an efficient in vivo model to rapidly decipher how pathogens cause disease and lays the groundwork for further molecular study of ZIKV pathogenesis in flies.

Prenatal and Postnatal Zika Intrauterine Infection: Diagnostic Imaging Techniques and Placental Pathology

Introduction: Zika virus (ZIKV) is an arbovirus (arthropod-borne virus) in the genus Flavivirus and Flaviviridae family. In November 2015, several cases of microcephaly in Northeastern of Brazil suggested ZIKV involvement. Case Report: A 33-year-old primigravida developed fever and cutaneous rash at 7th week of gestation (WGA). The ultrasound and MRI examination showed head circumference < 5th centile and enlargement of lateral ventricles. The infant was delivered at 39th WGA with microcephaly. Microscopy of the placenta showed chronic villitis and intervillitis, nodular stromal fibrosis in the stem villi, and vascular thickening. Postnatal CT showed collapsed cranium due to growth impairment of the suprathalamic brain, multiple cerebral calcifications, parenchymal atrophy, and ventricular dilatation. Now, at 6 years old, the child suffers from severe neurologic symptoms, including seizures. Conclusion: This case gathers images of prenatal and postnatal period, and placental histopathology. The long-term follow-up highlights the dramatic neurological sequelae induced by ZIKV.

Fetuses and infants with Amyoplasia congenita in congenital Zika syndrome: The evidence of a viral cause. A narrative review of 144 cases

OBJECTIVES

Amyoplasia congenita is the most frequent type of arthrogryposis causing fetal hypokinesia, leading to congenital contractures at birth. The pathogenesis is thought to be impaired blood circulation to the fetus early in pregnancy, with hypotension and hypoxia damaging the anterior horn cells. In animal studies however a prenatal infection with a poliomyelitis-like viral agent was demonstrated. Congenital Zika virus syndrome (CZVS) has recently been described in infants with severe microcephaly, and in 10-25% of cases arthrogryposis.

METHODS

A search in PubMed for CZVS yielded 124 studies. After a selection for arthrogryposis, 35 papers were included, describing 144 cases. The studies were divided into two categories. 1) Those (87 cases) focussing on imaging or histological data of congenital brain defects, contained insufficient information to link arthrogryposis specifically to lesions of the brain or spinal motor neuron. 2) In the other 57 cases detailed clinical data could be linked to neurophysiological, imaging or histological data.

RESULTS

In category 1 the most frequent brain abnormalities in imaging studies were ventriculomegaly, calcifications (subcortical, basal ganglia, cerebellum), hypoplasia of the brainstem and cerebellum, atrophy of the cerebral cortex, migration disorders and corpus callosum anomalies. In category 2, in 38 of 57 cases clinical data were indicative of Amyoplasia congenita. This diagnosis was confirmed by electromyographic findings (13 cases), by MRI (37 cases) or histology (12 cases) of the spinal cord. The latter showed small or absent lateral corticospinal tracts, and cell loss and degeneration of motor neuron cells. Zika virus-proteins and flavivirus-like particles were detected in cytoplasm of spinal neurons.

CONCLUSION

The phenotype of arthrogryposis in CZVS is consistent with Amyoplasia congenita. These findings warrant search for an intrauterine infection with any neurotropic viral agent with affinity to spinal motor neurons in neonates with Amyoplasia.

Would Zika virus Infection in Pregnancy Be a Sentence of Poor Neurological Prognosis for Exposed Children? Neurodevelopmental Outcomes in a Cohort from Brazilian Amazon

Infections with Flavivirus in pregnant women are not associated with vertical transmission. However, in 2015, severe cases of congenital infection were reported during the Zika virus outbreak in Brazil. More subtle infections in children born to mothers with ZIKV still remain uncertain and the spectrum of this new congenital syndrome is still under construction. This study describes outcomes regarding neurodevelopment and neurological examination in the first years of life, of a cohort of 77 children born to pregnant women with ZIKV infection in Manaus, Brazil, from 2017 to 2020. In the group of normocephalic children (92.2%), most showed satisfactory performance in neuropsychomotor development, with a delay in 29.6% and changes in neurological examination in 27.1%, with two children showing muscle-strength deficits. All microcephalic children (5.2%) evolved with severe neuropsychomotor-development delay, spastic tetraparesis, and alterations in the imaging exam. In this cohort, 10.5% of the children had macrocephaly at birth, but only 2.6% remained in this classification. Although microcephaly has been considered as the main marker of congenital-Zika-virus syndrome in previous studies, its absence does not exclude the possibility of the syndrome. This highlights the importance of clinical follow-up, regardless of the classification of head circumference at birth.

Characteristics of children of the Microcephaly Epidemic Research Group Pediatric Cohort who developed postnatal microcephaly

The number of studies published on postnatal microcephaly in children with Congenital Zika Syndrome is small, clinical presentations vary and aspects of the evolution of these children remain unclarified. The present case series examined clinical characteristics and assessed the growth velocity of the head circumference, weight and height Z-scores in 23 children who developed postnatal microcephaly during follow-up in the Microcephaly Epidemic Research Group Pediatric Cohort. To estimate the change in the head circumference, weight and height Z-scores over time and compare the mean difference between sexes, we used multilevel mixed-effects linear regressions with child-specific random effects. Among these children, 60.9% (n = 14/23) presented with craniofacial disproportion, 60.9% (n = 14/23) with strabismus, 47.8% (n = 11/23) with early onset seizures, 47.8% (n = 11/23) with dysphagia and 43.5% (n = 10/23) with arthrogryposis. Of the 82.7% (n = 19/23) children who underwent neuroimaging, 78.9% (n = 15/19) presented with alterations in the central nervous system. Monthly growth velocity, expressed in Z-scores, of the head circumference was − 0.098 (95% CI % − 0.117 to − 0.080), of weight was: − 0.010 (95%-CI − 0.033 to 0.014) and of height was: − 0.023 (95%-CI − 0.046 to 0.0001). Postnatal microcephaly occurred mainly in children who had already presented with signs of severe brain damage at birth; there was variability in weight and height development, with no set pattern.

