Congenital Zika syndrome: A systematic review

Multi-omics analysis of antiviral interactions of Elizabethkingia anophelis and Zika virus

The microbial communities residing in the mosquito midgut play a key role in determining the outcome of mosquito pathogen infection. Elizabethkingia anophelis, originally isolated from the midgut of Anopheles gambiae possess a broad-spectrum antiviral phenotype, yet a gap in knowledge regarding the mechanistic basis of its interaction with viruses exists. The current study aims to identify pathways and genetic factors linked to E. anophelis antiviral activity. The understanding of E. anophelis antiviral mechanism could lead to novel transmission barrier tools to prevent arboviral outbreaks. We utilized a non-targeted multi-omics approach, analyzing extracellular lipids, proteins, metabolites of culture supernatants coinfected with ZIKV and E. anophelis. We observed a significant decrease in arginine and phenylalanine levels, metabolites that are essential for viral replication and progression of viral infection. This study provides insights into the molecular basis of E. anophelis antiviral phenotype. The findings lay a foundation for in-depth mechanistic studies.

Clinical spectrum of congenital Zika virus infection in Brazil: Update and issues for research development

This review aimed to provide an update on the morphological and/or functional abnormalities related to congenital Zika virus (ZIKV) infection, based on primary data from studies conducted in Brazil since 2015. During the epidemic years (2015-2016), case series and pediatric cohort studies described several birth defects, including severe and/or disproportionate microcephaly, cranial bone overlap, skull collapse, congenital contractures (arthrogryposis and/or clubfoot), and visual and hearing abnormalities, as part of the spectrum of Congenital Zika Syndrome (CZS). Brain imaging abnormalities, mainly cortical atrophy, ventriculomegaly, and calcifications, serve as structural markers of CZS severity. Most case series and cohorts of microcephaly have reported the co-occurrence of epilepsy, dysphagia, orthopedic deformities, motor function impairment, cerebral palsy, and urological impairment. A previous large meta-analysis conducted in Brazil revealed that a confirmed ZIKV infection during pregnancy was associated with a 4% risk of microcephaly. Additionally, one-third of children showed at least one abnormality, predominantly identified in isolation. Studies examining antenatally ZIKV-exposed children without detectable abnormalities at birth reported conflicting neurodevelopmental results. Therefore, long-term follow-up studies involving pediatric cohorts with appropriate control groups are needed to address this knowledge gap. We recognize the crucial role of a national network of scientists collaborating with international research institutions in understanding the lifelong consequences of congenital ZIKV infection. Additionally, we highlight the need to provide sustainable resources for research and development to reduce the risk of future Zika outbreaks.

Replication properties of a contemporary Zika virus from West Africa

Zika virus (ZIKV) has become a global health problem over the past decade due to the extension of the geographic distribution of the Asian/American genotype. Recent epidemics of Asian/American ZIKV have been associated with developmental disorders in humans. There is mounting evidence that African ZIKV may be associated with increased fetal pathogenicity necessitating to pay a greater attention towards currently circulating viral strains in sub-Saharan Africa. Here, we generated an infectious molecular clone GUINEA-18 of a recently transmitted human ZIKV isolate from West Africa, ZIKV-15555. The available infectious molecular clone MR766MC of historical African ZIKV strain MR766-NIID was used for a molecular clone-based comparative study. Viral clones GUINEA-18 and MR766MC were compared for their ability to replicate in VeroE6, A549 and HCM3 cell lines. There was a lower replication rate for GUINEA-18 associated with weaker cytotoxicity and reduced innate immune system activation compared with MR766MC. Analysis of chimeric viruses between viral clones stressed the importance of NS1 to NS4B proteins, with a particular focus of NS4B on GUINEA-18 replicative properties. ZIKV has developed strategies to prevent cytoplasmic stress granule formation which occurs in response to virus infection. GUINEA-18 was greatly efficient in inhibiting stress granule assembly in A549 cells subjected to a physiological stressor, with NS1 to NS4B proteins also being critical in this process. The impact of these GUINEA-18 proteins on viral replicative abilities and host-cell responses to viral infection raises the question of the role of nonstructural proteins in the pathogenicity of currently circulating ZIKV in sub-Saharan Africa.

Broad-Spectrum Antiviral Effect of Cannabidiol Against Enveloped and Nonenveloped Viruses

Introduction: Cannabidiol (CBD), the main non-psychoactive cannabinoid of the Cannabis sativa plant, is a powerful antioxidant compound that in recent years has increased interest due to causes effects in a wide range of biological functions. Zika virus (ZIKV) is a virus transmitted mainly by the Aedes aegypti mosquitoes, which causes neurological diseases, such as microcephaly and Guillain-Barre syndrome. Although the frequency of viral outbreaks has increased recently, no vaccinations or particular chemotherapeutic treatments are available for ZIKV infection. Objectives: The major aim of this study was to explore the in vitro antiviral activity of CBD against ZIKV, expanding also to other dissimilar viruses. Materials and Methods: Cell cultures were infected with enveloped and nonenveloped viruses and treated with non-cytotoxic concentrations of CBD and then, viral titers were determined. Additionally, the mechanism of action of the compound during ZIKV in vitro infections was studied. To study the possible immunomodulatory role of CBD, infected and uninfected Huh-7 cells were exposed to 10 μM CBD during 48 h and levels of interleukins 6 and 8 and interferon-beta (IFN-β) expression levels were measured. On the other hand, the effect of CBD on cellular membranes was studied. For this, an immunofluorescence assay was performed, in which cell membranes were labeled with wheat germ agglutinin. Finally, intracellular cholesterol levels were measured. Results: CBD exhibited a potent antiviral activity against all the tested viruses in different cell lines with half maximal effective concentration values (CE50) ranging from 0.87 to 8.55 μM. Regarding the immunomodulatory effect of CBD during ZIKV in vitro infections, CBD-treated cells exhibited significantly IFN-β increased levels, meanwhile, interleukins 6 and 8 were not induced. Furthermore, it was determined that CBD affects cellular membranes due to the higher fluorescence intensity that was observed in CBD-treated cells and lowers intracellular cholesterol levels, thus affecting the multiplication of ZIKV and other viruses. Conclusions: It was demonstrated that CBD inhibits structurally dissimilar viruses, suggesting that this phytochemical has broad-spectrum antiviral effect, representing a valuable alternative in emergency situations during viral outbreaks, like the one caused by severe acute respiratory syndrome coronavirus 2 in 2020.

High-Risk Areas for Congenital Zika Syndrome in Rio de Janeiro: Spatial Cluster Detection

Brazil reported 18,282 suspected congenital Zika syndrome (CZS) cases up to 2018 and accounts for 61.4% of the total reported Zika cases in the Americas in the period. To detect high-risk areas for children with CZS in the city of Rio de Janeiro, we used cluster detection and thematic maps. We analyzed data using a Poisson model in Satscan 10.1.3 software. We also analyzed the records of children with CZS from 2015 to 2016 to describe the clinical and epidemiological maternal and child profile, as well as live births in 2016 and the social development index (SDI) by neighborhood. In 2015 and 2016, the incidence rates of CZS were 8.84 and 46.96 per 100,000 live births in the city, respectively. Severe congenital findings such as microcephaly and brain damage, osteoarticular impairment, ocular abnormalities, and hearing loss were observed in 47 children. The spatial distribution of CZS was concentrated in the north and west zones in heterogeneous neighborhoods. The neighborhoods with the highest occurrence of CZS cases were found to have the worst SDIs. Stascan detected three spatial clusters in the north zone, where the SDI is lower. The clusters presented high relative risks for CZS (7.86, 1.46, and 2.08), although they were not statistically significant. Our findings highlight a higher occurrence of CZS in areas with less favorable socioeconomic conditions.

Multiomics Approach Reveals Serum Biomarker Candidates for Congenital Zika Syndrome

The Zika virus (ZIKV) can be vertically transmitted, causing congenital Zika syndrome (CZS) in fetuses. ZIKV infection in early gestational trimesters increases the chances of developing CZS. This syndrome involves several pathologies with a complex diagnosis. In this work, we aim to identify biological processes and molecular pathways related to CZS and propose a series of putative protein and metabolite biomarkers for CZS prognosis in early pregnancy trimesters. We analyzed serum samples of healthy pregnant women and ZIKV-infected pregnant women bearing nonmicrocephalic and microcephalic fetuses. A total of 1090 proteins and 512 metabolites were identified by bottom-up proteomics and untargeted metabolomics, respectively. Univariate and multivariate statistical approaches were applied to find CZS differentially abundant proteins (DAP) and metabolites (DAM). Enrichment analysis (i.e., biological processes and molecular pathways) of the DAP and the DAM allowed us to identify the ECM organization and proteoglycans, amino acid metabolism, and arachidonic acid metabolism as CZS signatures. Five proteins and four metabolites were selected as CZS biomarker candidates. Serum multiomics analysis led us to propose nine putative biomarkers for CZS prognosis with high sensitivity and specificity.

