Microcephaly in north-east Brazil: a retrospective study on neonates born between 2012 and 2015

The ZIKV NS5 Protein Aberrantly Alters the Tubulin Cytoskeleton, Induces the Accumulation of Autophagic p62 and Affects IFN Production: HDAC6 Has Emerged as an Anti-NS5/ZIKV Factor

Zika virus (ZIKV) infection and pathogenesis are linked to the disruption of neurogenesis, congenital Zika syndrome and microcephaly by affecting neural progenitor cells. Nonstructural protein 5 (NS5) is the largest product encoded by ZIKV-RNA and is important for replication and immune evasion. Here, we studied the potential effects of NS5 on microtubules (MTs) and autophagy flux, together with the interplay of NS5 with histone deacetylase 6 (HDAC6). Fluorescence microscopy, biochemical cell-fractionation combined with the use of HDAC6 mutants, chemical inhibitors and RNA interference indicated that NS5 accumulates in nuclear structures and strongly promotes the acetylation of MTs that aberrantly reorganize in nested structures. Similarly, NS5 accumulates the p62 protein, an autophagic-flux marker. Therefore, NS5 alters events that are under the control of the autophagic tubulin-deacetylase HDAC6. HDAC6 appears to degrade NS5 by autophagy in a deacetylase- and BUZ domain-dependent manner and to control the cytoplasmic expression of NS5. Moreover, NS5 inhibits RNA-mediated RIG-I interferon (IFN) production, resulting in greater activity when autophagy is inhibited (i.e., effect correlated with NS5 stability). Therefore, it is conceivable that NS5 contributes to cell toxicity and pathogenesis, evading the IFN-immune response by overcoming HDAC6 functions. HDAC6 has emerged as an anti-ZIKV factor by targeting NS5.

Applying the Concepts of Benefit and Harm in Malaysian Bioethical Discourse: Analysis of Malaysian Fatwa

Rapid developments in science and technology have resulted in novel discoveries, leading to new questions particularly related to human values and ethics. Every discovery and technology has positive and negative implications and affects human lives either directly or indirectly, involving all walks of life. Bioethical discourse in Malaysia must consider the multiracial and multireligious background of Malaysia and especially the Islamic view as the majority of Malaysians are Muslims and Islam is the religion of the federation. This article discusses several selected bioethical issues in Malaysia by studying the application of maṣlaḥah (the public good) and mafsadah (evil and harms) in Malaysian Islamic rulings (fatwas). This article uses the critical interpretation approach, as this is an ethical, interpretive, textual, and contextual analysis. In a situation when there is a conflict between maṣlaḥah and avoidance of mafsadah, it is preferred to attempt to address both needs. However, if maṣlaḥah and avoidance of mafsadah are mutually exclusive, the decision to choose must be made by weighing (tarjīḥ) and choosing the one which is superior. The maṣlaḥah and mafsadah concepts play vital and significant roles in bioethical discourse to realize human essential interests, namely faith, life, lineage, intellect, and property, thus achieving maqāṣid al-sharī'ah (the ultimate goal of sharia). This concept helps in guiding bioethical discussions, especially in determining the priority between achieving benefits and avoiding harms. The application of this concept will also assist Malaysian authorities in formulating appropriate rulings, especially bioethical issues related to Malaysian Muslims' lives.

A guide for the use of fNIRS in microcephaly associated to congenital Zika virus infection

Congenital Zika Syndrome (CZS) is characterized by changes in cranial morphology associated with heterogeneous neurological manifestations and cognitive and behavioral impairments. In this syndrome, longitudinal neuroimaging could help clinicians to predict developmental trajectories of children and tailor treatment plans accordingly. However, regularly acquiring magnetic resonance imaging (MRI) has several shortcomings besides cost, particularly those associated with childrens' clinical presentation as sensitivity to environmental stimuli. The indirect monitoring of local neural activity by non-invasive functional near-infrared spectroscopy (fNIRS) technique can be a useful alternative for longitudinally accessing the brain function in children with CZS. In order to provide a common framework for advancing longitudinal neuroimaging assessment, we propose a principled guideline for fNIRS acquisition and analyses in children with neurodevelopmental disorders. Based on our experience on collecting fNIRS data in children with CZS we emphasize the methodological challenges, such as clinical characteristics of the sample, desensitization, movement artifacts and environment control, as well as suggestions for tackling such challenges. Finally, metrics based on fNIRS can be associated with established clinical metrics, thereby opening possibilities for exploring this tool as a long-term predictor when assessing the effectiveness of treatments aimed at children with severe neurodevelopmental disorders.