Factors Associated with Behavioral Disorders in Children with Congenital Zika Syndrome and Their Families—A Cross-Sectional Study

The Zika virus was responsible for an outbreak between 2015 and 2016 in Brazil: an alarming public health problem of international relevance. The Congenital Zika Syndrome (CZS) is often associated with manifestations that are responsible for cognitive and motor development delays and behavioral disorders. Thus, we aimed to characterize the clinical-epidemiological and familial context of those children and to identify factors associated with the risk of behavioral disorders using the Survey of Well-Being of Young Children questionnaire (SWYC). In total, 52 children diagnosed with CZS were evaluated. Logistic regressions were employed to assess predictive variables for behavioral alteration. Eighteen (35%) of the children presented a risk of behavioral alteration. Children born normocephalic were 36-fold more likely to present behavioral alteration (95% CI: 3.82 to 337.92, p = 0.002). Children with hearing and visual impairments showed reduced risks. In total, 35% percent of families reported food insecurity and 21% were at risk for maternal depression. Our findings suggest better social interactions and conditions to externalize reactions for children with CZS born normocephalic. The continuous assessment of these children and families may identify conditions associated with behavioral alteration and psychosocial vulnerabilities that help in decision-making, therefore optimizing patient–family interactions.

Early Childhood Neurodevelopmental Outcomes in Children with Prenatal Zika Virus Exposure: A Cohort Study in Puerto Rico

OBJECTIVE

To describe anthropometric, sensory, and neurodevelopmental outcomes of children who were Zika virus-exposed from birth to 36 months.

STUDY DESIGN

The study cohort included 114 children born to mothers with confirmed and probable Zika virus pregnancy infection in 2016-2017. Children attending study visits from May 2017 through February 2020 underwent physical/neurologic, sensory examinations, and neurodevelopmental assessments with the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) and Ages and Stages Questionnaires, Third Edition (ASQ-3).

RESULTS

Three of the 114 children (2.6%) had microcephaly (z-score for head circumference ≤-2) at birth, 19 of 35 (54.3%) had posterior eye abnormalities in retinal images, and 11 of 109 (10.1%) had nonspecific findings on brain ultrasound. Three of 107 children (2.8%) failed hearing screening at birth. Of those children with follow-up data, 17 of 97 (17.5%) failed age-appropriate vision screening. The BSID-III identified developmental delay in at least 1 domain in at least one-third of children, with higher prevalence in the language domain. ASQ-3 screen positive delay peaked at around 24 or 36 months, with some domains showing a decrease at older ages. Correlations among BSID-III and ASQ-3 scores were observed, representing professional and parental perspectives at 24 and 36 months (r = 0.32-0.78; P < .05).

CONCLUSIONS

The presence of neurodevelopmental sequelae in early childhood suggests that identification of long-term impairment remains critical to attaining optimal child development. Long-term follow-up highlights vulnerability in the language domain, which likely could be influenced by early intervention, promoting cognitive development and school readiness in exposed children.

New Insights into Zika in Infants and Children

In the original article [...].

Neurodevelopment in Normocephalic Children Exposed to Zika Virus in Utero with No Observable Defects at Birth: A Systematic Review with Meta-Analysis

Zika virus (ZIKV) infection during pregnancy is a cause of pregnancy loss and multiple clinical and neurological anomalies in children. This systematic review aimed to assess the effect of ZIKV exposure in utero on the long-term neurodevelopment of normocephalic children born to women with ZIKV infection in pregnancy. This review was conducted according to the PRISMA guidelines for systematic reviews and meta-analyses. We performed a random effects meta-analysis to estimate the cross-study prevalence of neurodevelopmental delays in children using the Bayley Scales for Infant and Toddler Development (BSID-III). The risk of bias was assessed using Cochrane’s Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Full-text reviews were performed for 566 articles, and data were extracted from 22 articles corresponding to 20 studies. Nine articles including data from 476 children found 6.5% (95% CI: 4.1–9.3) of infants and children to have any type of non-language cognitive delay; 29.7% (95% CI: 21.7–38.2) to have language delay; and 11.5% (95% CI: 4.8–20.1) to have any type of motor delay. The pooled estimates had a high level of heterogeneity; thus, results should be interpreted with caution. Larger prospective studies that include a non-exposed control group are needed to confirm whether ZIKV exposure in utero is associated with adverse child neurodevelopmental outcomes.

Longitudinal Follow-Up of Gross Motor Function in Children with Congenital Zika Virus Syndrome from a Cohort in Rio de Janeiro, Brazil

Knowledge of how congenital Zika syndrome (CZS) impacts motor development of children longitudinally is important to guide management. The objective of the present study was to describe the evolution of gross motor function in children with CZS in a Rio de Janeiro hospital. In children with CZS without arthrogryposis or other congenital osteoarticular malformations who were followed in a prospective cohort study, motor performance was evaluated at two timepoints using the Gross Motor Function Classification System (GMFCS) and the Gross Motor Function Measurement test (GMFM-88). Among 74 children, at the baseline evaluation, the median age was 13 (8–24) months, and on follow-up, 28 (24–48) months. According to GMFCS at the second timepoint, 6 children were classified as mild, 11 as moderate, and 57 as severe. In the GMFM-88 assessment, children in the severe group had a median score of 10.05 in the baseline evaluation and a follow-up score of 12.40, the moderate group had median scores of 25.60 and 29.60, and the mild group had median scores of 82.60 and 91.00, respectively. Although a small developmental improvement was observed, the motor impairment of children was mainly consistent with severe cerebral palsy. Baseline motor function assessments were predictive of prognosis.

Zika virus congenital microcephaly severity classification and the association of severity with neuropsychomotor development

BACKGROUND

Zika virus infection during pregnancy is linked to birth defects, most notably microcephaly, which is associated with neurodevelopmental delays.

OBJECTIVE

The goals of the study were to propose a method for severity classification of congenital microcephaly based on neuroradiologic findings of MRI scans, and to investigate the association of severity with neuropsychomotor developmental scores. We also propose a semi-automated method for MRI-based severity classification of microcephaly.

MATERIALS AND METHODS

We conducted a cross-sectional investigation of 42 infants born with congenital Zika infection. Bayley Scales of Infant and Toddler Development III (Bayley-III) developmental evaluations and MRI scans were carried out at ages 13-39 months (mean: 24.8 months; standard deviation [SD]: 5.8 months). The severity score was generated based on neuroradiologist evaluations of brain malformations. Next, we established a distribution of Zika virus-microcephaly severity score including mild, moderate and severe and investigated the association of severity with neuropsychomotor developmental scores. Finally, we propose a simplified semi-automated procedure for estimating the severity score based only on volumetric measures.

RESULTS

The results showed a correlation of r=0.89 (P<0.001) between the Zika virus-microcephaly severity score and the semi-automated method. The trimester of infection did not correlate with the semi-automated method. Neuropsychomotor development correlated with the severity classification based on the radiologic readings and semi-automated method; the more severe the imaging scores, the lower the neuropsychomotor developmental scores.