Perinatal dengue and Zika virus cross-sectional seroprevalence and maternal-fetal outcomes among El Salvadoran women presenting for labor-and-delivery

BACKGROUND

Despite maternal flavivirus infections' linkage to severe maternal and fetal outcomes, surveillance during pregnancy remains limited globally. Further complicating maternal screening for these potentially teratogenic pathogens is the overwhelming subclinical nature of acute infection. This study aimed to understand perinatal and neonatal risk for poor health outcomes associated with flaviviral infection during pregnancy in El Salvador.

METHODS

Banked serologic samples and clinical results obtained from women presenting for labor and delivery at a national referent hospital in western El Salvador March to September 2022 were used for this study. 198 samples were screened for dengue and Zika virus IgM, and statistical analyses analyzed demographic and clinical outcome associations with IgM positivity.

RESULTS

This serosurvey revealed a high rate of maternal flavivirus infection-24.2% of women presenting for labor and delivery were dengue or Zika virus IgM positive, suggesting potential infection within pregnancy. Specifically, 20.2% were Zika virus IgM positive, 1.5% were dengue virus IgM positive, and 2.5% were both dengue and Zika virus IgM positive. Women whose home had received mosquito abatement assistance within the last year by the ministry of health were 70% less likely to test IgM positive (aOR = 0.30, 95%CI: 0.10, 0.83). Further, statistical geospatial clustering revealed transmission foci in six primary municipalities. Pregnancy complications and poor birth outcomes were noted among the dengue and/or Zika virus maternal infection group, although these outcomes were not statistically different than the seronegative group. None of the resulting neonates born during this study were diagnosed with congenital Zika syndrome.

CONCLUSIONS

The high rate of Zika virus detected among pregnant women and the lack of Zika-specific neonatal outcomes monitoring during a non-outbreak year highlights the need for continued surveillance in Central America and among immigrant mothers presenting for childbirth from these countries. As changing climatic conditions continue to expand the range of the disease vector, asymptomatic screening programs could be vital to early identification of outbreaks and clinical management of cases.

Neuroinflammation, blood-brain barrier dysfunction, hippocampal atrophy and delayed neurodevelopment: Contributions for a rat model of congenital Zika syndrome

The congenital Zika syndrome (CZS) has been characterized as a set of several brain changes, such as reduced brain volume and subcortical calcifications, in addition to cognitive deficits. Microcephaly is one of the possible complications found in newborns exposed to Zika virus (ZIKV) during pregnancy, although it is an impacting clinical sign. This study aimed to investigate the consequences of a model of congenital ZIKV infection by evaluating the histopathology, blood-brain barrier, and neuroinflammation in pup rats 24 h after birth, and neurodevelopment of the offspring. Pregnant rats were inoculated subcutaneously with ZIKV-BR at the dose 1 × 107 plaque-forming unit (PFU mL-1) of ZIKV isolated in Brazil (ZIKV-BR) on gestational day 18 (G18). A set of pups, 24 h after birth, was euthanized. The brain was collected and later evaluated for the histopathology of brain structures through histological analysis. Additionally, analyses of the blood-brain barrier were conducted using western blotting, and neuroinflammation was assessed using ELISA. Another set of animals was evaluated on postnatal days 3, 6, 9, and 12 for neurodevelopment by observing the developmental milestones. Our results revealed hippocampal atrophy in ZIKV animals, in addition to changes in the blood-brain barrier structure and pro-inflammatory cytokines expression increase. Regarding neurodevelopment, a delay in important reflexes during the neonatal period in ZIKV animals was observed. These findings advance the understanding of the pathophysiology of CZS and contribute to enhancing the rat model of CZS.

Oral conditions of children with microcephaly associated with congenital Zika syndrome: a cross-sectional study

The aim of the present study was to compare the oral conditions of children with congenital Zika syndrome (CZS)-associated microcephaly, non-CZS-associated microcephaly, and normotypical children, as well as to characterize their sociodemographic aspects and medical history. A paired cross-sectional study was carried out on 14 children with CZS-associated microcephaly and 24 age-matched controls, in Belo Horizonte, in southeastern Brazil. Children's oral conditions were assessed: dental caries experience (dmft/DMFT indices); developmental defects of enamel (DDE) index; dental anomalies; mucosal changes; lip sealing, and malocclusion (overjet, overbite, and/or posterior crossbite alterations). The quality of oral hygiene was analyzed by the simplified oral hygiene index. The children's mothers also answered a questionnaire about sociodemographic and medical history data. The variables were analyzed descriptively. Female participants were more prevalent (60.5%), and the mean age of the participants was 4.9 years (±1.4) (range: 2-8 years) and 92.1% of their exhibited some oral condition. All participants with CZS-associated microcephaly showed absence of lip sealing and had malocclusion (100.0%). When compared to the other groups, children with CZS had a higher percentage of dental anomalies (35.7%), mucosal changes (71.4%), and unsatisfactory oral hygiene (64.3%). In a sample composed mainly of female participants aged less than 5 years, the prevalence of oral conditions and unsatisfactory oral hygiene was higher in the group with CZS-associated microcephaly, followed by the group with non-CZS-associated microcephaly. Normotypical children had the highest percentage of dental caries experience.

Milk Antiviral Proteins and Derived Peptides against Zoonoses

Milk is renowned for its nutritional richness but also serves as a remarkable reservoir of bioactive compounds, particularly milk proteins and their derived peptides. Recent studies have showcased several robust antiviral activities of these proteins, evidencing promising potential within zoonotic viral diseases. While several publications focus on milk's bioactivities, antiviral peptides remain largely neglected in reviews. This knowledge is critical for identifying novel research directions and analyzing potential nutraceuticals within the One Health context. Our review aims to gather the existing scientific information on milk-derived antiviral proteins and peptides against several zoonotic viral diseases, and their possible mechanisms. Overall, in-depth research has increasingly revealed them as a promising and novel strategy against viruses, principally for those constituting a plausible pandemic threat. The underlying mechanisms of the bioactivity of milk's proteins include inhibiting viral entry and attachment to the host cells, blocking replication, or even viral inactivation via peptide-membrane interactions. Their marked versatility and effectiveness stand out compared to other antiviral peptides and can support future research and development in the post-COVID-19 era. Overall, our review helps to emphasize the importance of potentially effective milk-derived peptides, and their significance for veterinary and human medicines, along with the pharmaceutical, nutraceutical, and dairy industry.

Microcephaly in South Brazil: Are cases of Congenital Zika Syndrome increasing in recent years?

Northeast Brazil was the first region to detect a significant increase in babies born with microcephaly associated with prenatal zika virus infection in 2015. Rio Grande do Sul (RS) state was less impacted due to the temperate climate preventing the spread of the vector. This study investigated the prevalence and etiology of congenital microcephaly in RS in two different periods. This cross-sectional descriptive study included all live births with congenital microcephaly in RS from 2015 to 2022. Cases were divided into two groups: P1 "outbreak" (2015-16); and P2 "endemic" (2017-22). There were 58 cases of microcephaly (3.8/10,000) in P1 and 148 (1.97/10,000) in P2. Congenital Zika Virus infection was the etiology in 5.2% (n=3) in P1 and 6.7% (n=10) in P2. In conclusion, although the ZIKV outbreak in Brazil has receded, RS remains an area of concern, with a possible slight increase of live births with microcephaly secondary to ZIKV prenatal infection relative to the number of cases due to congenital infections. The broader distribution of the vector Aedes aegypti with warmer temperatures in our state might be linked to the increase in recent years. This study can be an alert to other regions of temperate or subtropical climates.

Roles of NS1 Protein in Flavivirus Pathogenesis

Flaviviruses such as dengue, Zika, and West Nile viruses are highly concerning pathogens that pose significant risks to public health. The NS1 protein is conserved among flaviviruses and is synthesized as a part of the flavivirus polyprotein. It plays a critical role in viral replication, disease progression, and immune evasion. Post-translational modifications influence NS1's stability, secretion, antigenicity, and interactions with host factors. NS1 protein forms extensive interactions with host cellular proteins allowing it to affect vital processes such as RNA processing, gene expression regulation, and cellular homeostasis, which in turn influence viral replication, disease pathogenesis, and immune responses. NS1 acts as an immune evasion factor by delaying complement-dependent lysis of infected cells and contributes to disease pathogenesis by inducing endothelial cell damage and vascular leakage and triggering autoimmune responses. Anti-NS1 antibodies have been shown to cross-react with host endothelial cells and platelets, causing autoimmune destruction that is hypothesized to contribute to disease pathogenesis. However, in contrast, immunization of animal models with the NS1 protein confers protection against lethal challenges from flaviviruses such as dengue and Zika viruses. Understanding the multifaceted roles of NS1 in flavivirus pathogenesis is crucial for effective disease management and control. Therefore, further research into NS1 biology, including its host protein interactions and additional roles in disease pathology, is imperative for the development of strategies and therapeutics to combat flavivirus infections successfully. This Review provides an in-depth exploration of the current available knowledge on the multifaceted roles of the NS1 protein in the pathogenesis of flaviviruses.

