The phenotypic spectrum of congenital Zika syndrome

From the Farm to the Lab: How Chicken Embryos Contribute to the Field of Teratology

Congenital anomalies and its causes, particularly, by external factors are the aim of the field called teratology. The external factors studied by teratology are known as teratogens and can be biological or environmental factors for example, chemicals, medications, recreational drugs, environmental pollutants, physical agents (e.g., X-rays and maternal hyperthermia) and maternal metabolic conditions. Proving the teratogenicity of a factor is a difficult task requiring epidemiology studies as well as experimental teratology evidence from the use of animal models, one of which is the chicken embryo. This model in particular has the advantage of being able to follow development live and in vivo, with rapid development hatching around 21 days, is cheap and easy to manipulate and to observe development. All this allows the chicken embryo to be used in drug screening studies, teratogenic evaluation and studies of mechanisms of teratogenicity. The chicken embryo shares morphological, biochemical and genetic similarities with humans as well as mammalian species, making them ideal to ascertain the actions of teratogens, as well as screen drugs to test for their safety. Pre-clinical trials for new drugs are carried out in rodents and rabbits, however, chicken embryos have been used to screen new compounds or analogs of thalidomide as well as to investigate how some drugs can lead to congenital malformations. Indeed, the chicken embryo has proved valuable in understanding how many congenital anomalies, seen in humans, arise following teratogen exposure. The aim of this review is to highlight the role of the chicken embryo as an experimental model for studies in teratology, exploring its use in drug screening studies, phenotypic evaluation and studies of teratogenic mechanisms of action. Here, we discuss many known teratogens, that have been evaluated using the chicken embryo model including some medicines, such as, thalidomide, valproic acid; recreational drugs including alcohol; environmental influences, such as viruses, specifically ZIKV, which is a newly discovered human teratogen. In addition, we discuss how the chicken embryo has provided insight on the mechanisms of teratogenesis of many compounds and also how this impact on drug safety.

Functional Polymorphisms in the p53 Pathway Genes on the Genetic Susceptibility to Zika Virus Teratogenesis

Congenital Zika Syndrome (CZS) occurs in up to 42% of individuals exposed to ZIKV prenatally. Deregulation in gene expression and protein levels of components of the p53 signaling pathway, such as p53 and MDM2, due to ZIKV infection has been reported. Here, we evaluate functional polymorphisms in genes of the p53 signaling pathway as risk factors to CZS. Forty children born with CZS and forty-eight children exposed to ZIKV, but born without congenital anomalies were included in this study. Gestational and sociodemographic information as well as the genotypic and allelic frequencies of functional polymorphisms in TP53, MDM2, MIR605 and LIF genes were compared between the two groups. We found children with CZS exposed predominantly in the first trimester and controls in the third trimester (p<0.001). Moreover, children with CZS were predominantly from families with a lower socioeconomic level (p=0.008). We did not find a statistically significant association between the investigated polymorphisms and development of CZS; however, by comparing individuals with CZS and lissencephaly or without lissencephaly, we found a significative difference in the allelic frequencies of the TP53 rs1042522, which is associated with a more potent p53-induced apoptosis (p=0.007). Our findings suggest that the TP53 rs1042522 polymorphism should be better investigate as a genetic risk factor for the development of lissencephaly in children with CZS.

Classification of Congenital Zika Syndrome: Muscle Tone, Motor Type, Body Segments Affected, and Gross Motor Function

Aim: To identify abnormalities in muscle tone and motor function associated with congenital Zika syndrome (CZS).Method: A cross-sectional observational study involving 96 children (55 males) with CZS at a mean (SD) age 35.2 ± 2.9 months. Children's muscle tone was investigated using the pull to sit, scarf sign, shoulder suspension and ventral suspension tests and the modified Ashworth scale (MAS). Motor impairment was determined using the Gross Motor Function Classification System (GMFCS) and body segments most affected with motor impairment.Results: 58 (60,5%) children tested positive for ≥1 maneuver used to evaluate muscle tone, while 38 (39.5%) tested negative in all the tests. MAS score was >0 for at least one of the appendicular muscles in 91 children (94.8%). In 88 children (91.7%), all four limbs were affected.Conclusion: Findings suggestive of axial hypotonia and appendicular hypertonia associated with severe motor impairment were prevalent in children with CZS.

Oral and maxillofacial outcomes in children with microcephaly associated with the congenital Zika syndrome

INTRODUCTION

The objective of this study is to assess the oral and maxillofacial characteristics of microcephalic children associated with congenital Zika syndrome (CZS).

METHODS

A cross-sectional, observational study was carried out with 61 patients with microcephaly/CZS born between June 2015 and September 2017 (29 boys and 32 girls, average age of 22.8 months) and a control group with 58 non-CZS children born in the same period (25 boys and 33 girls, average age of 23.8 months). The functional clinical analysis considered the labial and lingual frena, tongue anterior projection, oral escape, palate form, and first tooth eruption. For the craniofacial analysis, facial anthropometric points and the cephalic perimeter at the time were measured. Demographic data were collected from medical records, and a clinical exam was performed in order to register the intrabuccal characteristics and craniofacial measures. The chi-square test and Student's t-test were used with a significance level of 0.05.

RESULTS

The narrow palate form, tongue anterior projection, oral escape, and late first tooth eruption were significantly more present in the group with microcephaly/CZS. As for the craniofacial analysis, face width (Bi-Zi), mandible width (Go-Go), height of face upper third (Tr-G), and monthly growth of cephalic perimeter were significantly smaller, whereas height of face lower third (Sn-Gn) was significantly bigger in the group with microcephaly/CZS (P < 0.05).

CONCLUSION

Children with microcephaly resulting from a congenital Zika infection showed functional, oral, and maxillofacial changes and smaller facial development in comparison with non-CZS children in the same age group.

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.

Molecular mechanisms of Zika virus teratogenesis from animal studies: a systematic review protocol

BACKGROUND

Due to the diversity of studies in animal models reporting that molecular mechanisms are involved in the teratogenic effect of the Zika virus (ZIKV), the objective of the present study is to evaluate the methodological quality of these studies, as well as to demonstrate which genes and which molecular pathways are affected by ZIKV in different animal models.

METHODS

This search will be performed in four databases: PubMed/MEDLINE, EMBASE, Web of Science, and Scopus, as well as in the grey literature. The studies selection process will be reported through the PRISMA Statement diagram model. All studies describing the molecular mechanisms possibly involved in the development of malformations caused by embryonic/fetal ZIKV exposure in animal models with an appropriate control group and methodology will be included (including, for instance, randomized and non-randomized studies). All animals used as experimental models for ZIKV teratogenesis may be included as long as exposure to the virus occurred during the embryonic/fetal period. From the selected studies, data will be extracted using a previously prepared standard form. Bias risk evaluation will be conducted following the SYRCLE's Risk of Bias tool. All data obtained will be tabulated and organized by outcomes (morphological and molecular).

DISCUSSION

With the proposed systematic review, we expect to present results about the methodological quality of the published studies with animal models that investigated the molecular mechanisms involved in the teratogenic effect of ZIKV, as well as to show the studies with greater reliability.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019157316.

Early Gross Motor Development Among Brazilian Children with Microcephaly Born Right After Zika Virus Infection Outbreak

OBJECTIVE

To assess the gross motor development of children with presumed congenital Zika virus (ZIKV) infection over the first 2 years of their lives.