[Evaluation of implementation of the response to the public health emergency of microcephaly in Pernambuco State, Brazil]

This study aimed to assess the degree of implementation of the response to the emergency of microcephaly associated with Zika virus in Pernambuco State, Brazil. This was a normative evaluative study conducted in the initial epicenter of the public health emergency of international concern, from October 2015 to July 2017. A logical model was produced for the intervention under analysis, with the components of Management, Surveillance, and Care in the dimensions of structure, process, and result, based on technical publications and institutional guidelines, in addition to a corresponding log frame of indicators for assessment. Data were collected through a questionnaire, direct observation, and consultation of official documents. The results showed partial implementation (74.9%) of the response to the microcephaly emergency by the Pernambuco State Health Department, with the process dimension reaching 75% of the expected level and the structure dimension, 74.5%. Surveillance was the only component that was assessed as implemented (81%), although with a shortage of regional and laboratory investments, while Management (74.2%) and Care (68.8%) were partially implemented, with insufficiencies in items related to human resources and physical structure, planning, and evaluation. In conclusion, the response to the public health emergency of international concern involving microcephaly associated with the Zika virus was assessed as partially implemented, with different levels between the intervention´s components, especially surveillance when compared to management and care. The shortcomings signal the need for investments to deal with future public health emergencies, with a view towards more timely and adequate interventions.

Zika Virus Pathogenesis: A Battle for Immune Evasion

Zika virus (ZIKV) infection and its associated congenital and other neurological disorders, particularly microcephaly and other fetal developmental abnormalities, constitute a World Health Organization (WHO) Zika Virus Research Agenda within the WHO’s R&D Blueprint for Action to Prevent Epidemics, and continue to be a Public Health Emergency of International Concern (PHEIC) today. ZIKV pathogenicity is initiated by viral infection and propagation across multiple placental and fetal tissue barriers, and is critically strengthened by subverting host immunity. ZIKV immune evasion involves viral non-structural proteins, genomic and non-coding RNA and microRNA (miRNA) to modulate interferon (IFN) signaling and production, interfering with intracellular signal pathways and autophagy, and promoting cellular environment changes together with secretion of cellular components to escape innate and adaptive immunity and further infect privileged immune organs/tissues such as the placenta and eyes. This review includes a description of recent advances in the understanding of the mechanisms underlying ZIKV immune modulation and evasion that strongly condition viral pathogenesis, which would certainly contribute to the development of anti-ZIKV strategies, drugs, and vaccines.

Recent progresses and remaining challenges for the detection of Zika virus

Zika virus (ZIKV) has emerged as a particularly notorious mosquito-borne flavivirus, which can lead to a devastating congenital syndrome in the fetuses of pregnant mothers (e.g., microcephaly, spasticity, craniofacial disproportion, miscarriage, and ocular abnormalities) and cause the autoimmune disorder Guillain-Barre' syndrome of adults. Due to its severity and rapid dispersal over several continents, ZIKV has been acknowledged to be a global health concern by the World Health Organization. Unfortunately, the ZIKV has recently resurged in India with the potential for devastating effects. Researchers from all around the world have worked tirelessly to develop effective detection strategies and vaccines for the prevention and control of ZIKV infection. In this review, we comprehensively summarize the most recent research into ZIKV, including the structural biology and evolution, historical overview, pathogenesis, symptoms, and transmission. We then focus on the detection strategies for ZIKV, including viral isolation, serological assays, molecular assays, sensing methods, reverse transcription loop mediated isothermal amplification, transcription-mediated amplification technology, reverse transcription strand invasion based amplification, bioplasmonic paper-based device, and reverse transcription isothermal recombinase polymerase amplification. To conclude, we examine the limitations of currently available strategies for the detection of ZIKV, and outline future opportunities and research challenges.