Go Zika Go: feasibility study with modified motorized ride-on cars for the mobility of children with Congenital Zika Syndrome (CZS)

PURPOSE

To explore the feasibility of an intervention using modified ride-on cars in terms of acceptability and potential changes in goal attainment, mobility, social function, and participation of children with Congenital Zika Syndrome (CZS).

MATERIALS AND METHODS

A pre- and post-intervention feasibility study was conducted with children with CZS, levels IV and V of the Gross Motor Function Classification System (GMFCS). The intervention consisted of 12 weeks of training (3 times a week for 40 min per session) and 4 weeks of follow-up. The primary outcomes included adherence, satisfaction, and learning in mobility. Secondary outcomes encompassed goal attainment, mobility, social/cognitive function, and participation. Descriptive statistics were performed. To explore potential individual changes with the intervention, Wilcoxon test was used to analyze Pediatric Evaluation of Disability Inventory - Computer Adaptive Test (PEDI-CAT) data and Young Children's Participation and Environment Measure (YC-PEM)/Participation and Environment Measure for Children and Youth (PEM-CY), along with standard error measurements of the PEDI-CAT domains.

RESULTS

Four children participated (median age 4.75 years; two females: three at level V on the GMFCS). Adherence was 75% of the total intervention time, and family members reported being satisfied or very satisfied. Children showed gains in learning the use of the modified ride-on cars and an increase in goal attainment after the intervention. Individual changes were observed in the PEDI-CAT domains (mobility and social/cognitive), but there were no significant changes in participation outcomes.

CONCLUSIONS

Children with CZS at GMFCS levels IV and V can learn to use motorized ride-on cars, attainment goals, and experience satisfaction.

Insight into the Natural Biomolecules (BMs): Promising Candidates as Zika Virus Inhibitors

Zika virus (ZIKV) is among the relatively new infectious disease threats that include SARS-CoV-2, coronavirus, monkeypox (Mpox) virus, etc. ZIKV has been reported to cause severe health risks to the fetus. To date, satisfactory treatment is still not available for the treatment of ZIKV infection. This review examines the last five years of work using natural biomolecules (BMs) to counteract the ZIKV through virtual screening and in vitro investigations. Virtual screening has identified doramectin, pinocembrin, hesperidins, epigallocatechin gallate, pedalitin, and quercetin as potentially active versus ZIKV infection. In vitro, testing has shown that nordihydroguaiaretic acid, mefloquine, isoquercitrin, glycyrrhetinic acid, patentiflorin-A, rottlerin, and harringtonine can reduce ZIKV infections in cell lines. However, in vivo, testing is limited, fortunately, emetine, rottlerin, patentiflorin-A, and lycorine have shown in vivo anti- ZIKV potential. This review focuses on natural biomolecules that show a particularly high selective index (>10). There is limited in vivo and clinical trial data for natural BMs, which needs to be an active area of investigation. This review aims to compile the known reference data and discuss the barriers associated with discovering and using natural BM agents to control ZIKV infection.

Congenital Zika Virus Syndrome: Microcephaly and Orofacial Anomalies

The progressive reappearance of Zika virus (ZIKV) infections since October 2013 and its circulation in >70 countries and territories (from French Polynesia to Brazil and other countries in the Americas, with sporadic spread in Europe and the East) has long been reported as a global public health emergency. ZIKV is a virus transmitted by arthropods (arboviruses), mainly by Aedes mosquitoes. ZIKV can also be transmitted to humans through mechanisms other than vector infection such as sexual intercourse, blood transfusions, and mother-to-child transmission. The latter mode of transmission can give rise to a severe clinical form called congenital Zika syndrome (CZS), which can result in spontaneous abortion or serious pathological alterations in the fetus such as microcephaly or neurological and orofacial anomalies. In this study, beside a succinct overview of the etiological, microbiological, and epidemiological aspects and modes of transmission of Zika virus infections, we have focused our attention on the pathogenetic and histopathological aspects in pregnancy and the pathogenetic and molecular mechanisms that can determine microcephaly, and consequently the clinical alterations, typical of the fetus and newborns, in a subject affected by CZS.

Rehabilitation Practices Delivered by Physical and Occupational Therapists to Brazilian Children With Congenital Zika Syndrome: A Cross-Sectional Study

INTRODUCTION

Congenital Zika syndrome (CZS) is a health condition that has affected the development of thousands of children in Brazil. Because it is a new condition, its understanding is an ongoing process. Therefore, it is important to know the rehabilitation interventions being delivered to improve the functioning of these children. We aimed to describe the practices of physical therapists (PTs) and occupational therapists (OTs) who provide follow-up care for children with CZS in Brazil.

METHODS

This cross-sectional study included PTs and OTs who assist children with CZS in Brazil. An online questionnaire was used to verify the participants' personal characteristics and professional work environment, as well as the rehabilitation programs they implemented in Brazil for children with CZS. Data were analyzed using descriptive statistics.

RESULTS

A total of 116 professionals (79 PT and 37 OT) who work mainly in public health services (81.9%) participated in the study. Of these, 24.1% plan interventions based on reading scientific articles, 66.4% did not report using the biopsychosocial model, 52.6% do not perform any assessments before starting an intervention, 31.9% use neurodevelopmental treatment, and 22.4% use sensorimotor stimulation interventions. The majority of the interventions are delivered 1 to 2 times a week, lasting up to 1 hour.

CONCLUSIONS

Professional training and knowledge translation strategies are needed to implement evidence-based practices and improve the quality of rehabilitation programs for Brazilian children with CZS.

Insights into Zika Virus Pathogenesis and Potential Therapeutic Strategies

Zika virus (ZIKV) has emerged as a significant public health threat, reaching pandemic levels in 2016. Human infection with ZIKV can manifest as either asymptomatic or as an acute illness characterized by symptoms such as fever and headache. Moreover, it has been associated with severe neurological complications in adults, including Guillain-Barre syndrome, and devastating fetal abnormalities, like microcephaly. The primary mode of transmission is through Aedes spp. mosquitoes, and with half of the world's population residing in regions where Aedes aegypti, the principal vector, thrives, the reemergence of ZIKV remains a concern. This comprehensive review provides insights into the pathogenesis of ZIKV and highlights the key cellular pathways activated upon ZIKV infection. Additionally, we explore the potential of utilizing microRNAs (miRNAs) and phytocompounds as promising strategies to combat ZIKV infection.

Serological investigation of vaccine-induced antibodies for measles, rubella, and yellow fever viruses in children vertically exposed to Zika virus or with down syndrome

Background

Vaccination schedules, as well as their effectiveness and contraindications, need to be evaluated regularly, especially in specific situations. Congenital Zika Syndrome (CZS) is a severe condition that results in extensive functional and neurological impairment of fetuses and newborns due to Zika virus tropism for fetal neural progenitor cells. Down Syndrome (DS) is the leading genetic cause of intellectual disability. The immune impairment in DS has already been described, but little is known about the immune response of CZS children. Thus, CZS and DS are specific conditions that can be considered for a reassessment of the available immunizations. Here, we carried out serological analyses of attenuated vaccines-induced antibodies for measles, rubella, and yellow fever viruses in children aged 2-7, grouped into asymptomatic controls, DS children, and CZS children.

Methods

Plasma samples were taken, and vaccination records were compiled during clinical follow-up. Enzymatic immunoassays for quantifying anti-measles and anti-rubella IgG were performed to assess the response to the Measles, Mumps, and Rubella (MMR) vaccine. Plaque Reduction Neutralization Test (PRNT) was performed to investigate neutralizing antibodies in response to the Brazilian vaccine strain of yellow fever (YF-17DD).

Results

We highlight similar levels of anti-measles IgG and neutralizing antibodies for YF-17DD among CZS, DS, and asymptomatic children, although low positivity of measles data was seen in the three groups. In DS children, the 2-4-year-old group had an increased level of anti-measles IgG compared to the older group of children aged five to seven years. Lower anti-rubella IgG levels were observed in CZS and DS children compared to asymptomatic children. For anti-rubella IgG, the good performance of vaccination in asymptomatic children is due to younger ones rather than older ones.

Conclusions

There were no reports of adverse events after the use of the MMR and YF-17DD indicating that CZS and DS could continue to receive these vaccines, but our data draws attention to the necessity of monitoring the vaccination response in CZS and DS children over time and the possible need to adhere to national measles vaccination campaigns. Scientific research needs to continue to help develop appropriate CZS and DS health guidelines.