CONCLUSION

These severity classification methods can be used to evaluate severity of microcephaly and possible association with developmental consequences. The semi-automated methods thus provide an alternative for predicting severity of microcephaly based on only one MRI sequence.

Neurodevelopment in Children Exposed to Zika in utero: Clinical and Molecular Aspects

Five years after the identification of Zika virus as a human teratogen, we reviewed the early clinical manifestations, collectively called congenital Zika syndrome (CZS). Children with CZS have a very poor prognosis with extremely low performance in motor, cognitive, and language development domains, and practically all feature severe forms of cerebral palsy. However, these manifestations are the tip of the iceberg, with some children presenting milder forms of deficits. Additionally, neurodevelopment can be in the normal range in the majority of the non-microcephalic children born without brain or eye abnormalities. Vertical transmission and the resulting disruption in development of the brain are much less frequent when maternal infection occurs in the second half of the pregnancy. Experimental studies have alerted to the possibility of other behavioral outcomes both in prenatally infected children and in postnatal and adult infections. Cofactors play a vital role in the development of CZS and involve genetic, environmental, nutritional, and social determinants leading to the asymmetric distribution of cases. Some of these social variables also limit access to multidisciplinary professional treatment.

Neuroanatomical abnormalities in a nonhuman primate model of congenital Zika virus infection

We evaluated neuropathological consequences of fetal ZIKV exposure in rhesus monkeys, a translatable animal model for human neural development, by carrying out quantitative neuroanatomical analyses of the nearly full-term brains of fetuses infected with ZIKV and procedure-matched controls. For each animal, a complete cerebral hemisphere was evaluated using immunohistochemical (IHC) and neuroanatomical techniques to detect virus, identify affected cell types, and evaluate gross neuroanatomical abnormalities. IHC staining revealed the presence of ZIKV in the frontal lobe, which contained activated microglia and showed increased apoptosis of immature neurons. ZIKV-infected animals exhibited macrostructural changes within the visual pathway. Regional differences tracked with the developmental timing of the brain, suggesting inflammatory processes related to viral infiltration swept through the cortex, followed by a wave of cell death resulting in morphological changes. These findings may help explain why some infants born with normal sized heads during the ZIKV epidemic manifest developmental challenges as they age.

Neurodevelopment in normocephalic children with and without prenatal Zika virus exposure

OBJECTIVE

Zika virus (ZIKV) targets neural stem cells in the developing brain. However, the majority of ZIKV-exposed children are born without apparent neurological manifestations. It remains unclear if these children were protected from ZIKV neurotropism or if they harbour subtle pathology that is disruptive to brain development. We assess this by comparing neurodevelopmental outcomes in normocephalic ZIKV-exposed children relative to a parallel control group of unexposed controls.

DESIGN

Cohort study.

SETTING

Public health centres in Grenada, West Indies.

PATIENTS

384 mother-child pairs were enrolled during a period of active ZIKV transmission (April 2016-March 2017) and prospectively followed up to 30 months. Child exposure status was based on laboratory assessment of prenatal and postnatal maternal serum.

MAIN OUTCOME MEASURES

The INTERGROWTH-21st Neurodevelopment Assessment (INTER-NDA) package and Cardiff Vision Tests, administered and scored by research staff masked to child's exposure status.

RESULTS

A total of 131 normocephalic ZIKV exposed (n=68) and unexposed (n=63) children were assessed between 22 and 30 months of age. Approximately half of these children completed vision testing. There were no group differences in sociodemographics. Deficits in visual acuity (31%) and contrast sensitivity (23%) were apparent in the ZIKV-exposed infants in the absence of cognitive, motor, language or behavioural delays.

CONCLUSIONS

Overall neurodevelopment is likely to be unaffected in ZIKV-exposed children with normal head circumference at birth and normal head growth in the first 2 years of life. However, the visual system may be selectively vulnerable, which indicates the need for vision testing by 3 years of age.

Two-year follow-up of children with congenital Zika syndrome: the evolution of clinical patterns

The aim of the study was to describe neurological manifestations in children with congenital Zika syndrome (CZS) in the first 2 years of age. In this prospective observational study, children with CZS treated at a university hospital received a neurological assessment and were evaluated using two neurodevelopmental scales (the Denver II test and the assessment of gross motor development of the World Health Organization) by a pediatric neurologist on admission to the study and at 4, 8, 12, 18, and 24 months of age. The data collected were stored in Microsoft Excel version 14.6.3. Thirty-eight children (27 males and 11 females; a median age of 4.3 months (interquartile range (IQR): 1.6-11.4)) with CZS were evaluated. Irritability was present in 50% and 27% of the children at 8 months and 24 months, respectively. Axial hypertonia was highly prevalent at 4 months (77%), with a decrease to 50% at 24 months. At all ages, spastic tetraparesis was the most common motor abnormality (> 80%). Twenty-seven (71%) participants were diagnosed with epilepsy, and the median age at seizure onset was 6 months (IQR: 3.5-8). The most frequent types of seizures were focal seizures and spasms, with spasms being the most frequent in the first year of life (52%) and focal crises being the most frequent in the second year of life (50%).Conclusion: This study allowed observation of neurological abnormalities over time, the evolution of epileptic manifestations, and recognition of new patterns of clinical neurological abnormalities, helping clinicians to recognize CZS earlier, minimizing the impact of new outbreaks. What is Known: • Clinical patterns of SZC patients at pre-established ages or date of data collection • More frequent studies with data collection of clinical-radiological features of patient's over his first year of life What is New: • Comprehensive clinical neurological progression data regarding CZS in the first 2 years of life, recognizing patterns • Hypothesis including a new CZS spectrum with milder clinical-radiological features.

Neurocognitive impact of Zika virus infection in adult rhesus macaques

Background

Zika virus (ZIKV) is a mosquito-transmitted flavivirus that affects many regions of the world. Infection, in utero, causes microcephaly and later developmental and neurologic impairments. The impact of ZIKV infection on neurocognition in adults has not been well described. The objective of the study was to assess the neurocognitive impact of ZIKV infection in adult rhesus macaques.

Methods

Neurocognitive assessments were performed using the Cambridge Neuropsychological Test Automated Battery (CANTAB) via a touch screen and modified Brinkman Board before and after subcutaneous ZIKV inoculation. Immune activation markers were measured in the blood and cerebral spinal fluid (CSF) by multiplex assay and flow cytometry.