METHODS

Seventy-seven children were assessed at the median ages of 11, 18, and 24 months, using the evaluative instrument Gross Motor Function Measure (GMFM-66). At the third assessment, the children with diagnoses of cerebral palsy (CP) were classified by severity through the Gross Motor Function Classification System (GMFCS) and stratified by topography indicating the predominantly affected limbs. With these instruments in combination and using the motor development curves as reference, the rate of development and functional ability were estimated.

RESULTS

At 2 years of age, all children had the diagnosis of CP. Seventy-four (96.1%) presented gross motor skills similar to those of children aged 4 months or younger, according to the World Health Organization's standard. The GMFM-66 median score among the 73 (94.8%) children with quadriplegia and GMFCS level V showed significant change between 11 and 18 months (p < 0.001) and between 11 and 24 months (p < 0.001). No significant difference (p = 0.076) was found between 18 and 24 months.

CONCLUSION

Despite showing some gross motor progress during the initial 18 months of life, these children with presumed congenital ZIKV infection and CP experienced severe motor impairment by 2 years of age. According to the motor development curves, these children with quadriplegia have probably already reached about 90% of their motor development potential.

Case Report: Congenital Arthrogryposis and Unilateral Absences of Distal Arm in Congenital Zika Syndrome

Zika virus was recognized as a teratogen in 2015, when prenatal Zika infection was associated with neonatal microcephaly. The transmission, virulence, tropism, and consequences of Zika virus infection during pregnancy are currently studied. Decreased neural progenitor cells, arrest in neuronal migration and/or disruption of the maturation process of the fetus central nervous system have been associated. Congenital Zika Syndrome produces a fetal brain disruption sequence resulting in structural brain abnormalities, microcephaly, intracranial calcifications, fetal akinesia and arthrogryposis. Vascular abnormalities like unique umbilical artery and decreased cerebral vascular flow have been described in some patients. This article reports a Zika positive patient with sequence of fetal brain disruption, arthrogryposis and absence of distal third of the right forearm. This report expands the clinical observations of congenital Zika syndrome that may be related to disruptive vascular events.

Phenotypic spectrum and genomics of undiagnosed arthrogryposis multiplex congenita

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is characterised by congenital joint contractures in two or more body areas. AMC exhibits wide phenotypic and genetic heterogeneity. Our goals were to improve the genetic diagnosis rates of AMC, to evaluate the added value of whole exome sequencing (WES) compared with targeted exome sequencing (TES) and to identify new genes in 315 unrelated undiagnosed AMC families.

METHODS

Several genomic approaches were used including genetic mapping of disease loci in multiplex or consanguineous families, TES then WES. Sanger sequencing was performed to identify or validate variants.

RESULTS

We achieved disease gene identification in 52.7% of AMC index patients including nine recently identified genes (CNTNAP1, MAGEL2, ADGRG6, ADCY6, GLDN, LGI4, LMOD3, UNC50 and SCN1A). Moreover, we identified pathogenic variants in ASXL3 and STAC3 expanding the phenotypes associated with these genes. The most frequent cause of AMC was a primary involvement of skeletal muscle (40%) followed by brain (22%). The most frequent mode of inheritance is autosomal recessive (66.3% of patients). In sporadic patients born to non-consanguineous parents (n=60), de novo dominant autosomal or X linked variants were observed in 30 of them (50%).

CONCLUSION

New genes recently identified in AMC represent 21% of causing genes in our cohort. A high proportion of de novo variants were observed indicating that this mechanism plays a prominent part in this developmental disease. Our data showed the added value of WES when compared with TES due to the larger clinical spectrum of some disease genes than initially described and the identification of novel genes.

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.

Zika Virus-Associated Birth Defects, Costa Rica, 2016-2018

Enhanced birth defect surveillance increased identification of virus-associated abnormalities, including microcephaly.

After Zika virus (ZIKV) infection in Costa Rica was confirmed in January 2016, the national surveillance system was enhanced to monitor associated birth defects. To characterize the ZIKV outbreak among live-born infants during March 2016–March 2018, we conducted a descriptive analysis. Prevalence of ZIKV-associated birth defects was 15.3 cases/100,000 live births. Among 22 infants with ZIKV-associated birth defects, 11 were designated as confirmed (positive for ZIKV) and 11 were designated as probable cases (negative for ZIKV or not tested, but mother was expsed to ZIKV during pregnancy). A total of 91% had microcephaly (head circumference >2 SDs below mean for age and sex), 64% severe microcephaly (head circumference > 3 SDs below mean for age and sex), 95% neurodevelopmental abnormalities, 82% brain anomalies, 41% eye abnormalities, and 9% hearing loss. Monitoring children for > 1 year can increase identification of ZIKV-associated abnormalities in addition to microcephaly.

Gross Motor Function in Children with Congenital Zika Syndrome

BACKGROUND

Little information on gross motor function of congenital Zika syndrome (CZS) children is available.

OBJECTIVES

To evaluate gross motor function in CZS children aged up to 3 years, and its associated factors and changes in a minimum interval of 6 months.

METHODS

One hundred children with CZS and cerebral palsy (36 with confirmed and 64 with presumed CZS) were evaluated with the Gross Motor Function Classification System (GMFCS) and Gross Motor Function Measure (GMFM-88/GMFM-66). Forty-six were reevaluated. Wilcoxon tests, Wilcoxon tests for paired samples, percentile scores, and score changes were performed.

RESULTS

Clinical and socioeconomic characteristics (except maternal age), GMFM scores and GMFCS classification of confirmed and probable cases, which were analyzed together, were similar. The mean age was 25.6 months (±5.5); the median GMFM-88 score was 8.0 (5.4-10.8); and the median GMFM-66 score was 20.5 (14.8-23.1); 89% were classified as GMFCS level V. Low economic class, microcephaly at birth, epilepsy, and brain parenchymal volume loss were associated with low GMFM-66 scores. The median GMFM-66 percentile score was 40 (20-55). On the second assessment, the GMFM-66 scores in two GMFCS level I children and one GMFCS level IV child improved significantly. In one GMFCS level III child, one GMFCS level IV child, and the group of GMFCS level V children, no significant changes were observed.

CONCLUSIONS

Almost all CZS children had severe cerebral palsy; in the third year of life, most presented no improvement in gross motor function and were likely approaching their maximal gross motor function potential.

The Prevalence of Adenoid Hypertrophy among Children with Zika Related Microcephaly

Upper respiratory obstruction is a common sequela in children with Zika-related microcephaly (ZRM). As a cross-sectional analysis nested in a cohort study, this study aims to investigate the prevalence of adenoid hypertrophy (AH) in children with ZRM and symptoms of respiratory obstruction. The data were collected in the first three years of life from children with ZRM who were followed in two reference centers for otorhinolaryngological care of patients with congenital Zika syndrome. Out of 92 children with confirmed ZRM, 57 were evaluated by nasopharyngoscopy after presenting with upper respiratory obstruction symptoms. In this study, 31 of the 57 (54%) children with ZRM who were evaluated had obstructive AH. Thirteen children with obstructive AH were submitted to surgery, which resulted in the complete resolution of symptoms for 11, partial resolution in 1, and no improvement in 1. No evidence of direct involvement by Zika virus (ZIKV) infection in the adenoid tissues was demonstrated by histology or immunohistochemistry. Our results suggest that there is a high prevalence and early presentation of AH in children with ZRM, with consequent upper airway obstruction causing upper airway obstructive disorder, secretory otitis media, and dysphagia.