Nanoluciferase Reporter Zika Viruses as Tools for Assessing Infection Kinetics and Antibody Potency

Zika virus (ZIKV) has become endemic in multiple tropical and subtropical regions and has the potential to become widespread in countries with limited prior exposure to this infection. One of the most concerning sequelae of ZIKV infection is the teratogenic effect on the developing fetus, with the mechanisms of viral spread to and across the placenta remaining largely unknown. Although vaccine trials and prophylactic or therapeutic treatments are being studied, there are no approved treatments or vaccines for ZIKV. Appropriate tests, including potency and in vivo assays to assess the safety and efficacy of these modalities, can greatly aid both the research of the pathophysiology of the infection and the development of anti-ZIKV therapeutics. Building on previous work, we tested reporter ZIKV variants that express nanoluciferase in cell culture and in vivo assays. We found that these variants can propagate in cells shown to be susceptible to the widely used clinical isolate PRVABC59, including Vero and human placenta cell lines. When used in neutralization assays with bioluminescence as readout, these variants gave rise to neutralization curves similar to those produced by PRVABC59, while being better suited for performing high-throughput assays. In addition, the engineered reporter variants can be useful research tools when used in other in vitro and in vivo assays, as we illustrated in transcytosis experiments and a pilot study in guinea pigs.

Lipid droplets in Zika neuroinfection: Potential targets for intervention?

Lipid droplets (LD) are evolutionarily conserved lipid-enriched organelles with a diverse array of cell- and stimulus-regulated proteins. Accumulating evidence demonstrates that intracellular pathogens exploit LD as energy sources, replication sites, and part of the mechanisms of immune evasion. Nevertheless, LD can also favor the host as part of the immune and inflammatory response to pathogens. The functions of LD in the central nervous system have gained great interest due to their presence in various cell types in the brain and for their suggested involvement in neurodevelopment and neurodegenerative diseases. Only recently have the roles of LD in neuroinfections begun to be explored. Recent findings reveal that lipid remodelling and increased LD biogenesis play important roles for Zika virus (ZIKV) replication and pathogenesis in neural cells. Moreover, blocking LD formation by targeting DGAT-1 in vivo inhibited virus replication and inflammation in the brain. Therefore, targeting lipid metabolism and LD biogenesis may represent potential strategies for anti-ZIKV treatment development. Here, we review the progress in understanding LD functions in the central nervous system in the context of the host response to Zika infection.

Neurodevelopmental outcomes in congenital and perinatal infections

PURPOSE OF REVIEW

Congenital infections are a major cause of childhood multidomain neurodevelopmental disabilities. They contribute to a range of structural brain abnormalities that can cause severe neurodevelopmental impairment, cerebral palsy, epilepsy, and neurosensory impairments. New congenital infections and global viral pandemics have emerged, with some affecting the developing brain and causing neurodevelopmental concerns. This review aims to provide current understanding of fetal infections and their impact on neurodevelopment.

RECENT FINDINGS

There are a growing list of congenital infections causing neurodevelopmental issues, including cytomegalovirus, Zika virus, syphilis, rubella, lymphocytic choriomeningitis virus, and toxoplasmosis. Fetal exposure to maternal SARS-CoV-2 may also pose risk to the developing brain and impact neurodevelopmental outcomes, although studies have conflicting results. As Zika virus was a recently identified congenital infection, there are several new reports on child neurodevelopment in the Caribbean and Central and South America. For many congenital infections, children with in-utero exposure, even if asymptomatic at birth, may have neurodevelopmental concerns manifest over time.

SUMMARY

Congenital infections should be considered in the differential diagnosis of a child with neurodevelopmental impairments. Detailed pregnancy history, exposure risk, and testing should guide diagnosis and multidisciplinary evaluation. Children with congenital infections should have long-term follow-up to assess for neurodevelopmental delays and other neurosensory impairments. Children with confirmed delays or high-risk should be referred for rehabilitation therapies.

Sleep in children from northeastern Brazil with congenital Zika syndrome: assessment using polysomnography

STUDY OBJECTIVES

We performed this study to describe the characteristics of sleep in children with congenital Zika syndrome through polysomnographic assessment.

METHODS

Polysomnography with neurological setup and capnography was performed. Respiratory events were scored according to American Academy of Sleep Medicine criteria. Children were classified based on neuroclinical examination as having corticospinal plus neuromuscular abnormalities or exclusively corticospinal abnormalities. Neuroradiological classification was based on imaging exams, with children classed as having supratentorial plus infratentorial abnormalities or exclusively supratentorial abnormalities.

RESULTS

Of 65 children diagnosed with congenital Zika syndrome, sleep apnea was present in 23 children (35.4%), desaturation in 26 (40%), and snoring in 13 (20%). The most prevalent apnea type was central in 15 children (65.2%), followed by obstructive apnea in 5 (21.7%) and mixed type in 3 (13%). The average of the lowest saturation recorded was slightly below normal (89.1 ± 4.9%) and the mean partial pressure of end-tidal carbon dioxide value was normal. Periodic leg movements were present in 48 of 65 children. Lower ferritin levels were observed in 84.6% of children. Palatine and pharyngeal tonsils (adenoids) were small in most children and not associated with the presence of obstructive apnea. Ventriculomegaly and subcortical and nucleus calcification were the most frequent neuroimaging findings. Supratentorial and infratentorial anomalies were present in 26.7% (16 of 60) and exclusively supratentorial changes in 73.3% (44 of 60). In the neuroclinical classification, isolated corticospinal changes were more frequent and the mean peak in capnography was lower in this group. There was no difference regarding the presence of apnea for children in the neuroclinical and neuroradiological classification groups.

CONCLUSIONS

Sleep disorders were frequent in children with congenital Zika syndrome, with central sleep apnea being the main finding.

CITATION

Brandão Marquis V, de Oliveira Melo A, Pradella-Hallinan M, et al. Sleep in children from northeastern Brazil with congenital Zika syndrome: assessment using polysomnography. J Clin Sleep Med. 2023;19(10):1759-1767.

Heparin Precursors with Reduced Anticoagulant Properties Retain Antiviral and Protective Effects That Potentiate the Efficacy of Sofosbuvir against Zika Virus Infection in Human Neural Progenitor Cells

Zika virus (ZIKV) infection during pregnancy can result in severe birth defects, such as microcephaly, as well as a range of other related health complications. Heparin, a clinical-grade anticoagulant, is shown to protect neural progenitor cells from death following ZIKV infection. Although heparin can be safely used during pregnancy, it retains off-target anticoagulant effects if directly employed against ZIKV infection. In this study, we investigated the effects of chemically modified heparin derivatives with reduced anticoagulant activities. These derivatives were used as experimental probes to explore the structure-activity relationships. Precursor fractions of porcine heparin, obtained during the manufacture of conventional pharmaceutical heparin with decreased anticoagulant activities, were also explored. Interestingly, these modified heparin derivatives and precursor fractions not only prevented cell death but also inhibited the ZIKV replication of infected neural progenitor cells grown as neurospheres. These effects were observed regardless of the specific sulfation position or overall charge. Furthermore, the combination of heparin with Sofosbuvir, an antiviral licensed for the treatment of hepatitis C (HCV) that also belongs to the same Flaviviridae family as ZIKV, showed a synergistic effect. This suggested that a combination therapy approach involving heparin precursors and Sofosbuvir could be a potential strategy for the prevention or treatment of ZIKV infections.

Low CCL2 and CXCL8 Production and High Prevalence of Allergies in Children with Microcephaly Due to Congenital Zika Syndrome

Congenital Zika Syndrome (CZS) is associated with an increased risk of microcephaly in affected children. This study investigated the peripheral dysregulation of immune mediators in children with microcephaly due to CZS. Gene expression quantified by qPCR in whole blood samples showed an increase in IFNγ and IL-13 transcripts in children affected with microcephaly compared to the control group. The microcephaly group exhibited significantly decreased CCL2 and CXCL8 levels in serum, quantified by CBA assay. An allergic profile questionnaire revealed a high prevalence of allergies in the microcephaly group. In accordance, elevated serum IgE level measured by the Proquantum Immunoassay was observed in children affected with microcephaly compared to the control group. Altogether, these findings show a persistent systemic inflammation in children with microcephaly due to CZS and suggest a possible impairment in leukocyte migration caused by low production of CCL2 and CXCL8, in addition to high levels of IgE associated with high prevalence of allergies. The dysregulation of inflammatory genes and chemokines underscores the importance of understanding the immunological characteristics of CZS. Further investigation into the long-term consequences of systemic inflammation in these children is crucial for developing appropriate therapeutic strategies and tailored vaccination protocols.

Developing brain under renewed attack: viral infection during pregnancy

Living in a globalized world, viral infections such as CHIKV, SARS-COV-2, and ZIKV have become inevitable to also infect the most vulnerable groups in our society. That poses a danger to these populations including pregnant women since the developing brain is sensitive to maternal stressors including viral infections. Upon maternal infection, the viruses can gain access to the fetus via the maternofetal barrier and even to the fetal brain during which factors such as viral receptor expression, time of infection, and the balance between antiviral immune responses and pro-viral mechanisms contribute to mother-to-fetus transmission and fetal infection. Both the direct pro-viral mechanisms and the resulting dysregulated immune response can cause multi-level impairment in the maternofetal and brain barriers and the developing brain itself leading to dysfunction or even loss of several cell populations. Thus, maternal viral infections can disturb brain development and even predispose to neurodevelopmental disorders. In this review, we discuss the potential contribution of maternal viral infections of three relevant relative recent players in the field: Zika, Chikungunya, and Severe Acute Respiratory Syndrome Coronavirus-2, to the impairment of brain development throughout the entire route.