Results

All animals (N = 8) had detectable ZIKV RNA in plasma at day 1 post-inoculation (PI) that peaked at day 2 PI (median 5.9, IQR 5.6–6.2 log₁₀ genome equivalents/mL). In all eight animals, ZIKV RNA became undetectable in plasma by day 14 PI, but persisted in lymphoid tissues. ZIKV RNA was not detected in the CSF supernatant at days 4, 8, 14 and 28 PI but was detected in the brain of 2 animals at days 8 and 28 PI. Elevations in markers of immune activation in the blood and CSF were accompanied by a reduction in accuracy and reaction speed on the CANTAB in the majority of animals.

Conclusions

The co-occurrence of systemic and CSF immune perturbations and neurocognitive impairment establishes this model as useful for studying the impact of neuroinflammation on neurobehavior in rhesus macaques, as it pertains to ZIKV infection and potentially other pathogens.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02402-4.

In Utero Exposure to Zika Virus Results in sex-Specific Memory Deficits and Neurological Alterations in Adult Mice

SUMMARY STATEMENT

In utero exposure to ZIKV leads to decreased number of neurons in adult mice. Female mice exposed to ZIKV in utero exhibit lower levels of BDNF, a decrease in synaptic markers, memory deficits, and risk-taking behavior during adulthood.

ADAR Editing in Viruses: An Evolutionary Force to Reckon with

Adenosine Deaminases that Act on RNA (ADARs) are RNA editing enzymes that play a dynamic and nuanced role in regulating transcriptome and proteome diversity. This editing can be highly selective, affecting a specific site within a transcript, or nonselective, resulting in hyperediting. ADAR editing is important for regulating neural functions and autoimmunity, and has a key role in the innate immune response to viral infections, where editing can have a range of pro- or antiviral effects and can contribute to viral evolution. Here we examine the role of ADAR editing across a broad range of viral groups. We propose that the effect of ADAR editing on viral replication, whether pro- or antiviral, is better viewed as an axis rather than a binary, and that the specific position of a given virus on this axis is highly dependent on virus- and host-specific factors, and can change over the course of infection. However, more research needs to be devoted to understanding these dynamic factors and how they affect virus-ADAR interactions and viral evolution. Another area that warrants significant attention is the effect of virus-ADAR interactions on host-ADAR interactions, particularly in light of the crucial role of ADAR in regulating neural functions. Answering these questions will be essential to developing our understanding of the relationship between ADAR editing and viral infection. In turn, this will further our understanding of the effects of viruses such as SARS-CoV-2, as well as many others, and thereby influence our approach to treating these deadly diseases.

Clinical and neurodevelopmental outcomes based on brain imaging studies in a Colombian cohort of children with probable antenatal Zika virus exposure

BACKGROUND

Our aim was to describe the neuroimaging and clinical evaluations of children with antenatal Zika-virus (ZIKV) exposure.

METHODS

The Colombian National Institute of Health performed serial clinical evaluations of children with probable antenatal ZIKV exposure (i.e., born to ZIKV symptomatic mothers or born with birth defects compatible with ZIKV infection, regardless of laboratory results) over 2 years that included head circumference (HC), eye examination, and neurodevelopmental assessments. Clinical neuroimaging studies (head computed tomography and/or brain magnetic resonance imaging) were analyzed for abnormalities, two-dimensional measurements were made of the right and left frontal and occipital cortical thickness. Two abnormal patterns were defined: Pattern 1 (sum of four areas of cortex <6 cm) and Pattern 2 (sum of four areas of cortex ≥6 cm and < 10 cm).

RESULTS

Thirty-one children had a neuroimaging study; in 24, cortical thickness was measured. The median age at the first visit was 8 (range: 6-9) months and 22 (range: 19-42) months at the last evaluation. In the 24 cases with cortical measurements, three were normal, 12 were in Pattern 1, and nine were in Pattern 2. Children within Pattern 1 had lower mean HC at birth and in follow-up (both p < .05) and a higher frequency of structural eye abnormalities (p < .01). A trend towards poorer neuromotor development was seen in Pattern 1, although not statistically significant (p = .06).

CONCLUSION

Brain imaging classification based on cortical measurements correlate with ophthalmologic abnormalities and HC. Cortical thickness may be a marker for clinical outcomes in children with congenital ZIKV infection.

The Term Newborn: Congenital Infections

Maternal pathogens can be transmitted to the fetus resulting in congenital infection with sequelae ranging from asymptomatic infection to severe debilitating disease and still birth. The TORCH pneumonic (toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus) is used widely, but it provides a limited description of the expanding list of pathogens associated with congenital infection. This article focuses on the evaluation and management of infants with common congenital infections such as cytomegalovirus, and infections that warrant early diagnosis and treatment to prevent serious complications, such as toxoplasmosis, human immunodeficiency virus, and syphilis. Zika virus and Chagas disease remain uncommon.

Non-human Primate Models to Investigate Mechanisms of Infection-Associated Fetal and Pediatric Injury, Teratogenesis and Stillbirth

A wide array of pathogens has the potential to injure the fetus and induce teratogenesis, the process by which mutations in fetal somatic cells lead to congenital malformations. Rubella virus was the first infectious disease to be linked to congenital malformations due to an infection in pregnancy, which can include congenital cataracts, microcephaly, hearing impairment and congenital heart disease. Currently, human cytomegalovirus (HCMV) is the leading infectious cause of congenital malformations globally, affecting 1 in every 200 infants. However, our knowledge of teratogenic viruses and pathogens is far from complete. New emerging infectious diseases may induce teratogenesis, similar to Zika virus (ZIKV) that caused a global pandemic in 2016-2017; thousands of neonates were born with congenital microcephaly due to ZIKV exposure in utero, which also included a spectrum of injuries to the brain, eyes and spinal cord. In addition to congenital anomalies, permanent injury to fetal and neonatal organs, preterm birth, stillbirth and spontaneous abortion are known consequences of a broader group of infectious diseases including group B streptococcus (GBS), Listeria monocytogenes, Influenza A virus (IAV), and Human Immunodeficiency Virus (HIV). Animal models are crucial for determining the mechanism of how these various infectious diseases induce teratogenesis or organ injury, as well as testing novel therapeutics for fetal or neonatal protection. Other mammalian models differ in many respects from human pregnancy including placentation, labor physiology, reproductive tract anatomy, timeline of fetal development and reproductive toxicology. In contrast, non-human primates (NHP) most closely resemble human pregnancy and exhibit key similarities that make them ideal for research to discover the mechanisms of injury and for testing vaccines and therapeutics to prevent teratogenesis, fetal and neonatal injury and adverse pregnancy outcomes (e.g., stillbirth or spontaneous abortion). In this review, we emphasize key contributions of the NHP model pre-clinical research for ZIKV, HCMV, HIV, IAV, L. monocytogenes, Ureaplasma species, and GBS. This work represents the foundation for development and testing of preventative and therapeutic strategies to inhibit infectious injury of human fetuses and neonates.