Prevalence of microcephaly: the Latin American Network of Congenital Malformations 2010-2017

OBJECTIVE

The Latin American Network of Congenital Malformations: ReLAMC was established in 2017 to provide accurate congenital anomaly surveillance. This study used data from ReLAMC registries to quantify the prevalence of microcephaly from 2010 to 2017 (before, during and after the Zika virus epidemic).

DESIGN

Nine ReLAMC congenital anomaly registries provided case-level data or aggregate data for any live births, still births or terminations of pregnancy with microcephaly. Births to pregnant women infected with Zika virus first occurred in Brazil in 2015, and in the remaining registry areas in 2016 with the exception of Chile that did not experience Zika virus. Therefore the prevalence of microcephaly for 2010-2014 and individual years 2015, 2016 and 2017 was estimated using multilevel random effect Poisson models. Clinical classification and characteristics of the cases were compared pre and post Zika for all centres providing individual case-level data.

RESULTS

The prevalence of microcephaly for all registries excluding Brazil was 2.3 per 10 000 (95% CI 2.0 to 2.6) for 2010-2014 rising to 5.4 (95% CI 4.8 to 6.0) in 2016 and 5.9 (95% CI 5.3 to 6.6) in 2017. Brazil had a prevalence of 0.6 per 10 000 (95% CI 0.5 to 0.6) in 2010-2014, rising to 5.8 (95% CI 5.6 to 6.1) in 2015, 8.0 (95% CI 7.6 to 8.3) in 2016 and then falling in 2017. Only 29 out of 687 cases of microcephaly were reported as congenital Zika syndrome in countries excluding Brazil.

CONCLUSIONS

The prevalence of microcephaly was influenced both by Zika causing congenital Zika syndrome and by increased reporting awareness.

Discordant Clinical Outcomes in a Monozygotic Dichorionic-Diamniotic Twin Pregnancy with Probable Zika Virus Exposure. Case Report

Prenatal exposure to Zika virus (ZIKV) is associated with congenital anomalies of the brain and the eye and neurodevelopmental sequelae. The spectrum of disease outcomes may relate to timing of infection as well as genetic and environmental factors. Congenital infections occurring in twin pregnancies can inform the clinical spectrum of these conditions and provide unique information regarding timing of infection and in utero environment with disease pathophysiology. Herein, we report a monozygotic dichorionic-diamniotic twin pregnancy with probable prenatal ZIKV exposure identified through the Colombian ZIKV disease surveillance system. Multidisciplinary clinical evaluations were provided to the twins during their first three years of life through a national program for children with in utero ZIKV exposure. Laboratory evidence of congenital infection as well as microcephaly, brain, eye, and neurodevelopmental compromise related to prenatal ZIKV infection were identified in only one infant of the twin pregnancy. This is the first report of monozygotic twins discordant for Zika-associated birth defects. The evaluation of the pathophysiology of discordance in disease outcome for congenital infections in twin pregnancies may lead to a better understanding of potential complex environmental and genetic interactions between the mother, her offspring, and an infectious exposure.

Congenital Zika syndrome: A systematic review

BACKGROUND

The signs and symptoms of Zika virus infection are usually mild and self-limited. However, the disease has been linked to neurological complications such as Guillain-Barré syndrome and peripheral nerve involvement, and also to abortion and fetal deaths due to vertical transmission, resulting in various congenital malformations in newborns, including microcephaly. This review aimed to describe the o signs and symptoms that characterize the congenital Zika syndrome.

METHODS AND FINDINGS

A systematic review was performed with a protocol and described according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search strategy yielded 2,048 studies. After the exclusion of duplicates and application of inclusion criteria, 46 studies were included. The main signs and symptoms associated with the congenital Zika syndrome were microcephaly, parenchymal or cerebellar calcifications, ventriculomegaly, central nervous system hypoplasia or atrophy, arthrogryposis, ocular findings in the posterior and anterior segments, abnormal visual function and low birthweight for gestational age.

CONCLUSIONS

Zika virus infection during pregnancy can cause a series of changes in the growth and development of children, while impacting the healthcare system due to the severity of cases. Our findings outline the disease profile in newborns and infants and may contribute to the development and updating of more specific clinical protocols.

The Latin American network for congenital malformation surveillance: ReLAMC

The early detection of congenital anomaly epidemics occurs when comparing current with previous frequencies in the same population. The success of epidemiologic surveillance depends on numerous factors, including the accuracy of the rates available in the base period, wide population coverage, and short periodicity of analysis. This study aims to describe the Latin American network of congenital malformation surveillance: ReLAMC, created to increase epidemiologic surveillance in Latin America. We describe the main steps, tasks, strategies used, and preliminary results. From 2017 to 2019, five national registries (Argentina [RENAC], Brazil [SINASC/SIM-BRS], Chile [RENACH], Costa Rica [CREC], Paraguay [RENADECOPY-PNPDC]), six regional registries (Bogotá [PVSDC-Bogota], Cali [PVSDC-Cali], Maule [RRMC SSM], Nicaragua [SVDC], Nuevo-León [ReDeCon HU], São Paulo [SINASC/SIM-MSP]) and the ECLAMC hospital network sent data to ReLAMC on a total population of 9,152,674 births, with a total of 101,749 malformed newborns (1.1%; 95% CI 1.10-1.12). Of the 9,000,651 births in countries covering both live and stillbirths, 88,881 were stillborn (0.99%; 95% CI 0.98-0.99), and among stillborns, 6,755 were malformed (7.61%; 95% CI 7.44-7.79). The microcephaly rate was 2.45 per 10,000 births (95% CI 2.35-2.55), hydrocephaly 3.03 (2.92-3.14), spina bifida 2.89 (2.78-3.00), congenital heart defects 15.53 (15.27-15.79), cleft lip 2.02 (1.93-2.11), cleft palate and lip 2.77 (2.66-2.88), talipes 2.56 (2.46-2.67), conjoined twins 0.16 (0.14-0.19), and Down syndrome 5.33 (5.18-5.48). Each congenital anomaly showed heterogeneity in prevalence rates among registries. The harmonization of data in relation to operational differences between registries is the next step in developing the common ReLAMC database.

Defining dysmorphic facial features in congenital Zika syndrome

Congenital Zika syndrome (CZS) constitutes a recently identified malformation caused by Zika virus infection during pregnancy. Limited data is available to date on the facial dysmorphic features of these patients. This study evaluated the facial dysmorphisms of children with CZS, compared with clinically healthy children, using clinical examination and standardized photographic images. Sixty-three children with CZS (9.70 ± 3.2 months-age), and 31 Controls (8.67 ± 6.2 months-age) joined the study. Seven out of 15 indices differed between groups: midfacial height (MFH)/horizontal facial reference (HFR) (p = .0003), interalar distance/HFR (p = .0027), nasal root depth/MFH (p = .0030), posterior nasal length/MFH (p = .0002), vertical position of the ear/MFH (p <.0001), ear length/MFH (p = .0005), chin height/total facial height (CH/TFH) (p <.0001). A CH/TFH of 0.229 showed 93.9% sensitivity and 80.6% specificity in diagnosing CZS. Children with CZS had broad, short faces, decreased intercanthal distance, short posterior nasal length, prominent nasal root, broad nasal wings, and high-set and long ears. Increased chin height index provided the most accurate diagnostic potential.