Adenovirus vector produced Zika virus-like particles induce a long-lived neutralising antibody response in mice

Countermeasures against Zika virus (ZIKV) epidemics are urgently needed. In this study we generated a ZIKV virus-like particle (VLP) based vaccine candidate and assessed the immunogenicity of these particles in mice. The ZIKV-VLPs were morphologically similar to ZIKV by electron microscopy and were recognized by anti-Flavivirus neutralising antibodies. We observed that a single dose of unadjuvanted ZIKV-VLPs, or inactivated ZIKV, generated an immune response that lasted over 6 months, but did not neutralize ZIKV infection of cells in vitro. However, when we co-administered the ZIKV VLPs with either Aluminium hydroxide (Alhydrogel®; Alum), AddaVax or Pam₂Cys we observed that Alum was the most effective in a single dose regime, since it not only produced antibodies that neutralized the virus, but also generated a greater number of antigen-specific memory B cells. We additionally observed that the generation of the neutralising antibodies persisted for up to 6 months. Our results suggest that a single dose ZIKV VLPs could be a suitable single dose vaccine candidate for use in outbreak settings.

Viruses and autism: A Bi-mutual cause and effect

Autism spectrum disorder (ASD) is a group of heterogeneous, multi-factorial, neurodevelopmental disorders resulting from genetic and environmental factors interplay. Infection is a significant trigger of autism, especially during the critical developmental period. There is a strong interplay between the viral infection as a trigger and a result of ASD. We aim to highlight the mutual relationship between autism and viruses. We performed a thorough literature review and included 158 research in this review. Most of the literature agreed on the possible effects of the viral infection during the critical period of development on the risk of developing autism, especially for specific viral infections such as Rubella, Cytomegalovirus, Herpes Simplex virus, Varicella Zoster Virus, Influenza virus, Zika virus, and severe acute respiratory syndrome coronavirus 2. Viral infection directly infects the brain, triggers immune activation, induces epigenetic changes, and raises the risks of having a child with autism. At the same time, there is some evidence of increased risk of infection, including viral infections in children with autism, due to lots of factors. There is an increased risk of developing autism with a specific viral infection during the early developmental period and an increased risk of viral infections in children with autism. In addition, children with autism are at increased risk of infection, including viruses. Every effort should be made to prevent maternal and early-life infections and reduce the risk of autism. Immune modulation of children with autism should be considered to reduce the risk of infection.

Comparative Infections of Zika, Dengue, and Yellow Fever Viruses in Human Cytotrophoblast-Derived Cells Suggest a Gating Role for the Cytotrophoblast in Zika Virus Placental Invasion

The Zika virus (ZIKV) is teratogenic and considered a TORCH pathogen (toxoplasmosis [Toxoplasma gondii], rubella, cytomegalovirus, herpes simplex virus [HSV], and other microorganisms capable of crossing the blood-placenta barrier). In contrast, the related flavivirus dengue virus (DENV) and the attenuated yellow fever virus vaccine strain (YFV-17D) are not. Understanding the mechanisms used by ZIKV to cross the placenta is necessary. In this work, parallel infections with ZIKV of African and Asian lineages, DENV, and YFV-17D were compared for kinetics and growth efficiency, activation of mTOR pathways, and cytokine secretion profile using cytotrophoblast-derived HTR8 cells and monocytic U937 cells differentiated to M2 macrophages. In HTR8 cells, ZIKV replication, especially the African strain, was significantly more efficient and faster than DENV or YFV-17D. In macrophages, ZIKV replication was also more efficient, although differences between strains were reduced. Greater activation of the mTORC1 and mTORC2 pathways in HTR8 cells infected with ZIKV than with DENV or YFV-17D was observed. HTR8 cells treated with mTOR inhibitors showed a 20-fold reduction in ZIKV yield, versus 5- and 3.5-fold reductions for DENV and YFV-17D, respectively. Finally, infection with ZIKV, but not DENV or YFV-17D, efficiently inhibited the interferon (IFN) and chemoattractant responses in both cell lines. These results suggest a gating role for the cytotrophoblast cells in favoring entry of ZIKV, but not DENV and YFV-17D, into the placental stroma. IMPORTANCE Zika virus acquisition during pregnancy is associated with severe fetal damage. The Zika virus is related to dengue virus and yellow fever virus, yet fetal damage has not been related to dengue or inadvertent vaccination for yellow fever during pregnancy. Mechanisms used by the Zika virus to cross the placenta need to be deciphered. By comparing parallel infections of Zika virus strains belonging to the African and Asian lineages, dengue virus, and the yellow fever vaccine virus strain YFV-17D in placenta-derived cytotrophoblast cells and differentiated macrophages, evidence was found that Zika virus infections, especially by the African strains, were more efficient in cytotrophoblast cells than dengue virus or yellow fever vaccine virus strain infections. Meanwhile, no significant differences were observed in macrophages. Robust activation of the mTOR signaling pathways and inhibition of the IFN and chemoattractant response appear to be related to the better growth capacity of the Zika viruses in the cytotrophoblast-derived cells.

Monodelphis domestica as a Fetal Intra-Cerebral Inoculation Model for Zika Virus Pathogenesis

Monodelphis domestica (the laboratory opossum) is a marsupial native to South America. At birth, these animals are developmentally equivalent to human embryos at approximately 5 weeks of gestation, which, when coupled with other characteristics including the size of the animals, the development of a robust immune system during juvenile development, and the relative ease of experimental manipulation, have made M. domestica a valuable model in many areas of biomedical research. However, their suitability as models for infectious diseases, especially neurotropic viruses such as Zika virus (ZIKV), is currently unknown. Here, we describe the replicative effects of ZIKV using a fetal intra-cerebral model of inoculation. Using immunohistology and in situ hybridization, we found that opossum embryos and fetuses are susceptible to infection by ZIKV administered intra-cerebrally, that the infection persists, and that viral replication results in neural pathology and may occasionally result in global growth restriction. These results demonstrate the utility of M. domestica as a new animal model for investigating ZIKV infection in vivo and facilitate further inquiry into viral pathogenesis, particularly for those viruses that are neurotropic, that require a host with the ability to sustain sustained viremia, and/or that may require intra-cerebral inoculations of large numbers of embryos or fetuses.

Risk of adverse pregnancy and infant outcomes associated with prenatal Zika virus infection: a post-epidemic cohort in Central-West Brazil

This study aimed to estimate the risks of adverse infant outcomes in the first year of life related to prenatal Zika virus (ZIKV) exposure. A prospective cohort of pregnant women with rash was recruited in Central-West Brazil in a post-epidemic period (January 2017 to April 2019). We evaluated participants' medical histories and performed ZIKV diagnostic testing using molecular (reverse transcription polymerase chain reaction [RT-PCR]) and serologic (immunoglobulin [Ig]M and plaque reduction neutralization tests [PRNT90]) assays. The ZIKV-positive group included both RT-PCR-confirmed cases as well as IgM and/or PRNT90-positive probable cases. Children were evaluated at birth and in the first 12 months of life. Transfontanellar ultrasound, central nervous system computed tomography, eye fundoscopy and retinography were performed. We estimated the absolute risk and 95% confidence interval (95% CI) of adverse infant outcomes among confirmed prenatally ZIKV-exposed children. Among 81 pregnant women with rash, 43 (53.1%) were ZIKV infected. The absolute risk of microcephaly among offspring of ZIKV-infected pregnant women was 7.0% (95% CI: 1.5-19.1), including the two cases of microcephaly detected prenatally and one detected postnatally. In total, 54.5% (95% CI: 39.8-68.7) of children in the ZIKV-exposed group had at least one ophthalmic abnormality, with the most frequent abnormalities being focal pigmentary mottling and chorioretinal atrophy or scarring. Our findings reinforce the importance of long-term monitoring of prenatally ZIKV-exposed children born apparently asymptomatic for Congenital Zika Syndrome.

Oral alterations in children with microcephaly associated to congenital Zika syndrome: A systematic review and meta-analyses

AIMS

To synthesize the oral alterations observed in children with microcephaly associated with congenital Zika virus syndrome (CZS), and to compare the oral alterations of these children to a normotypic healthy controls.

METHODS AND RESULTS

A search was performed in six electronic databases. Observational studies published that reported oral alterations in children with CZS were selected. Two authors independently extracted data, assessed study quality, using the Joanna Briggs Institute Critical Appraisal Checklist tools, and the certainty of evidence, using Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Twenty-one studies were included in this systematic review and meta-analysis. The pooled crude occurrence showed 88% of increased salivation (95%CI: 82%-94%), 83% of biofilm (95%CI: 75%-91%), and 73% of bruxism (95%CI: 52%-95%). Compared to normotypic controls, children with CZS-associated microcephaly had a higher chance to have difficulty in lip sealing (OR: 18.28; 95%CI: 1.42-235.91), inadequate lingual posture at rest (OR: 13.57; 95%CI: 4.24-43.44), and delayed eruption (OR: 12.92; 95%CI: 3.42-48.78), with very low certainty.