Long-Term Outcomes of Infants with Congenital Zika Virus Infection in Ecuador: A Retrospective Longitudinal Study

BACKGROUND

Few congenital Zika syndrome (CZS) cases have been notified in Ecuador and, to our knowledge, there are no significant published studies dealing with their clinical evolution. We present a detailed clinical characterization of 21 children with congenital Zika virus (ZIKV) infection born in Ecuador who were followed up until September 2019.

METHODS

We did a retrospective longitudinal study of children attended by the infectious disease specialists of Francisco Icaza Bustamante Children's Hospital (Guayaquil) due to congenital ZIKV infection suspicion. The inclusion criteria consisted of laboratory confirmed diagnosis of congenital ZIKV infection.

RESULTS

Sixteen of these 21 cases of congenital ZIKV infection showed clinical, neuroimaging and laboratory findings strongly suggestive of CZS and 5 children showed laboratory findings compatible with congenital ZIKV infection without congenital manifestations associated to CZS. All children with CZS showed neurodevelopmental delay, spasticity and hyperreflexia during follow-up, whereas the majority of them (14/15) experienced recurrent epileptic seizures and dysphagia (12/13). Two CZS cases died during follow-up. Visual evoked potential and hearing screening with acoustically evoked auditory brainstem response were abnormal in 50% and 37.5% of CZS cases, respectively. Congenital ZIKV infection without findings consistent with CZS at birth was not clinically relevant at 23 months of age in the five cases of our cohort.

CONCLUSIONS

Severe neurodevelopmental delay, severe microcephaly, epileptic seizures and dysphagia were present at 2 years of age in most CZS cases of our cohort.

Cranial US in Infants Exposed to Zika Virus: The NATZIG Cohort

Background Studies addressing neuroimaging findings as primary outcomes of congenital Zika virus infection are variable regarding inclusion criteria and confirmatory laboratory testing. Purpose To investigate cranial US signs of prenatal Zika virus exposure and to describe frequencies of cranial US findings in infants exposed to Zika virus compared to those in control infants. Materials and Methods In this single-center prospective cohort study, participants were enrolled during the December 2015-July 2016 outbreak of Zika virus infection in southeast Brazil (Natural History of Zika Virus Infection in Gestation cohort). Eligibility criteria were available cranial US and laboratory findings of maternal Zika virus infection during pregnancy confirmed with RNA polymerase chain reaction testing (ie, Zika virus-exposed infants). The control group was derived from the Zika in Infants and Pregnancy cohort and consisted of infants born to asymptomatic pregnant women who tested negative for Zika virus infection during pregnancy. Two radiologists who were blinded to the maternal Zika virus infection status independently reviewed cranial US scans from both groups and categorized them as normal findings, Zika virus-like pattern, or mild findings. Associations between cranial US findings and prenatal Zika virus exposure were assessed with univariable analysis. Results Two hundred twenty Zika virus-exposed infants (mean age, 53.3 days ± 71.1 [standard deviation]; 113 boys) and born to 219 mothers infected with Zika virus were included in this study and compared with 170 control infants (mean age, 45.6 days ± 45.8; 102 boys). Eleven of the 220 Zika virus-exposed infants (5%), but no control infants, had a Zika virus-like pattern at cranial US. No difference in frequency of mild findings was observed between the groups (50 of 220 infants [23%] vs 44 of 170 infants [26%], respectively; P = .35). The mild finding of lenticulostriate vasculopathy, however, was nine times more frequent in Zika virus-exposed infants (12 of 220 infants, 6%) than in control infants (one of 170 infants, 1%) (P = .01). Conclusion Lenticulostriate vasculopathy was more common after prenatal exposure to Zika virus, even in infants with normal head size, despite otherwise overall similar frequency of mild cranial US findings in Zika virus-exposed infants and in control infants. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Benson in this issue.

Characterization of adult patients with Guillain-Barré syndrome during the arboviral infection outbreaks in Honduras

Arbovirus infections have been associated with a wide spectrum of neurological manifestations. Among these, Guillain-Barré syndrome (GBS) is one of the most common. This study describes the characteristics of GBS associated with arbovirus infections during the outbreak which occurred in Honduras from January 2016 to February 2019. This was an observational retrospective study of adult patients who were diagnosed with GBS during that time. The diagnosis of GBS was based upon the criteria first published by Asbury, et al. and subsequently revised as the Brighton Criteria. A total of 91 patients with GBS constituted the study population. RT-PCR tests for ZIKV, CHIKV, and DENV arboviruses were performed in 47 (52%) of the patients. Of the tested population, 8/47 were positive for one of the arboviruses (5/8 for ZIKV, 3/8 for CHIKV; 0/8 for DENV). The clinical profile of the eight cases with GBS and arboviral infection did not differ significantly from the GBS patients who tested negative for ZIKV and CHIKV. In the cases with GBS and ZIKV, a parainfectious onset of the disease was suggested. Although not a strikingly large number of patients with GBS and arbovirus infection were seen, the close temporal relationship in these eight cases suggests an arbovirus (ZIKV and CHIKV) etiology.

Machine learning model on heart rate variability metrics identifies asymptomatic toddlers exposed to zika virus during pregnancy

Objective. Although the Zika virus (ZIKV) seems to be prominently neurotropic, there are some reports of involvement of other organs, particularly the heart. Of special concern are those children exposed prenatally to ZIKV and born without microcephaly or other congenital anomalies. Electrocardiogram (ECG)-derived heart rate variability (HRV) metrics represent an attractive, low-cost, widely deployable tool for early identification of developmental functional alterations in exposed children born without such overt clinical symptoms. We hypothesized that HRV in such children would yield a biomarker of fetal ZIKV exposure. Our objective was to test this hypothesis in young children exposed to ZIKV during pregnancy.Approach. We investigated the HRV properties of 21 children aged 4-25 months from Brazil. The infants were divided into two groups, the ZIKV-exposed (n = 13) and controls (n = 8). Single-channel ECG was recorded in each child at ∼15 months of age and HRV was analyzed in 5 min segments to provide a comprehensive characterization of the degree of variability and complexity of the heart rate.Main results.Using a cubic support vector machine classifier we identified babies as Zika cases or controls with a negative predictive value of 92% and a positive predictive value of 86%. Our results show that a machine learning model derived from HRV metrics can help differentiate between ZIKV-affected, yet asymptomatic, and non-ZIKV-exposed babies. We identified the box count as the best HRV metric in this study allowing such differentiation, regardless of the presence of microcephaly.Significance.We show that it is feasible to measure HRV in infants and toddlers using a small non-invasive portable ECG device and that such an approach may uncover the memory ofin uteroexposure to ZIKV. We discuss putative mechanisms. This approach may be useful for future studies and low-cost screening tools involving this challenging to examine population.