Neurological Findings in Children without Congenital Microcephaly Exposed to Zika Virus in Utero: A Case Series Study

The Zika virus can induce a disruptive sequence in the fetal brain and is manifested mainly by microcephaly. Knowledge gaps still exist as to whether the virus can cause minor disorders that are perceived later on during the first years of life in children who are exposed but are asymptomatic at birth. In this case series, we describe the outcomes related to neurodevelopment through the neurological assessment of 26 non-microcephalic children who had intrauterine exposure to Zika virus. Children were submitted for neurological examinations and Bayley Scales-III (cognition, language, and motor performance). The majority (65.4%) obtained satisfactory performance in neurodevelopment. The most impaired domain was language, with 30.7% impairment. Severe neurological disorders occurred in five children (19.2%) and these were spastic hemiparesis, epilepsy associated with congenital macrocephaly (Zika and human immunodeficiency virus), two cases of autism (one exposed to Zika and Toxoplasma gondii) and progressive sensorineural hearing loss (GJB2 mutation). We concluded that non-microcephalic children with intrauterine exposure to Zika virus, in their majority, had achieved satisfactory performance in all neurodevelopmental domains. One third of the cases had some impairment, but the predominant group had mild alterations, with low occurrence of moderate to severe disorders, similar to other studies in Brazil.

Orthopaedic approach to the congenital Zika syndrome

PURPOSE

The aim of this study is to present a case series of patients with congenital Zika syndrome (CZS), giving special attention to the more relevant aspects for the paediatric orthopaedic surgeon.

METHODS

An analytical cross-sectional study was performed in a group of 47 patients affected by CZS with maternal Zika serology confirmation. Clinical features of the maternal Zika infection, prenatal and perinatal complications, and patient demographic data were recorded. In addition, clinical and radiographic evaluations of the lower limb (hip, knee, and foot) were performed.

RESULTS

Maternal Zika infection occurred at an average of 12.5 (± 6.4) weeks of gestation. The rates of complications during pregnancy and delivery were 37% and 17.4%, respectively. At the time of the clinical evaluation, spasticity was appreciated in 77.3% of the cases, and arthrogryposis was present in 15.2%. Foot deformities were appreciated in 41.2% of the cases, hip alterations in aggregate in 29.8% (adduction contracture in 20.2%; displacement in 7.5%), and knee alterations in 12.8% (displacement in 6.4%). The deformities in arthrogrypotic patients were both more prevalent and severe. All arthrogrypotic patients were simultaneously spastic.

CONCLUSIONS

The current study demonstrates a high prevalence of musculoskeletal alterations in patients with CZS. Affected patients were able to be classified as belonging to one of three types at the time of evaluation: Type I patients presented with a low incidence of musculoskeletal complications; Type II demonstrated progressive deformities; Type III presented with simultaneously the most prevalent and severe deformities. This classification system could help guide medical and surgical management of CZS patients based on the frequency and severity of the deformities at the time of initial evaluation.

Movement disorders in children with congenital Zika virus syndrome

BACKGROUND

Congenital Zika Virus Syndrome (CZVS) denotes the neurologic and developmental sequelae of congenital infection of the Zika virus. While prior studies have detailed the associated clinical phenotypes, new findings continue to be identified. Abnormal postures and movements have been previously described in children with CZVS, but not in detail.

OBJECTIVE

To examine a cohort of infants with CZVS and characterize the spectrum of motor abnormalities, especially movement disorders.

DESIGN

Cross-sectional prospective study of 21 infants with confirmed CZVS.

SETTING

Single-center cohort of 32 patients with serologically confirmed CZVS cared for in a referral center in Brazil.

PARTICIPANTS

21 children (67% female), evaluated by two child neurologists and one movement disorders specialist, with clinical and laboratory diagnosis of CZVS aged between 16 and 30 months, with a mean age of 16 months at the time of the last examination.

MAIN OUTCOME(S) AND MEASURE(S)

Prospective neurologic examination by a team of three neurologists, including one movement disorders specialist. Sixteen (76.2%) children had a longitudinal evaluation with a six-month interval. The same team of experts analyzed recorded videos of all patients to characterize motor abnormalities and movement disorders. Neuroimaging findings were also analyzed to correlate with clinical findings.

RESULTS

Twenty (95.2%) patients presented with dystonic postures, including "125" posture of the fingers in 17 (80.1%), "swan neck" posture of the fingers in three (18.8%), oromandibular dystonia in nine (42.9%), extensor axial hypertonia in eight (38.1%) and internal rotation of the shoulder posture in two (9.5%). Four (19%) patients had tremor. All children had malformations of cortical development, and in 13 (61.9%), the pattern was consistent with a severe and diffuse gyral simplification. Seventeen children (81%) had calcification in the transition of grey and white matter, whereas 11 (52.4%) patients had basal ganglia calcifications.

CONCLUSION AND RELEVANCE

In our series, dystonic postures and other extrapyramidal signs were frequent and potentially disabling. Although children with CZVS are assessed and treated for spasticity, dystonia and other movement disorders remain neglected. This study emphasizes that extrapyramidal findings may potentially influence optimal strategies for rehabilitation and management.

Speech-language disorders in children with congenital Zika virus syndrome: A systematic review

INTRODUCTION

Having verified the true association between the Zika virus and the occurrence of microcephaly, studies were conducted to evaluate the effects of the infection on fetal development. Congenital Zika virus syndrome is a currently known condition but little addressed regarding speech, language, and hearing disorders in children.

OBJECTIVE

To conduct a systematic review of speech, language, and hearing disorders in children with congenital Zika virus syndrome.

METHODS

This systematic review followed the PRISMA instructions and the Joanna Briggs Institute guidelines, and it was registered in PROSPERO (CRD42018111764). The databases consulted were Cochrane, SciELO, PubMed, LILACS, Scopus, Web of Science, and ScienceDirect. OpenGrey and OpenThesis were used to partially capture the "grey literature". Observational studies of children with microcephaly due to congenital Zika virus syndrome were included. The risk of bias was analyzed using the 2017 Joanna Briggs Institute.

RESULTS

707 records were obtained and, after excluding the duplicates, 644 studies remained. After applying the inclusion criteria, 24 articles were considered eligible. Children with congenital Zika virus syndrome presented abnormal persistence of primitive reflexes (94.7%), impaired cognitive development (95.1%), delayed neuropsychomotor development (between 92.8 and 100%), hypertonia (between 74.7% and 90.1%), impaired language development (between 68.42% and 100%), retrognathia (38.6%), craniofacial disproportion (between 32.9% and 95.8%), altered tongue frenulum (between 30% and 36.36%), the absence of stapedial reflexes (27.3%), dysphagia (between 14% and 88.9%), and hearing changes (between 5.8% and 68.42%).

CONCLUSION

Children with congenital Zika virus syndrome may have speech, language, and hearing disorders such as hearing loss, dysphagia, alteration in the tongue frenulum, and delays in neuropsychomotor and language development.

Plaque Reduction Neutralization Test (PRNT) in the Congenital Zika Syndrome: Positivity and Associations with Laboratory, Clinical, and Imaging Characteristics

The short duration of viremia, low blood viral load, inaccessibility to timely specific diagnostic tests, and cross-reactions with other flaviviruses have hindered laboratory confirmation of Congenital Zika Syndrome (CZS). This study analyzes the positivity of the plaque reduction neutralization test (PRNT) in children with clinical or imaging characteristics of CZS and its association with laboratory, clinical, and imaging characteristics. The 94 clinical cases of CZS submitted to the ZIKV PRNT₉₀ test were followed from 2016 to 2018. The mean age of children at PRNT₉₀ collection was 22 ± 6 months Standard Deviation. The ZIKV PRNT₉₀ was positive (titer ≥ 10) in 40 (42.5%) children. ZIKV PRNT₉₀ positivity was associated with severe microcephaly in newborns (p = 0.016), lower head circumference z-score at birth (p = 0.043) and 24 months of age (p = 0.031), and severe reduction of the cerebral parenchyma volume (p = 0.021), expressing greater disease severity. Negative PRNT₉₀ in children with characteristic signs of CZS may be due to false-negative results, indicating that the diagnosis of CZS should be primarily syndromic.