CONCLUSION

There are several oral alterations found among children with CZS-associated microcephaly. They are more prone to present some of these alterations, such as difficulty in lip sealing, although with very low certainty of evidence.

Growth Velocity and Nutritional Status in Children Exposed to Zika Virus during Pregnancy from Amazonas Cohort, Brazil

The high incidence of Zika virus (ZIKV) infection in the period of 2015–2016 in Brazil may have affected linear height growth velocity (GV) in children exposed in utero to ZIKV. This study describes the growth velocity and nutritional status based on the World Organization (WHO) standards of children exposed to ZIKV during pregnancy and followed up in a tertiary unit, a reference for tropical and infectious diseases in the Amazon. Seventy-one children born between March 2016 and June 2018 were monitored for anthropometric indices: z-score for body mass index (BMI/A); weight (W/A); height (H/A) and head circumference (HC/A); and growth velocity. The mean age at the last assessment was 21.1 months (SD ± 8.93). Four children had congenital microcephaly and severe neurological impairment. The other 67 were non-microcephalic children (60 normocephalic and 7 macrocephalic); of these; 24.2% (16 children) had neurological alterations, and 28.8% (19 children) had altered neuropsychomotor development. Seventeen (24.2%) children had inadequate GV (low growth velocity). The frequencies of low growth among microcephalic and non-microcephalic patients are 25% (1 of 4 children) and 23.9% (16 of 67 children); respectively. Most children had normal BMI/A values during follow-up. Microcephalic patients showed low H/A and HC/A throughout the follow-up, with a significant reduction in the HC/A z-score. Non-microcephalic individuals are within the regular ranges for H/A; HC/A; and W/A, except for the H/A score for boys. This study showed low growth velocity in children with and without microcephaly, highlighting the need for continuous evaluation of all children born to mothers exposed to ZIKV during pregnancy.

Arthropod-Borne Flaviviruses in Pregnancy

Flaviviruses are a diverse group of enveloped RNA viruses that cause significant clinical manifestations in the pregnancy and postpartum periods. This review highlights the epidemiology, pathophysiology, clinical features, diagnosis, and prevention of the key arthropod-borne flaviviruses of concern in pregnancy and the neonatal period-Zika, Dengue, Japanese encephalitis, West Nile, and Yellow fever viruses. Increased disease severity during pregnancy, risk of congenital malformations, and manifestations of postnatal infection vary widely amongst this virus family and may be quite marked. Laboratory confirmation of infection is complex, especially due to the reliance on serology for which flavivirus cross-reactivity challenges diagnostic specificity. As such, a thorough clinical history including relevant geographic exposures and prior vaccinations is paramount for accurate diagnosis. Novel vaccines are eagerly anticipated to ameliorate the impact of these flaviviruses, particularly neuroinvasive disease manifestations and congenital infection, with consideration of vaccine safety in pregnant women and children pivotal. Moving forward, the geographical spread of flaviviruses, as for other zoonoses, will be heavily influenced by climate change due to the potential expansion of vector and reservoir host habitats. Ongoing 'One Health' engagement across the human-animal-environment interface is critical to detect and responding to emergent flavivirus epidemics.

Causes of death in children with congenital Zika syndrome in Brazil, 2015 to 2018: A nationwide record linkage study

BACKGROUND

Children with congenital Zika syndrome (CZS) have severe damage to the peripheral and central nervous system (CNS), greatly increasing the risk of death. However, there is no information on the sequence of the underlying, intermediate, immediate, and contributing causes of deaths among these children. The aims of this study are describe the sequence of events leading to death of children with CZS up to 36 months of age and their probability of dying from a given cause, 2015 to 2018.

METHODS AND FINDINGS

In a population-based study, we linked administrative data on live births, deaths, and cases of children with CZS from the SINASC (Live Birth Information System), the SIM (Mortality Information System), and the RESP (Public Health Event Records), respectively. Confirmed and probable cases of CZS were those that met the criteria established by the Brazilian Ministry of Health. The information on causes of death was collected from death certificates (DCs) using the World Health Organization (WHO) DC template. We estimated proportional mortality (PM%) among children with CZS and among children with non-Zika CNS congenital anomalies (CA) by 36 months of age and proportional mortality ratio by cause (PMRc). A total of 403 children with confirmed and probable CZS who died up to 36 months of age were included in the study; 81.9% were younger than 12 months of age. Multiple congenital malformations not classified elsewhere, and septicemia unspecified, with 18 (PM = 4.5%) and 17 (PM = 4.2%) deaths, respectively, were the most attested underlying causes of death. Unspecified septicemia (29 deaths and PM = 11.2%) and newborn respiratory failure (40 deaths and PM = 12.1%) were, respectively, the predominant intermediate and immediate causes of death. Fetuses and newborns affected by the mother's infectious and parasitic diseases, unspecified cerebral palsy, and unspecified severe protein-caloric malnutrition were the underlying causes with the greatest probability of death in children with CZS (PMRc from 10.0 to 17.0) when compared to the group born with non-Zika CNS anomalies. Among the intermediate and immediate causes of death, pneumonitis due to food or vomiting and unspecified seizures (PMRc = 9.5, each) and unspecified bronchopneumonia (PMRc = 5.0) were notable. As contributing causes, fetus and newborn affected by the mother's infectious and parasitic diseases (PMRc = 7.3), unspecified cerebral palsy, and newborn seizures (PMRc = 4.5, each) were more likely to lead to death in children with CZS than in the comparison group. The main limitations of this study were the use of a secondary database without additional clinical information and potential misclassification of cases and controls.

CONCLUSION

The sequence of causes and circumstances involved in the deaths of the children with CZS highlights the greater vulnerability of these children to infectious and respiratory conditions compared to children with abnormalities of the CNS not related to Zika.

Neurology of Systemic Disease

Sex differences exist within the neurologic complications of systemic disease. To promote new avenues for prevention and develop novel therapeutics, we highlight the role of sex in differential outcomes to infectious disease and cardiac arrest and educate the reader in paraneoplastic presentations that may herald underlying malignancies in women.

Extracellular Vesicles Are Conveyors of the NS1 Toxin during Dengue Virus and Zika Virus Infection

Extracellular vesicles (EVs), produced during viral infections, are of emerging interest in understanding infectious processes and host-pathogen interactions. EVs and exosomes in particular have the natural ability to transport nucleic acids, proteins, and other components of cellular or viral origin. Thus, they participate in intercellular communication, immune responses, and infectious and pathophysiological processes. Some viruses are known to hijack the cell production and content of EVs for their benefit. Here, we investigate whether two pathogenic flaviviruses i.e., Zika Virus (ZIKV) and Dengue virus (DENV2) could have an impact on the features of EVs. The analysis of EVs produced by infected cells allowed us to identify that the non-structural protein 1 (NS1), described as a viral toxin, is associated with exosomes. This observation could be confirmed under conditions of overexpression of recombinant NS1 from each flavivirus. Using different isolation methods (i.e., exosome isolation kit, size exclusion chromatography, Polyethylene Glycol enrichment, and ELISA capture), we showed that NS1 was present as a dimer at the surface of excreted exosomes, and that this association could occur in the extracellular compartment. This finding could be of major importance in a physiological context. Indeed, this capacity of NS1 to address EVs and its implication in the pathophysiology during Dengue or Zika diseases should be explored. Furthermore, exosomes that have demonstrated a natural capacity to vectorize NS1 could serve as useful tools for vaccine development.

ZIKV: Epidemiology, infection mechanism and current therapeutics

The Zika virus (ZIKV) is a vector-borne flavivirus that has been detected in 87 countries worldwide. Outbreaks of ZIKV infection have been reported from various places around the world and the disease has been declared a public health emergency of international concern. ZIKV has two modes of transmission: vector and non-vector. The ability of ZIKV to vertically transmit in its competent vectors, such as Aedes aegypti and Aedes albopictus, helps it to cope with adverse conditions, and this could be the reason for the major outbreaks that occur from time to time. ZIKV outbreaks are a global threat and, therefore, there is a need for safe and effective drugs and vaccines to fight the virus. In more than 80% of cases, ZIKV infection is asymptomatic and leads to complications, such as microcephaly in newborns and Guillain–Barré syndrome (GBS) in adults. Drugs such as sofosbuvir, chloroquine, and suramin have been found to be effective against ZIKV infections, but further evaluation of their safety in pregnant women is needed. Although temoporfin can be given to pregnant women, it needs to be tested further for side effects. Many vaccine types based on protein, vector, DNA, and mRNA have been formulated. Some vaccines, such as mRNA-1325 and VRC-ZKADNA090-00-VP, have reached Phase II clinical trials. Some new techniques should be used for formulating and testing the efficacy of vaccines. Although there have been no recent outbreaks of ZIKV infection, several studies have shown continuous circulation of ZIKV in mosquito vectors, and there is a risk of re-emergence of ZIKV in the near future. Therefore, vaccines and drugs for ZIKV should be tested further, and safe and effective therapeutic techniques should be licensed for use during outbreaks.