Placental Morphologic Similarities Between ZIKV-Positive and HIV-Positive Pregnant Women

Zika virus (ZIKV) caused global concern due to Brazil's unexpected epidemic, and it was associated with congenital microcephaly and other gestational intercurrences. The study aimed to analyze the placenta morphometric changes of ZIKV-infected pregnant women (ZIKV group; n = 23) compared to placentas of HIV-infected (HIV group; n = 24) and healthy pregnant women (N-control group; n = 22). It also analyzed the relationship between the morphometric results and pathological alterations on conventional microscopy, gestational trimester of infection, and presence of the congenital Zika syndrome (CZS). There was a significant increase in area (p = 0.0172), as well as a higher number of knots (p = 0.0027), sprouts (p < 0.0001), and CD163 +Hofbauer cells (HCs) (p < 0.0001) in the ZIKV group compared to the N-control group, suggesting that villous dysmaturity and HCs hyperplasia could be associated with ZIKV infections. The HIV group had a higher area (p < 0.0001), perimeter (p = 0.0001), sprouts (p < 0.0001), and CD163 + HCs (p < 0.0001) compared to the N-control group, demonstrating that the morphometric abnormalities found in the ZIKV and HIV group are probably similar. However, when ZIKV and HIV groups are compared, it was observed a higher number of sprouts (p = 0.0066) and CD163+ HCs (p < 0.0001) in the first one, suggesting that placental ZIKV congenital changes could be more pronounced.

Physical Growth and Neurodevelopment of a Cohort of Children after 3.5 Years of Follow-up from Mothers with Zika Infection during Pregnancy-Third Report of the ZIKERNCOL Study

INTRODUCTION

In utero Zika virus (ZIKV) exposure has been related to a group of congenital structural abnormalities called the congenital Zika syndrome, which also has been related to neurodevelopment alterations even in normocephalic children. Physical growth has been less explored, and delayed growth and malnutrition have been reported.

OBJECTIVE

The objective of this study is to describe the growth and neurodevelopment features of normocephalic infants born from a cohort of mothers with RT-PCR confirmed ZIKV during pregnancy in Risaralda, Colombia.

METHODS

We conducted a retrospective cohort, including normocephalic children born from mothers with RT-PCR confirmed ZIKV infection during pregnancy in Risaralda, Colombia. Physical growth was measured using WHO standards, and neurodevelopment was measured with the abbreviated neurodevelopment scale 2 validated for Colombia.

RESULTS

After verifying inclusion and exclusion criteria, 16 children were followed during a median time of 28 months (IQR 23-31 months); for a total of 116 visits, 87.5% (n = 14) of the patients developed a growth alteration. Five presented post-natal microcephaly, and among them, four presented malnutrition or low height. Six patients developed macrocephaly. Patients with a normal head circumference had normal neurodevelopment. Only one patient with microcephaly persisted with impairment of the neurodevelopment at the end of follow-up. All the patients with macrocephaly had normal neurodevelopment.

DISCUSSION

Our study suggests that growth could be altered in infants with in utero Zika exposure. We found a high proportion of patients with overgrowth and macrocephaly. Future studies should consider endocrine follow-up of children born with in utero Zika exposure to explore these findings' possible aetiologies.

CONCLUSION

We found a high proportion of growth alterations, particularly with overgrowth features and macrocephaly. Our study suggests that in addition to neurodevelopment impairment, growth could be altered in infants and children with in utero Zika exposure, even in those patients born without CZS.

Plasma lipidome profiling of newborns with antenatal exposure to Zika virus

The 2015–2016 Zika virus (ZIKV) outbreak in Brazil was remarkably linked to the incidence of microcephaly and other deleterious clinical manifestations, including eye abnormalities, in newborns. It is known that ZIKV targets the placenta, triggering an inflammatory profile that may cause placental insufficiency. Transplacental lipid transport is delicately regulated during pregnancy and deficiency on the delivery of lipids such as arachidonic and docosahexaenoic acids may lead to deficits in both brain and retina during fetal development. Here, plasma lipidome profiles of ZIKV exposed microcephalic and normocephalic newborns were compared to non-infected controls. Our results reveal major alterations in circulating lipids from both ZIKV exposed newborns with and without microcephaly relative to controls. In newborns with microcephaly, the plasma concentrations of hydroxyoctadecadienoic acid (HODE), primarily as 13-HODE isomer, derived from linoleic acid were higher as compared to normocephalic ZIKV exposed newborns and controls. Total HODE concentrations were also positively associated with levels of other oxidized lipids and several circulating free fatty acids in newborns, indicating a possible plasma lipidome signature of microcephaly. Moreover, higher concentrations of lysophosphatidylcholine in ZIKV exposed normocephalic newborns relative to controls suggest a potential disruption of polyunsaturated fatty acids transport across the blood-brain barrier of fetuses. The latter data is particularly important given the neurocognitive and neurodevelopmental abnormalities observed in follow-up studies involving children with antenatal ZIKV exposure, but normocephalic at birth. Taken together, our data reveal that plasma lipidome alterations associated with antenatal exposure to ZIKV could contribute to identification and monitoring of the wide spectrum of clinical phenotypes at birth and further, during childhood.

Antenatal exposure to Zika virus (ZIKV) is linked to a wide range of clinical presentations at birth, from asymptomatic cases to microcephaly, and other neurocognitive and neurodevelopmental abnormalities manifested in the early childhood. Stratification of these clinical phenotypes in newborns with suspected antenatal ZIKV exposure is challenging, but critical to improve early assessment of rehabilitative interventions. In this study, plasma lipidome profiling of 274 lipid species was performed in both normocephalic and microcephalic newborns with antenatal ZIKV exposure and compared to non-infected controls. Multiple lipid species were independent predictors of antenatal ZIKV exposure. More specifically, microcephaly was strongly associated with an oxidized free fatty acid and ZIKV exposed normocephalic newborns exhibited higher plasma concentrations of lysophosphatidylcholine relative to controls. These findings emphasize the need for studies focused on the role of individual lipids in neuropathogenesis of ZIKV and raise the potential of plasma lipidome profiling for early diagnosis of newborns with suspected antenatal ZIKV exposure. To validate the predictive ability of this approach, prospective studies with a larger cohort of newborns are now required.