Barreto F, Itaparica Carvalho MS, Oliveira WK, França GVA, Carmo EH, Andrade RFS, Rodrigues MS, Veiga RV, Oliveira JF, Fernandes QHRF, Costa LC, Coelho GE, Paixao ES. Case Fatality Rate Related to Microcephaly Congenital Zika Syndrome and Associated Factors: A Nationwide Retrospective Study in Brazil †

BACKGROUND

The clinical manifestations of microcephaly/congenital Zika syndrome (microcephaly/CZS) have harmful consequences on the child's health, increasing vulnerability to childhood morbidity and mortality. This study analyzes the case fatality rate and child-maternal characteristics of cases and deaths related to microcephaly/CZS in Brazil, 2015-2017.

METHODS

Population-based study developed by linkage of three information systems. We estimate frequencies of cases, deaths, case fatality rate related to microcephaly/CZS according to child and maternal characteristics and causes of death. Multivariate logistic regression models were applied.

RESULTS

The microcephaly/CZS case fatality rate was 10% (95% CI 9.2-10.7). Death related to microcephaly/CZS was associated to moderate (OR = 2.15; 95% CI 1.63-2.83), and very low birth weight (OR = 3.77; 95% CI 2.20-6.46); late preterm births (OR = 1.65; 95% CI 1.21-2.23), Apgar < 7 at 1st (OR = 5.98; 95% CI 4.46-8.02) and 5th minutes (OR = 4.13; 95% CI 2.78-6.13), among others.

CONCLUSIONS

A high microcephaly/CZS case fatality rate and important factors associated with deaths related to this syndrome were observed. These results can alert health teams to these problems and increase awareness about the factors that may be associated with worse outcomes.

Cross-sectional study of the anthropometric characteristics of children with congenital Zika syndrome up to 12 months of life

Background

Little is known about physical development of children with Congenital Zika Syndrome (CZS). This study aims to evaluate the anthropometric characteristics of children with CZS up to 12 months.

Methods

This is a cross-sectional study developed with 46 children with CZS living in Bahia. We used the Public Health Events Register, Live Births Information System and Childcare Records of Primary Health Care Services. Descriptive analysis was performed by distributing absolute and relative frequencies and median and interquartile range. The Weight/Age (W/A), Length/Age (L/A), Weight/Length (W/L) and Head Circumference/Age (HC/A) indexes were calculated for each month and expressed in z-score values, and the results were evaluated individually and by group average. Values between ≥ − 2 and ≤ 2 standard deviations were used as reference. T-Student and Spearman’s Correlation Tests were applied to verify the existence of any relationship between maternal and children’s variables with the anthropometric indexes weight/age and height/age at birth and at 3, 6 and 12 months of age.

Results

The studied children had high proportions of low birth weight (23.9%), dysphagia (56.8%) and seizures (53.5%). The mean z-score for the HC/A index at birth was − 3.20 and remained below − 3 z-scores throughout the assessed period. The analysis of the indices equivalent to every single child’s anthropometric measurement showed a deficit in 20.4% of the W/A, 39.1% of the L/A, 9.2% of the W/L and 85.7% of the HC/A measurements. Distribution of the mean values of these anthropometric indices revealed a risk of delayed stature growth (L/A < -1 z-score). There was a statistically significant association between L/A at 12 months and dysphagia (p = 0.0148) and a positive correlation between breastfeeding time and W/A. No statistically significant correlation was found between any other tested variables.

Conclusions

We observed a deficit in the HC/A index, which is a common feature in CZS, but also a high proportion of W/A and L/A deficit. The average group z-score highlighted the risk of delay in stature growth for age, which calls attention to the need for health interventions, as this condition exposes them to a higher risk of morbidity and mortality.

Zika virus-induced brain malformations in chicken embryos

BACKGROUND

Zika virus (ZIKV) was confirmed to be related to microcephaly in 2016. However, there is still a need for understanding the embryonic morphological changes induced by ZIKV and when they occur. Here, chicken embryos were chosen as experimental model of ZIKV to evaluate virus-associated morphological alterations that might take place during embryonic development.

METHODS

A screening with different viral doses was conducted in embryos at HH Stage 10-12 (E1.5) as well as a follow up of the first 5 days postinfection (dpi) was performed to observe the main morphologic changes post ZIKV infection.

RESULTS

ZIKV exposed embryos presented a higher prevalence of mortality and defects such as brain malformation when compared to controls. Moreover, we observed that the phenotypes become more evident at 4dpi, when the viral load quantification reaches a peak.

CONCLUSIONS

We found that ZIKV exposed embryos presented a high prevalence of mortality and central nervous system (CNS) abnormalities in a dose-dependent manner. The phenotype was more evident 4 days postinfection, when the viral load quantification reached a peak.

Early Growth Parameters as Predictors of Developmental Delay Among Children Conceived During the 2015-2016 Zika Virus Outbreak in Northeastern Brazil

Background: Identifying infants with congenital infection for early intervention will likely be challenging in future Zika virus outbreaks. We investigated indicators of risk for developmental delay among children born with and without obvious manifestations of congenital Zika virus infection. Methods: We evaluated 120 children conceived during the 2015−2016 Zika virus outbreak in Paraíba, Brazil. We analyzed data from children at birth; ages 1−7 months and approximately 24 months, using medical records (i.e., anthropometric measurements diagnoses), medical evaluation (i.e., Zika/other laboratory tests, dysmorphic features), and parent report (seizures, developmental delay). We used a Bayesian modeling approach to identify predictors of developmental delay. Results: Head circumference (HC) and length at birth and rates of growth for HC and length at follow-up were consistent across domains of developmental delay; (e.g., for every 1 cm per month decrease in HC growth rate; there was a corresponding decrease in the gross motor z-score). Modeling results indicated that HC and length at birth, and follow-up HC and length rates of growth, were predictive of developmental delay. Conclusion: These findings suggest that accurate measurement and frequent monitoring of HC and length, especially in the first few months of life, may be useful for identifying children possibly congenitally exposed to Zika virus who could benefit from early intervention services.

Potent Restriction of Sexual Zika Virus Infection by the Lipid Fraction of Extracellular Vesicles in Semen

Sexual Zika virus (ZIKV) transmission from men to women occurs less frequently than the often-detected high viral loads in semen would suggest, but worries that this transmission route predisposes to fetal damage in pregnant women remain. To better understand sexual ZIKV pathogenesis, we studied the permissiveness of the human female genital tract to infection and the effect of semen on this process. ZIKV replicates in vaginal tissues and primary epithelial cells from the vagina, ectocervix, and endocervix and induces an innate immune response, but also continues to replicate without cytopathic effect. Infection of genital cells and tissues is strongly inhibited by extracellular vesicles (EV) in semen at physiological vesicle-to-virus ratios. Liposomes with the same composition as semen EVs also impair infection, indicating that the EV’s lipid fraction, rather than their protein or RNA cargo, is responsible for this anti-viral effect. Thus, EVs in semen potently restrict ZIKV transmission, but the virus propagates well once infection in the recipient mucosa has been established.