The safety and immunogenicity of two Zika virus mRNA vaccine candidates in healthy flavivirus baseline seropositive and seronegative adults: the results of two randomised, placebo-controlled, dose-ranging, phase 1 clinical trials

BACKGROUND

Developing a safe and immunogenic vaccine against Zika virus remains an unmet medical need. We did two phase 1 studies that evaluated the safety and immunogenicity of two mRNA-based Zika virus vaccines (mRNA-1325 and mRNA-1893) in adults.

METHODS

Two randomised, placebo-controlled, dose-ranging, multicentre, phase 1 trials, one of mRNA-1325 (mRNA-1325 trial) and one of mRNA-1893 (mRNA-1893 trial), were done. For both studies, eligible participants were healthy adults (aged 18-49 years) who were flavivirus seronegative or flavivirus seropositive at baseline. Participants in the mRNA-1325 trial, which was done at three centres in the USA, were randomly assigned centrally (1:4), using a randomisation table, to the placebo group or one of three mRNA-1325 dose groups (10, 25, or 100 μg). All participants received two doses. The mRNA-1325 vaccine encoded the premembrane and envelope E structural proteins (prME) from a Micronesia 2007 Zika virus isolate. Participants in the mRNA-1893 trial, which was done at three centres in the USA and one centre in Puerto Rico, were randomly assigned (1:4) to the placebo group or one of four mRNA-1893 dose groups (10, 30, 100, or 250 μg) using centralised interactive response technology. All participants in the mRNA-1893 trial received dose one on day 1 and then dose two on day 29. The mRNA-1893 vaccine encoded the prME from the RIO-U1 Zika virus isolate. Safety was the primary outcome of each study, which was evaluated in the respective safety populations (mRNA-1325 trial: participants who received at least one dose and provided safety data; mRNA-1893 trial: participants who received at least one dose) and the solicited safety population (mRNA-1893 trial only: received at least 1 dose and contributed solicited adverse reaction data). Endpoints in both trials included solicited adverse reactions within 7 days after vaccination and unsolicited adverse events within 28 days after vaccination. The secondary outcome of both trials was immunogenicity assessed by Zika virus-specific neutralising antibodies (nAbs) in the per-protocol populations in either trial (participants with no major protocol deviations received full dose[s] of assigned dose level within the acceptable time window, had samples drawn within acceptable time window, and had prevaccination and corresponding post-vaccination serum samples for testing). These were descriptive studies, with no formal hypothesis testing in either trial. Both trials are registered with ClinicalTrials.gov, NCT03014089 (mRNA-1325 trial) and NCT04064905 (mRNA-1893 trial).

FINDINGS

The mRNA-1325 trial was done from Dec 14, 2016, to Aug 16, 2018. 90 participants were enrolled: 53 (59%) participants were women and 37 (41%) were men; 84 (93%) were White; and 74 (82%) were not Hispanic or Latino. All three dose levels of mRNA-1325 (10, 25, and 100 μg) were generally well tolerated, but the vaccine elicited poor Zika virus-specific nAb responses. At 28 days after dose two, geometric mean titres (GMTs) were highest for mRNA-1325 10 μg (10·3 [95% CI 5·9-18·2]). The mRNA-1893 trial was done from July 23, 2019, to March 22, 2021. 120 participants (70 [58%] women and 50 [42%] men) were enrolled, most participants were White (89 [74%]), and not Hispanic or Latino (91 [76%]). In the mRNA-1893 trial, solicited adverse reactions in participants who received a vaccine were mostly grade 1 or 2 and occurred more frequently at higher dose levels and after dose two. No participants withdrew due to an unsolicited treatment-emergent adverse event and most of these events were not treatment related. On day 57, all evaluated mRNA-1893 dose levels induced robust Zika virus-specific nAb responses, independent of flavivirus serostatus, that persisted until month 13. At day 57 in participants who were flavivirus seronegative, plaque reduction neutralisation titre test nAb GMTs were highest for mRNA-1893 100 μg (454·2 [330·0-619·6]); in participants who were flavivirus seropositive, GMTs were highest for mRNA-1893 10 μg (224·1 [43·5-1153·5]) and mRNA-1893 100 μg (190·5 [19·2-1887·2]).

INTERPRETATION

These findings support the continued development of mRNA-1893 against Zika virus, which was well tolerated at all evaluated dose levels and induced strong Zika virus-specific serum nAb responses after two doses, regardless of baseline flavivirus serostatus.

FUNDING

Biomedical Advanced Research and Development Authority and Moderna.

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.

Placental extracellular vesicles in maternal-fetal communication during pregnancy

For several years, a growing number of studies have highlighted the pivotal role of placental extracellular vesicles (EVs) throughout pregnancy. These membrane nanovesicles, heterogeneous in nature, composition and origin, are secreted by several trophoblastic cell types and are found in both the maternal and fetal compartments. They can be uptaken by recipient cells and drive a wide variety of physiological and pathological processes. In this review, we provide an overview of the different described roles of placental EVs in various aspects of normal pregnancy, from placenta establishment to maternal immune tolerance towards the fetus and protection against viral infections. In the second part, we present selected examples of pathological pregnancies in which placental EVs are involved, such as gestational diabetes mellitus, pre-eclampsia, and congenital infections. Since the abundance and/or composition of placental EVs is deregulated in maternal serum during pathological pregnancies, this makes them interesting candidates as non-invasive biomarkers for gestational diseases and opens a wide field of translational perspectives.

Heterogeneity of Zika virus exposure and outcome ascertainment across cohorts of pregnant women, their infants and their children: a metadata survey

OBJECTIVES

To support the Zika virus (ZIKV) Individual Participant Data (IPD) Consortium's efforts to harmonise and analyse IPD from ZIKV-related prospective cohort studies and surveillance-based studies of pregnant women and their infants and children; we developed and disseminated a metadata survey among ZIKV-IPD Meta-Analysis (MA) study participants to identify and provide a comprehensive overview of study-level heterogeneity in exposure, outcome and covariate ascertainment and definitions.

SETTING

Cohort and surveillance studies that measured ZIKV infection during pregnancy or at birth and measured fetal, infant, or child outcomes were identified through a systematic search and consultations with ZIKV researchers and Ministries of Health from 20 countries or territories.

PARTICIPANTS

Fifty-four cohort or active surveillance studies shared deidentified data for the IPD-MA and completed the metadata survey, representing 33 061 women (11 020 with ZIKV) and 18 281 children.

PRIMARY AND SECONDARY OUTCOME MEASURES

Study-level heterogeneity in exposure, outcome and covariate ascertainment and definitions.

RESULTS

Median study sample size was 268 (IQR=100, 698). Inclusion criteria, follow-up procedures and exposure and outcome ascertainment were highly heterogenous, differing meaningfully across regions and multisite studies. Enrolment duration and follow-up for children after birth varied before and after the declaration of the Public Health Emergency of International Concern (PHEIC) and according to the type of funding received.

CONCLUSION

This work highlights the logistic and statistical challenges that must be addressed to account for the multiple sources of within-study and between-study heterogeneity when conducting IPD-MAs of data collected in the research response to emergent pathogens like ZIKV.

Decreased CSTB, RAGE, and Axl Receptor Are Associated with Zika Infection in the Human Placenta

Zika virus (ZIKV) compromises placental integrity, infecting the fetus. However, the mechanisms associated with ZIKV penetration into the placenta leading to fetal infection are unknown. Cystatin B (CSTB), the receptor for advanced glycation end products (RAGE), and tyrosine-protein kinase receptor UFO (AXL) have been implicated in ZIKV infection and inflammation. This work investigates CSTB, RAGE, and AXL receptor expression and activation pathways in ZIKV-infected placental tissues at term. The hypothesis is that there is overexpression of CSTB and increased inflammation affecting RAGE and AXL receptor expression in ZIKV-infected placentas. Pathological analyses of 22 placentas were performed to determine changes caused by ZIKV infection. Quantitative proteomics, immunofluorescence, and western blot were performed to analyze proteins and pathways affected by ZIKV infection in frozen placentas. The pathological analysis confirmed decreased size of capillaries, hyperplasia of Hofbauer cells, disruption in the trophoblast layer, cell agglutination, and ZIKV localization to the trophoblast layer. In addition, there was a significant decrease in CSTB, RAGE, and AXL expression and upregulation of caspase 1, tubulin beta, and heat shock protein 27. Modulation of these proteins and activation of inflammasome and pyroptosis pathways suggest targets for modulation of ZIKV infection in the placenta.