Three-Year Clinical Follow-Up of Children Intrauterine Exposed to Zika Virus

Congenital Zika virus (ZIKV) infection may present with a broad spectrum of clinical manifestations. Some sequelae, particularly neurodevelopmental problems, may have a later onset. We conducted a prospective cohort study of 799 high-risk pregnant women who were followed up until delivery. Eighty-three women and/or newborns were considered ZIKV exposed and/or infected. Laboratory diagnosis was made by polymerase chain reaction in the pregnant mothers and their respective newborns, as well as Dengue virus, Chikungunya virus, and ZIKV serology. Serology for toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus, and syphilis infections were also performed in microcephalic newborns. The newborns included in the study were followed up until their third birthday. Developmental delay was observed in nine patients (13.2%): mild cognitive delay in three patients, speech delay in three patients, autism spectrum disorder in two patients, and severe neurological abnormalities in one microcephalic patient; sensorineural hearing loss, three patients and dysphagia, six patients. Microcephaly due to ZIKV occurred in three patients (3.6%). Clinical manifestations can appear after the first year of life in children infected/exposed to ZIKV, emphasizing the need for long-term follow-up.

Congenital Zika syndrome: Growth, clinical, and motor development outcomes up to 36 months of age and differences according to microcephaly at birth

BACKGROUND

Little is known regarding the developmental consequences of congenital Zika syndrome (CZS) without microcephaly at birth. Most previously published clinical series were descriptive and they had small sample sizes.

STUDY DESIGN

We conducted a cohort study to compare the growth, clinical, and motor development outcomes for 110 children with CZS born with and without microcephaly up to their third birthday. Ninety-three had their head circumference (HC) at birth abstracted and they did not have hypertensive hydrocephalus at birth, where 61 were born with microcephaly and 32 without.

RESULTS

The HC z-scores decreased steeply from birth to six months of age, i.e., from -3.77 to -6.39 among those with microcephaly at birth and from -1.03 to -3.84 among those without. Thus, at 6 months of age, the mean HC z-scores for children born without microcephaly were nearly the same as those for children born with microcephaly. Children born without microcephaly were less likely to have brain damage, ophthalmic abnormalities, and drug-resistant epilepsy, but the differences in many conditions were not statistically significant.

CONCLUSIONS

Children born without microcephaly were only slightly less likely to present severe neurologic impairment and to develop postnatal-onset microcephaly, and some of the original differences between the groups tended to dissipate with age.

Clinical and Preclinical Evidence for Adverse Neurodevelopment after Postnatal Zika Virus Infection

Although the Zika virus (ZIKV) typically causes mild or no symptoms in adults, during the 2015−2016 outbreak, ZIKV infection in pregnancy resulted in a spectrum of diseases in infants, including birth defects and neurodevelopmental disorders identified in childhood. While intense clinical and basic science research has focused on the neurodevelopmental outcomes of prenatal ZIKV infection, less is known about the consequences of infection during early life. Considering the neurotropism of ZIKV and the rapidly-developing postnatal brain, it is important to understand how infection during infancy may disrupt neurodevelopment. This paper reviews the current knowledge regarding early postnatal ZIKV infection. Emerging clinical evidence supports the hypothesis that ZIKV infection during infancy can result in negative neurologic consequences. However, clinical data regarding postnatal ZIKV infection in children are limited; as such, animal models play an important role in understanding the potential complications of ZIKV infection related to the vulnerable developing brain. Preclinical data provide insight into the potential behavioral, cognitive, and motor domains that clinical studies should examine in pediatric populations exposed to ZIKV during infancy.

Long-term persistence of infectious Zika virus: Inflammation and behavioral sequela in mice

The neurodevelopmental defects associated with ZIKV infections early in pregnancy are well documented, however the potential defects and long-term consequences associated with milder infections in late pregnancy and perinatal period are less well understood. To model these, we challenged 1 day old (P1) immunocompetent C57BL/6 mice with ZIKV. The animals developed a transient neurological syndrome including unsteady gait, kinetic tremors, severe ataxia and seizures 10-15 days post-infection (dpi) but symptoms subsided after a week, and most animals survived. Despite apparent recovery, MRI of convalescent mice show reduced cerebellar volume that correlates with altered coordination and motor function as well as hyperactivity and impulsivity. Persistent mRNA levels of pro-inflammatory genes including Cd80, Il-1α, and Ifn-γ together with Cd3, Cd8 and perforin (PrfA), suggested persistence of low-grade inflammation. Surprisingly, the brain parenchyma of convalescent mice harbor multiple small discrete foci with viral antigen, active apoptotic processes in neurons, and cellular infiltrates, surrounded by activated astrocytes and microglia as late as 1-year post-infection. Detection of negative-sense strand viral RNA and isolation of infectious virus derived from these convalescent mice by blinded passage in Vero cells confirmed long-term persistence of replicating ZIKV in CNS of convalescent mice. Although the infection appears to persist in defined reservoirs within CNS, the resulting inflammation could increase the risk of neurodegenerative disorders. This raises concern regarding possible long-term effects in asymptomatic children exposed to the virus and suggests that long-term neurological and behavioral monitoring as well as anti-viral treatment to clear virus from the CNS may be useful in patients exposed to ZIKV at an early age.

Epilepsy surveillance in normocephalic children with and without prenatal Zika virus exposure

Children with Congenital Zika Syndrome and microcephaly are at high risk for epilepsy; however, the risk is unclear in normocephalic children with prenatal Zika virus (ZIKV) exposure [Exposed Children (EC)]. In this prospective cohort study, we performed epilepsy screening in normocephalic EC alongside a parallel group of normocephalic unexposed children [Unexposed Children (UC)]. We compared the incidence rate of epilepsy among EC and UC at one year of life to global incidence rates. Pregnant women were recruited from public health centers during the ZIKV outbreak in Grenada, West Indies and assessed for prior ZIKV infection using a plasmonic-gold platform that measures IgG antibodies in serum. Normocephalic children born to mothers with positive ZIKV results during pregnancy were classified as EC and those born to mothers with negative ZIKV results during and after pregnancy were classified as UC. Epilepsy screening procedures included a pediatric epilepsy screening questionnaire and video electroencephalography (vEEG). vEEG was collected using a multi-channel microEEG® system for a minimum of 20 minutes along with video recording of participant behavior time-locked to the EEG. vEEGs were interpreted independently by two pediatric epileptologists, who were blinded to ZIKV status, via telemedicine platform. Positive screening cases were referred to a local pediatrician for an epilepsy diagnostic evaluation. Epilepsy screens were positive in 2/71 EC (IR: 0.028; 95% CI: 0.003-0.098) and 0/71 UC. In both epilepsy-positive cases, questionnaire responses and interictal vEEGs were consistent with focal, rather than generalized, seizures. Both children met criteria for a clinical diagnosis of epilepsy and good seizure control was achieved with carbamazepine. Our results indicate that epilepsy rates are modestly elevated in EC. Given our small sample size, results should be considered preliminary. They support the use of epilepsy screening procedures in larger epidemiological studies of children with congenital ZIKV exposure, even in the absence of microcephaly, and provide guidance for conducting epilepsy surveillance in resource limited settings.