Congenital Zika Virus Infection: a Review with Emphasis on the Spectrum of Brain Abnormalities

Purpose of Review

In 2016, the World Health Organization declared the Zika virus (ZIKV) outbreak a Public Health Emergency of International Concern following a cluster of associated neurological disorders and neonatal malformations. Our aim is to review the clinical and neuroimaging findings seen in congenital Zika syndrome.

Recent Findings

ZIKV injures neural progenitor cells in the hippocampus, a brain region important for learning, memory, cognition, and emotion/stress response. Positron emission tomography has revealed global neuroinflammation in ZIKV infection in animal models.

Summary

Congenital Zika syndrome is associated with a spectrum of brain abnormalities, including microcephaly, parenchymal calcifications, malformations of cortical development and defective neuronal migration, corpus callosum abnormalities, ventriculomegaly, and brainstem and cerebellar abnormalities.

Continuous epileptiform discharges during sleep as an evolutionary pattern in patients with congenital Zika virus syndrome

Congenital Zika virus syndrome (CZVS) is associated with severe neurological deficits. Clinical characteristics of epilepsy and the electroencephalographic (EEG) pattern in CZVS were documented in infancy. In this study, we aimed to describe the EEG findings observed during the follow-up of children with CZVS. Seventy-six EEGs of 55 children (60% female; mean age = 50 months) with confirmed CZVS were analyzed, considering the background, interictal, and ictal epileptiform discharges. Continuous (or almost continuous) epileptiform discharges during non-rapid eye movement sleep were identified in 22 (40%) patients. In 20 (90.1%) patients, the pattern was symmetrical, with an anterior predominance of the epileptiform activity. All patients with this pattern had epilepsy, which was severe in 15 (68.2%) and demanded polytherapy in 19 (86.4%). Subcortical calcifications (77.3%) and multifocal EEGs (72.8%) in earlier ages occurred more often in patients with this pattern. Other unspecific interictal EEG patterns were focal epileptiform discharges in 23 (41.8%) and multifocal activity in six (10.9%). In CZVS, continuous (or almost continuous) epileptiform discharges during sleep emerge as a pattern after the second year of life. This was associated with severe and drug-resistant epilepsy, but not necessarily with an apparent regression. Subcortical calcifications and multifocal epileptiform discharges in infancy are associated with this pattern.

Differential gene expression elicited by ZIKV infection in trophoblasts from congenital Zika syndrome discordant twins

Zika virus (ZIKV) causes congenital Zika syndrome (CZS), which is characterized by fetal demise, microcephaly and other abnormalities. ZIKV in the pregnant woman circulation must cross the placental barrier that includes fetal endothelial cells and trophoblasts, in order to reach the fetus. CZS occurs in ~1-40% of cases of pregnant women infected by ZIKV, suggesting that mothers' infection by ZIKV during pregnancy is not deterministic for CZS phenotype in the fetus. Therefore, other susceptibility factors might be involved, including the host genetic background. We have previously shown that in three pairs of dizygotic twins discordant for CZS, neural progenitor cells (NPCs) from the CZS-affected twins presented differential in vitro ZIKV susceptibility compared with NPCs from the non-affected. Here, we analyzed human-induced-pluripotent-stem-cell-derived (hiPSC-derived) trophoblasts from these twins and compared by RNA-Seq the trophoblasts from CZS-affected and non-affected twins. Following in vitro exposure to a Brazilian ZIKV strain (ZIKVBR), trophoblasts from CZS-affected twins were significantly more susceptible to ZIKVBR infection when compared with trophoblasts from the non-affected. Transcriptome profiling revealed no differences in gene expression levels of ZIKV candidate attachment factors, IFN receptors and IFN in the trophoblasts, either before or after ZIKVBR infection. Most importantly, ZIKVBR infection caused, only in the trophoblasts from CZS-affected twins, the downregulation of genes related to extracellular matrix organization and to leukocyte activation, which are important for trophoblast adhesion and immune response activation. In addition, only trophoblasts from non-affected twins secreted significantly increased amounts of chemokines RANTES/CCL5 and IP10 after infection with ZIKVBR. Overall, our results showed that trophoblasts from non-affected twins have the ability to more efficiently activate genes that are known to play important roles in cell adhesion and in triggering the immune response to ZIKV infection in the placenta, and this may contribute to predict protection from ZIKV dissemination into fetuses' tissues.

Zika Virus Changes Methylation of Genes Involved in Immune Response and Neural Development in Brazilian Babies Born With Congenital Microcephaly

The recent increase in babies born with brain and eye malformations in Brazil is associated with Zika virus (ZIKV) infection in utero. ZIKV alters host DNA methylation in vitro. Using genome-wide DNA methylation profiling we compared 18 babies born with congenital ZIKV microcephaly with 20 controls. We found ZIKV-associated alteration of host methylation patterns, notably at RABGAP1L which is important in brain development, at viral host immunity genes MX1 and ISG15, and in an epigenetic module containing the causal microcephaly gene MCPH1. Our data support the hypothesis that clinical signs of congenital ZIKV are associated with changes in DNA methylation.

Etiology of Microcephaly and Central Nervous System Defects during the Zika Epidemic in Colombia

OBJECTIVE

To estimate the prevalence of microcephaly and central nervous system (CNS) defects during the Zika virus (ZIKV) epidemic in Colombia and proportion attributable to congenital ZIKV infection.

STUDY DESIGN

Clinical and laboratory data for cases of microcephaly and/or CNS defects reported to national surveillance between 2015 and 2017 were reviewed and classified by a panel of clinical subject matter experts. Maternal and fetal/infant biologic specimens were tested for congenital infection and chromosomal abnormalities. Infants/fetuses with microcephaly and/or CNS defects (cases) were classified into broad etiologic categories (teratogenic, genetic, multifactorial, and unknown). Cases classified as potentially attributable to congenital ZIKV infection were stratified by strength of evidence for ZIKV etiology (strong, moderate, or limited) using a novel strategy considering birth defects unique or specific to ZIKV or other infections and laboratory evidence.

RESULTS

Among 858 reported cases with sufficient information supporting a diagnosis of microcephaly or CNS defects, 503 were classified as potentially attributable to congenital ZIKV infection. Of these, the strength of evidence was considered strong in 124 (24.7%) cases; moderate in 232 (46.1%) cases; and limited in 147 (29.2%). Of the remaining, 355 (41.4%) were attributed to etiologies other than ZIKV infection (syphilis, toxoplasmosis, rubella, cytomegalovirus, herpes 1 and herpes 2 viruses only, n = 32 [3.7%]; genetic, n = 16 [1.9%]; multifactorial, n = 42 [4.9%]; unknown, n = 265 [30.9%]).

CONCLUSIONS

Fifty-eight percent of cases of microcephaly and/or CNS defects were potentially attributable to congenital ZIKV infection; however, the strength of evidence varied considerably. This surveillance protocol might serve as a model approach for investigation and etiologic classification of complex congenital conditions.