Association of congenital Zika syndrome with dental alterations in children with microcephaly

The effects of congenital Zika syndrome (CZS) on the tooth development of infected children are not well known. The aim of this study was to analyze the association of CZS with dental alterations in children with microcephaly seen at a referral hospital in Rio Grande do Norte, Brazil. The chronology and sequence of tooth eruption and the presence of dental alterations were evaluated by a single calibrated examiner (kappa > 0.80) in 62 children aged 7 to 35 months with microcephaly associated with CZS and other congenital infections. Medical data of the mother and child were collected from the records and the parents responded to a socioeconomic questionnaire. Descriptive analysis and Fisher's exact test were used (5% significance level). The mean age of the children was 26.4 months (SD = 7.52). The mean weight and head circumference at birth were 2,593 g (SD = 0.60) and 29.6 cm (SD = 2.48), respectively. Microcephaly was associated with congenital Zika virus infection in 79% of cases and with other congenital infections in 21%. No significant association was found between CZS and alterations in the chronology (p = 1.00) or sequence of tooth eruption (p = 0.16) or changes in enamel development (p = 1.00). In conclusion, children with microcephaly exhibit a delay and alterations in the sequence of tooth eruption of primary teeth, as well as developmental defects of enamel, which are not associated with Zika virus infection.

The global trends and regional differences in incidence of Zika virus infection and implications for Zika virus infection prevention

Background

Zika virus (ZIKV) infection has potential result in severe birth effects. An improved understanding of global trend and regional differences is needed.

Methods

Annual ZIKV infection episodes and incidence rates were collected from Global Burden of Disease Study 2019. Episodes changes and estimated annual percentage changes (EAPCs) of age-standardized incidence rate (ASR) were calculated. Top passenger airport-pairs were obtained from the International Air Transport Association to understand places susceptible to imported ZIKV cases.

Results

Globally, the ASR increased by an average of 72.85% (95%CI: 16.47% to 156.53%) per year from 2011 to 2015 and subsequently decreased from 20.25 per 100,000 in 2015 to 3.44 per 100,000 in 2019. Most of ZIKV infections clustered in Latin America. The proportion of episodes in Central and Tropical Latin America decreased in 2019 with sporadic episodes elsewhere. High Socio-Demographic Index (SDI) regions had more episodes in 2019 than in 2015. Additionally, 15–49 years group had the largest proportion of episodes, females had a higher number of episodes, and a higher incidence rate of 70 plus group was observed in males than females. Certain cities in Europe, North America and Latin America/Caribbean had a high population mobility in ZIKV outbreak areas considered a high risk of imported cases.

Conclusions

ZIKV infection is still a public health threat in Latin America and Caribbean and high SDI regions suffered an increasing trend of ZIKV infection. Interventions such as development of surveillance networks and vector-control should be attached to ZIKV control in these key regions. Reproductive suggestions should be taken to reduce ZIKV-related birth defects for the people of reproductive age who are facing a higher threat of ZIKV infection, especially females. Moreover, surveillance of travellers is needed to reverse the uptrends of travel-related imported ZIKV infection. More studies focusing on ZIKV should be performed to make targeted and effective prevention strategies in the future.

Zika virus (ZIKV) infection is a mosquito-borne illness and has potential result in severe birth effects. Currently, ZIKV is still causing an unprecedented ongoing epidemic in Latin America and threatening North America and potentially the rest of the world. This is the first study to assess the global landscape, long-term trends and regional differences in the incidence of ZIKV infection using the data from Global Burden of Disease (GBD) Study 2019, including the description of ZIKV infection episodes by different sex and by different year group, as well as the relationship between international travellers and imported ZIKV cases. Our study can not only serve as complement to previous studies, but also provide a more comprehensive perspective of global ZIKV infection prevention strategies.

Neurological Short-Term Outcomes of a Cohort of Children Born to Zika Virus-Infected Mothers in Barcelona

Zika virus (ZIKV) is a vector-borne flavivirus with a known teratogenic effect, yet the full spectrum has not been delineated. Studies on endemic areas tried to characterize the clinical outcomes of ZIKV intrauterine exposure. We aimed to describe early neurodevelopmental outcomes on prenatally ZIKV-exposed children in a non-endemic ZIKV area. This is a prospective observational cohort study conducted from May 2016 to December 2021 at Hospital Universitari Vall d’Hebron in Barcelona, Catalonia, Spain. We monitored for up to 24 months 152 children extracted from a pregnant women cohort with suspected ZIKV infection; eleven women (11/150; 7.3%) fulfilled the criteria for a confirmed ZIKV infection. Among the 152 children included, we describe two cases of congenital ZIKV syndrome (CZS) born from women with a confirmed ZIKV infection. Additionally, we describe five cases of other potentially ZIKV-related outcomes (OPZROs), all with normal birth cranial circumference and born to women with probable ZIKV infection. The low exposed prevalence of adverse outcomes in asymptomatic children at birth in a non-endemic area suggests that close follow-up should be addressed by primary care pediatricians instead of pediatric specialists. Further studies are needed to assess the effects of ZIKV intrauterine exposure beyond two years of life.

Surgical Correction of Neuromuscular Scoliosis Secondary to Congenital Zika Syndrome: A Case Report

CASE

Congenital Zika syndrome (CZS) has been noted after the South American pandemic of Zika virus which peaked in 2015 to 2016, and the associated sequelae are still being described. Scoliosis has been noted in patients with CZS; however, there is a paucity of literature on the prevalence or management of scoliosis secondary to this condition. We report the case of a 5-year-old girl with severe neuromuscular scoliosis due to CZS that was managed with halo-gravity traction, followed by a growth-friendly construct.

CONCLUSION

This case report highlights the need for more research focusing on the survivors of the Zika pandemic.

Prevalence of microcephaly and Zika virus infection in a pregnancy cohort in Kenya, 2017-2019

BACKGROUND

Zika virus (ZIKV), first discovered in Uganda in 1947, re-emerged globally in 2013 and was later associated with microcephaly and other birth defects. We determined the incidence of ZIKV infection and its association with adverse pregnancy and fetal outcomes in a pregnancy cohort in Kenya.

METHODS

From October 2017 to July 2019, we recruited and followed up women aged ≥ 15 years and ≤ 28 weeks pregnant in three hospitals in coastal Mombasa. Monthly follow-up included risk factor questions and a blood sample collected for ZIKV serology. We collected anthropometric measures (including head circumference), cord blood, venous blood from newborns, and any evidence of birth defects. Microcephaly was defined as a head circumference (HC) < 2 standard deviations (SD) for sex and gestational age. Severe microcephaly was defined as HC < 3 SD for sex and age. We tested sera for anti-ZIKV IgM antibodies using capture enzyme-linked immunosorbent assay (ELISA) and confirmed positives using the plaque reduction neutralization test (PRNT₉₀) for ZIKV and for dengue (DENV) on the samples that were ZIKV neutralizing antibody positive. We collected blood and urine from participants reporting fever or rash for ZIKV testing.

RESULTS

Of 2889 pregnant women screened for eligibility, 2312 (80%) were enrolled. Of 1916 recorded deliveries, 1816 (94.6%) were live births and 100 (5.2%) were either stillbirths or spontaneous abortions (< 22 weeks of gestation). Among 1236 newborns with complete anthropometric measures, 11 (0.9%) had microcephaly and 3 (0.2%) had severe microcephaly. A total of 166 (7.2%) participants were positive for anti-ZIKV IgM, 136 of whom became seropositive during follow-up. Among the 166 anti-ZIKV IgM positive, 3 and 18 participants were further seropositive for ZIKV and DENV neutralizing antibodies, respectively. Of these 3 and 18 pregnant women, one and 13 (72.2%) seroconverted with antibodies to ZIKV and DENV, respectively. All 308 samples (serum and urine samples collected during sick visits and samples that were anti-ZIKV IgM positive) tested by RT-PCR were negative for ZIKV. No adverse pregnancy or neonatal outcomes were reported among the three participants with confirmed ZIKV exposure. Among newborns from pregnant women with DENV exposure, four (22.2%) were small for gestational age and one (5.6%) had microcephaly.

CONCLUSIONS

The prevalence of severe microcephaly among newborns in coastal Kenya was high relative to published estimates from facility-based studies in Europe and Latin America, but little evidence of ZIKV transmission. There is a need for improved surveillance for microcephaly and other congenital malformations in Kenya.

Covid-19 vaccination in pregnancy

Pregnancy is an independent risk factor for severe covid-19. Vaccination is the best way to reduce the risk for SARS-CoV-2 infection and limit its morbidity and mortality. The current recommendations from the World Health Organization, Centers for Disease Control and Prevention, and professional organizations are for pregnant, postpartum, and lactating women to receive covid-19 vaccination. Pregnancy specific considerations involve potential effects of vaccination on fetal development, placental transfer of antibodies, and safety of maternal vaccination. Although pregnancy was an exclusion criterion in initial clinical trials of covid-19 vaccines, observational data have been rapidly accumulating and thus far confirm that the benefits of vaccination outweigh the potential risks. This review examines the evidence supporting the effectiveness, immunogenicity, placental transfer, side effects, and perinatal outcomes of maternal covid-19 vaccination. Additionally, it describes factors associated with vaccine hesitancy in pregnancy. Overall, studies monitoring people who have received covid-19 vaccines during pregnancy have not identified any pregnancy specific safety concerns. Additional information on non-mRNA vaccines, vaccination early in pregnancy, and longer term outcomes in infants are needed. To collect this information, vaccination during pregnancy must be prioritized in vaccine research.