Brain Iron Accumulation and the Formation of Calcifications After Developmental Zika Virus Infection

Intracranial calcifications (ICC) are the most common neuropathological finding in the brains of children exposed in utero to the Zika virus (ZIKV). Using a mouse model of developmental ZIKV infection, we reported widespread calcifications in the brains of susceptible mice that correlated in multiple ways with the behavioral deficits observed. Here, we examined the time course of ICC development and the role of iron deposition in this process, in 3 genetically distinct inbred strains of mice. Brain iron deposits were evident by Perls' staining at 2 weeks post infection, becoming increasingly dense and coinciding with calcium buildup and the formation of ICCs. A regional analysis of the brains of susceptible mice (C57BL/6J and 129S1/SvImJ strains) revealed the presence of iron initially in regions containing many ZIKV-immunoreactive cells, but then spreading to regions containing few infected cells, most notably the thalamus and the fasciculus retroflexus. Microglial activation was widespread initially and later delineated the sites of ICC formation. Behavioral tests conducted at 5-6 weeks of age revealed greater deficits in mice with the most extensive iron deposition and calcification of subcortical regions, such as thalamus. These findings point to iron deposition as a key factor in the development of ICCs after developmental ZIKV infection.

Focal epilepsy features in a child with Congenital Zika Syndrome

•

Congenital Zika Syndrome with microcephaly can present with focal seizures.

•

TeleEEG can augment epilepsy care in Zika-endemic resource limited settings.

•

A seizure questionnaire can prompt caregiver report of relevant seizure features.

Zika virus (ZIKV) is a mosquito-borne, single-stranded DNA flavivirus that is teratogenic and neurotropic. Similar to the teratogenic effects of other TORCH infections, ZIKV infection during pregnancy can have an adverse impact on fetal and neonatal development. Epilepsy is detected in 48–96% of children with Congenital Zika Syndrome (CZS) and microcephaly. Early epilepsy surveillance is needed in children with prenatal ZIKV exposure; yet, most ZIKV-endemic regions do not have specialist epilepsy care. Here, we describe the demographic, clinical, imaging, and EEG characteristics of a 2-year-old child with CZS and microcephaly who presented with focal epileptiform activity, suboptimal growth, and severe neurodevelopmental delays. Administration of a brief seizure questionnaire by allied health professionals to the patient’s caregiver helped to characterize the child’s seizure semiology and differentiate focal from generalized seizure features. A telemedicine EEG interpretation platform provided valuable diagnostic information for the patient’s local pediatrician to integrate into her treatment plan. This case illustrates that CZS can present with focal epilepsy features and that a telemedicine approach can be used to bridge the gap between epilepsy specialists and local care providers in resource limited ZIKV-endemic regions to achieve better seizure control in children with CZS.

Epilepsy after congenital zika virus infection: EEG and neuroimaging features

PURPOSE

To describe epilepsy after congenital Zika virus infection (ZIKV) and its relationship with structural neuroimaging findings.

METHODS

This was a cross-sectional study in children (aged 13-42 months) who were born with microcephaly due to ZIKV infection between 2015-2017. Patients underwent a brain imaging scan (magnetic resonance) and a video-EEG study.

RESULTS

Among the patients (n = 43), 55.8 % were male, 88.4 % were born at term, mean head circumference at the birth was 29.7 ± 1.8 cm, and 44.8 % were infected in the first trimester of pregnancy. Neuroimaging was moderately abnormal in 30.2 % and severely abnormal in 46.5 % of patients. Early seizures (<6 months of age) were observed in 41.9 %. EEG background was abnormal when asleep or awake in 72.1 % and during sleep in 62.8 %. The interictal epileptogenic activity was recorded on 41/43 of the EEGs and was predominantly multifocal (62.8 %). An ictal EEG was obtained in 22 patients and 31.8 % had more than one seizure type. Sleep EEG (background) patterns, interictal epileptogenic activity (p = 0.046), interictal discharge localization (p = 0.015), type of ictal epileptogenic activity (p = 0.002), and localization of ictal discharge (p = 0.024) were significantly different between neuroimaging groups. The mild neuroimaging group had a higher chance of having more frequently normal sleep EEG patterns, no interictal epileptogenic activity and a further increase in the probability of walking without limitations, and less neurodevelopment delay.

CONCLUSION

In patients with congenital Zika virus syndrome, epilepsy tended to be early and refractory. EEG features correlated with degree of neuroimaging abnormalities.

Cellular Imprinting Proteomics Assay: A Novel Method for Detection of Neural and Ocular Disorders Applied to Congenital Zika Virus Syndrome

Congenital Zika syndrome was first described due to increased incidence of congenital abnormalities associated with Zika virus (ZIKV) infection. Since the eye develops as part of the embryo central nervous system (CNS) structure, it becomes a specialized compartment able to display symptoms of neurodegenerative diseases and has been proposed as a noninvasive approach to the early diagnosis of neurological diseases. Ocular lesions result from defects that occurred during embryogenesis and can become apparent in newborns exposed to ZIKV. Furthermore, the absence of microcephaly cannot exclude the occurrence of ocular lesions and other CNS manifestations. Considering the need for surveillance of newborns and infants with possible congenital exposure, we developed a method termed cellular imprinting proteomic assay (CImPA) to evaluate the ocular surface proteome specific to infants exposed to ZIKV during gestation compared to nonexposure. CImPA combines surface cells and fluid capture using membrane disks and a large-scale quantitative proteomics approach, which allowed the first-time report of molecular alterations such as neutrophil degranulation, cell death signaling, ocular and neurological pathways, which are associated with ZIKV infection with and without the development of congenital Zika syndrome, CZS. Particularly, infants exposed to ZIKV during gestation and without early clinical symptoms could be detected using the CImPA method. Lastly, this methodology has broad applicability as it could be translated in the study of several neurological diseases to identify novel diagnostic biomarkers. Data are available via ProteomeXchange with identifier PXD014038.