Motor development in non-microcephalic infants born to mothers with Zika Virus infection during pregnancy

ABSTRACT This cross-sectional study sought to evaluate motor development in infants exposed to ZIKV born with normal head circumference (HC). Thirty one children, distributed into two groups, participated in the study: 15 whose mothers were infected by ZIKV during pregnancy, born with HC from −1.9 to +2 Z-scores, adjusted for sex and gestational age (exposed group); and 16 randomly selected infants without known prenatal exposure to ZIKV, paired by sex and age (control group). Alberta Infant Motor Scale (AIMS) was used to evaluate gross motor development. We found no significant difference between the exposed and control groups. However, considering that AIMS is a screening test that assesses only the gross motor development and the small size of our sample, infants exposed to ZIKV during pregnancy should be continuously evaluated for different aspects of their development.

Long-term alterations in brain and behavior after postnatal Zika virus infection in infant macaques

Zika virus (ZIKV) infection has a profound impact on the fetal nervous system. The postnatal period is also a time of rapid brain growth, and it is important to understand the potential neurobehavioral consequences of ZIKV infection during infancy. Here we show that postnatal ZIKV infection in a rhesus macaque model resulted in long-term behavioral, motor, and cognitive changes, including increased emotional reactivity, decreased social contact, loss of balance, and deficits in visual recognition memory at one year of age. Structural and functional MRI showed that ZIKV-infected infant rhesus macaques had persistent enlargement of lateral ventricles, smaller volumes and altered functional connectivity between brain areas important for socioemotional behavior, cognitive, and motor function (e.g. amygdala, hippocampus, cerebellum). Neuropathological changes corresponded with neuroimaging results and were consistent with the behavioral and memory deficits. Overall, this study demonstrates that postnatal ZIKV infection in this model may have long-lasting neurodevelopmental consequences.

Clinical Outcomes of a Zika Virus Mother-Child Pair Cohort in Spain

Background: Zika virus (ZIKV) infection has been associated with congenital microcephaly and other neurodevelopmental abnormalities. There is little published research on the effect of maternal ZIKV infection in a non-endemic European region. We aimed to describe the outcomes of pregnant travelers diagnosed as ZIKV-infected in Spain, and their exposed children. Methods: This prospective observational cohort study of nine referral hospitals enrolled pregnant women (PW) who travelled to endemic areas during their pregnancy or the two previous months, or those whose sexual partners visited endemic areas in the previous 6 months. Infants of ZIKV-infected mothers were followed for about two years. Results: ZIKV infection was diagnosed in 163 PW; 112 (70%) were asymptomatic and 24 (14.7%) were confirmed cases. Among 143 infants, 14 (9.8%) had adverse outcomes during follow-up; three had a congenital Zika syndrome (CZS), and 11 other potential Zika-related outcomes. The overall incidence of CZS was 2.1% (95%CI: 0.4–6.0%), but among infants born to ZIKV-confirmed mothers, this increased to 15.8% (95%CI: 3.4–39.6%). Conclusions: A nearly 10% overall risk of neurologic and hearing adverse outcomes was found in ZIKV-exposed children born to a ZIKV-infected traveler PW. Longer-term follow-up of these children is needed to assess whether there are any later-onset manifestations.

Absence of Evidence of Zika Virus Infection in Cord Blood and Urine from Newborns with Congenital Abnormalities, Indonesia

Zika virus (ZIKV) has recently been confirmed as endemic in Indonesia, but no congenital anomalies (CA) related to ZIKV infection have been reported. We performed molecular and serological testing for ZIKV and other flaviviruses on cord serum and urine samples collected in October 2016 to April 2017 during a prospective, cross-sectional study of neonates in Jakarta, Indonesia. Of a total of 429 neonates, 53 had CA, including 14 with microcephaly. These 53, and 113 neonate controls without evidence of CA, were tested by ZIKV-specific real-time reverse transcription polymerase chain reaction (RT-PCR), pan-flavivirus RT-PCR, anti-ZIKV and anti-DENV IgM ELISA, and plaque reduction neutralization test. There was no evidence of ZIKV infection among neonates in either the CA or non-CA cohorts, except in three cases with low titers of anti-ZIKV neutralizing antibodies. Further routine evaluation throughout Indonesia of pregnant women and their newborns for exposure to ZIKV should be a high priority for determining risk.

A combination of two human monoclonal antibodies limits fetal damage by Zika virus in macaques

Zika virus (ZIKV) infection during pregnancy can cause fetal abnormalities. Vaccines against ZIKV are under development, but because of potential safety concerns due to disease-enhancing antibodies, and the time required by active immunization to induce protective antibodies, there is a need to explore alternative strategies. Recombinant monoclonal antibodies can be modified to prevent enhancement of infection, and thus could be an efficacious and safe alternative to vaccines to confer rapid protection. We show that prophylactic administration of two engineered antibodies, Z004 and Z021, to pregnant macaques partially protects against fetal neurologic damage and limits vertical transmission of ZIKV.

Human infection by Zika virus (ZIKV) during pregnancy can lead to vertical transmission and fetal aberrations, including microcephaly. Prophylactic administration of antibodies can diminish or prevent ZIKV infection in animal models, but whether passive immunization can protect nonhuman primates and their fetuses during pregnancy has not been determined. Z004 and Z021 are neutralizing monoclonal antibodies to domain III of the envelope (EDIII) of ZIKV. Together the two antibodies protect nonpregnant macaques against infection even after Fc modifications to prevent antibody-dependent enhancement (ADE) in vitro and extend their half-lives. Here we report on prophylactic coadministration of the Fc-modified antibodies to pregnant rhesus macaques challenged three times with ZIKV during first and second trimester. The two antibodies did not entirely eliminate maternal viremia but limited vertical transmission, protecting the fetus from neurologic damage. Thus, maternal passive immunization with two antibodies to EDIII can shield primate fetuses from the harmful effects of ZIKV.

Neurological outcomes of congenital Zika syndrome in toddlers and preschoolers: a case series

BACKGROUND

Congenital Zika syndrome causes a spectrum of neurological symptoms with varying effects on function that require different therapeutic strategies. To date, this spectrum of effects and its clinical implications have not been completely described. We describe the neurological examination findings in toddlers and preschoolers, including predominant symptom complexes and comorbidities.

METHODS

This study is a case-series neurological evaluation of 75 children with congenital Zika syndrome in Campina Grande, Brazil. The study is part of a cohort of children with congenital Zika syndrome that started in 2015 and is still ongoing. Children with Zika virus infection detected during pregnancy (mothers exhibited rash and were followed and diagnosed by fetal ultrasound abnormalities or RT-PCR) or through microcephaly screening after birth, using Intergrowth 21 guidelines, were selected by laboratory and radiological criteria. Children were examined during a 10-day period in September, 2018, and underwent neurological interview, examination, and assessment of functional outcomes and comorbidities. Children were divided in groups of predominant corticospinal or neuromuscular clinical signs and the associations between these groups and clinical comorbidities were assessed.

FINDINGS

All of the children recruited to the study from Nov 29, 2015 to Nov 30, 2017 had imaging correlates of congenital Zika syndrome. Children were assigned to groups depending on the signs exhibited, either corticospinal or neuromuscular, with or without dyskinetic signs. 75 children completed the evaluation, 38 (51%) girls and 37 (49%) boys. Median age was 33 months (range 26-40 months; IQR 29-34). Microcephaly was present at birth in 56 (75%) children, and 19 (25%) children were born with normal head circumference, 15 of whom later developed microcephaly. Neurological examination grouped four children as having isolated dyskinetic signs, 48 children were assigned to the corticospinal group and 23 into the neuromuscular group. Dyskinetic findings were present in 30 (40%) children, either alone (four [5%]) or combined with corticospinal (19 [40%] of 48) or neuromuscular (seven [30%] of 23) findings. Comorbidities were highly prevalent, and the neuromuscular group had worse functional outcomes, evaluated by gross motor function (p=0·026), manual abilities (p=0·0013), and communication function (p<0·0005) classification scales, than the corticospinal group, whereas pneumonia (p<0·0005) and urinary tract infections (p<0·0005) were more frequent in the corticospinal group. Cortical hyperexcitability was supported by several clinical correlates, such as early onset epilepsy, persistence of primitive reflexes, and dystonia.

INTERPRETATION

We describe distinct neurological profiles in the congenital Zika syndrome spectrum, with functional outcomes tending to correlate with these groups. The clinical division of children based on the disease signs proposed here is supported by the literature on central and peripheral nervous system pathology in congenital Zika syndrome. The high prevalence of dyskinetic symptoms merits special attention.

FUNDING

Brazilian National Council for Scientific and Technological Development and by the Coordination for the Improvement of Higher Education Personnel.

Experimental Infection of Mid-Gestation Pregnant Female and Intact Male Sheep with Zika Virus

Zika virus (ZIKV) is an arbovirus that causes birth defects, persistent male infection, and sexual transmission in humans. The purpose of this study was to continue the development of an ovine ZIKV infection model; thus, two experiments were undertaken. In the first experiment, we built on previous pregnant sheep experiments by developing a mid-gestation model of ZIKV infection. Four pregnant sheep were challenged with ZIKV at 57–64 days gestation; two animals served as controls. After 13–15 days (corresponding with 70–79 days of gestation), one control and two infected animals were euthanized; the remaining animals were euthanized at 20–22 days post-infection (corresponding with 77–86 days of gestation). In the second experiment, six sexually mature, intact, male sheep were challenged with ZIKV and two animals served as controls. Infected animals were serially euthanized on days 2–6 and day 9 post-infection with the goal of isolating ZIKV from the male reproductive tract. In the mid-gestation study, virus was detected in maternal placenta and spleen, and in fetal organs, including the brains, spleens/liver, and umbilicus of infected fetuses. Fetuses from infected animals had visibly misshapen heads and morphometrics revealed significantly smaller head sizes in infected fetuses when compared to controls. Placental pathology was evident in infected dams. In the male experiment, ZIKV was detected in the spleen, liver, testes/epididymides, and accessory sex glands of infected animals. Results from both experiments indicate that mid-gestation ewes can be infected with ZIKV with subsequent disruption of fetal development and that intact male sheep are susceptible to ZIKV infection and viral dissemination and replication occurs in highly vascular tissues (including those of the male reproductive tract).

Neurodevelopment of Nonmicrocephalic Children, After 18 Months of Life, Exposed Prenatally to Zika Virus

The aim of this work was to evaluate the cognitive, language, and motor development, after 18 months of life, of nonmicrocephalic children born to mothers with Zika virus infection during pregnancy. Participants were 37 children aged 18-29 months divided into 2 groups: 17 nonmicrocephalic children born to mothers who had Zika virus infection during pregnancy (ZIKVG) and 20 nonmicrocephalic children with no maternal history of infection matched by sex and age (control group). A semistructured interview and the Bayley Scale of Infant and Toddler Development (Bayley III) were used for their evaluation. One child in the ZIKVG presented low cognitive score, the same in the control group. There were no statistical differences between the 2 groups regarding cognitive, language, and motor development. This sample, although small, showed that a significant proportion of nonmicrocephalic children exposed prenatally to Zika virus had normal development. A longer follow-up is necessary to observe if no other adverse outcomes will appear in the future.

Chronology and sequence of deciduous teeth eruption in children with microcephaly associated to the Zika virus

INTRODUCTION

Deciduous teeth eruption is connected to children's growth and development. In Brazil, with the increase in the occurrence of children born with microcephaly associated to exposure to Zika virus, studies about orofacial alterations were necessary.

OBJECTIVE

Describe the chronology and sequence of deciduous teeth in children with microcephaly due to the fetal exposure to Zika virus.

METHODOLOGY

A cross-sectional study involving 74 children of a neuropediatric reference unit in Salvador, Bahia, in 2017 was conducted. Through use of secondary data, interviews with mothers and children's exam, the population was characterized, the chronology and sequence of deciduous teeth eruption was registered, and the analysis of the variables was proceeded.

RESULTS

The first eruption happened between 4 and 17 months of age and 52.70% had a delay in the eruption of incisors. The average eruption time for the maxilla varies from 17.92 (16.56-19.28; 95% CI) to 20.43 (19.35-21.51; 95% CI) months, and the jaw from 11.57 (6.85-18.99; 95% CI) to 20.20 (19.09-21.31; 95% CI) months. In 77.94% of population, the eruption of the first teeth was in the lower arch and in 33.82%, molars and/or canines erupted before the incisors.

CONCLUSIONS

There were alteration in the chronology and sequence of deciduous teeth eruption.

Inflammation markers in the saliva of infants born from Zika-infected mothers: exploring potential mechanisms of microcephaly during fetal development

Zika virus (ZIKV) has emerged as one of the most medically relevant viral infections of the past decades; the devastating effects of this virus over the developing brain are a major matter of concern during pregnancy. Although the connection with congenital malformations are well documented, the mechanisms by which ZIKV reach the central nervous system (CNS) and the causes of impaired cortical growth in affected fetuses need to be better addressed. We performed a non-invasive, metabolomics-based screening of saliva from infants with congenital Zika syndrome (CZS), born from mothers that were infected with ZIKV during pregnancy. We were able to identify three biomarkers that suggest that this population suffered from an important inflammatory process; with the detection of mediators associated with glial activation, we propose that microcephaly is a product of immune response to the virus, as well as excitotoxicity mechanisms, which remain ongoing even after birth.

Prevalence and causes of congenital microcephaly in the absence of a Zika virus outbreak in southern Brazil

OBJECTIVE

The aim of this study was to identify the causes of congenital microcephaly in Rio Grande do Sul, a state in southern Brazil, where no ZIKV outbreak was detected, from December 2015 to December 2016, which was the period when ZIKV infection was at its peak in northeast Brazil.

METHODS

This was a cross-sectional study where all notifications of congenital microcephaly in the state of Rio Grande do Sul were included for analysis. Evaluation of cases followed the guidelines of the Brazilian Ministry of Health. Dysmorphological and neurological evaluations were performed by a specialized team, and genetic tests and neuroimaging were performed when clinically indicated. STORCH infections were diagnosed using standard tests. ZIKV infection was diagnosed through maternal serum RT-PCR and/or neuroimaging associated with clinical/epidemiological criteria.

RESULTS

From 153744 registered live births in the study period, 148 cases were notified, but 90 (60.8%) of those were later excluded as "non-confirmed" microcephaly. In the 58 confirmed cases of microcephaly (prevalence = 3.8/10000 live births), congenital infections (syphilis, toxoplasmosis, cytomegalovirus, and ZIKV) constituted the predominant etiology (50.0%), followed by isolated CNS (15.5%), and genetic syndromes (10.3%). Congenital ZIKV syndrome (CZS) with typical phenotype was diagnosed in three cases (5.2% of all confirmed microcephaly cases or 10.4% of all congenital infections).

CONCLUSION

In Rio Grande do Sul, where no outbreak of ZIKV infection was recorded, congenital infections were the leading cause of congenital microcephaly, and the attributable risk for CZS in the etiology of microcephaly was 5.2%.