Genome editing in stem cells for genetic neurodisorders

The recent advent of genome editing techniques and their rapid improvement paved the way in establishing innovative human neurological disease models and in developing new therapeutic opportunities. Human pluripotent (both induced or naive) stem cells and neural stem cells represent versatile tools to be applied to multiple research needs and, together with genomic snip and fix tools, have recently made possible the creation of unique platforms to directly investigate several human neural affections. In this chapter, we will discuss genome engineering tools, and their recent improvements, applied to the stem cell field, focusing on how these two technologies may be pivotal instruments to deeply unravel molecular mechanisms underlying development and function, as well as disorders, of the human brain. We will review how these frontier technologies may be exploited to investigate or treat severe neurodevelopmental disorders, such as microcephaly, autism spectrum disorder, schizophrenia, as well as neurodegenerative conditions, including Parkinson's disease, Huntington's disease, Alzheimer's disease, and spinal muscular atrophy.

Microcephaly epidemic in Brazil: An earlier chapter

OBJECTIVE

Identify risk factors for microcephaly and evaluate historical trends of microcephaly and arboviruses to recognize patterns and anomalies that indicate the beginning of the microcephaly epidemic associated with Zika infection.

METHODS

The head circumferences of 62,298 newborns was analyzed to identify cases of microcephaly between 2014 and 2017. We compared the groups of newborns with normal head circumferences and those with microcephaly to identify risk factors. A time series with the incidences of microcephaly was analyzed to assess the appearance of anomalous values in order to identify the beginning of the microcephaly epidemic. Data on the incidence of dengue fever was used to develop a control chart, aiming to identify changes in incidence and seasonality that could suggest the circulation of a new arbovirus.

FINDINGS

Premature newborns, children of mothers under 20 years of age and those born in 2014 and 2015 had a higher risk of microcephaly. Three quarters with anomalous incidences of microcephaly were identified, the first in 2014 and the others in 2015. The dengue fever epidemic curve in 2013 shows persistence of high incidences in atypical periods, suggesting the entry of a new virus in the 3rd and 4th quarters.

CONCLUSIONS

These findings represent epidemiological evidence of the existence of cases of Zika virus between the 2nd quarter of 2013 and the beginning of 2014. The results add new elements to understanding the Zika virus epidemic in the Americas.

Risk of Zika microcephaly correlates with features of maternal antibodies

Zika virus (ZIKV) infection during pregnancy causes congenital abnormalities, including microcephaly. However, rates vary widely, and the contributing risk factors remain unclear. We examined the serum antibody response to ZIKV and other flaviviruses in Brazilian women giving birth during the 2015-2016 outbreak. Infected pregnancies with intermediate or higher ZIKV antibody enhancement titers were at increased risk to give birth to microcephalic infants compared with those with lower titers (P < 0.0001). Similarly, analysis of ZIKV-infected pregnant macaques revealed that fetal brain damage was more frequent in mothers with higher enhancement titers. Thus, features of the maternal antibodies are associated with and may contribute to the genesis of ZIKV-associated microcephaly.

Association of Malaria Infection During Pregnancy With Head Circumference of Newborns in the Brazilian Amazon

Importance

Malaria during pregnancy is associated with adverse events for the fetus and newborn, but the association of malaria during pregnancy with the head circumference of the newborn is unclear.

Objective

To investigate the association of malaria during pregnancy with fetal head growth.

Design, Setting, and Participants

Two cohort studies were conducted at the general maternity hospital of Cruzeiro do Sul (Acre, Brazil) in the Amazonian region. One cohort study prospectively enrolled noninfected and malaria-infected pregnant women who were followed up until delivery, between January 2013 and April 2015. The other cohort study was assembled retrospectively using clinical and malaria data from all deliveries that occurred between January 2012 and December 2013. Data analyses were conducted from January to August 2017 and revised in November 2018. Clinical data from pregnant women and anthropometric measures of their newborns were evaluated. A total of 600 pregnant women were enrolled through volunteer sampling (prospective cohort study), and 4697 pregnant women were selected by population-based sampling (retrospective cohort study). After application of exclusion criteria, data from 251 (prospective cohort study) and 232 (retrospective cohort study) malaria-infected and 158 (prospective cohort study) and 3650 (retrospective cohort study) noninfected women were evaluated.

Exposure

Malaria during pregnancy.

Main Outcomes and Measures

The primary end point was the incidence of altered head circumference in newborns delivered from malaria-infected mothers compared with that from noninfected mothers. Secondary end points included measures of placental pathology relative to newborn head circumference.

Results

In total, 4291 maternal-child pairs were analyzed. Among 409 newborns in the prospective cohort study, the mothers of 251 newborns had malaria during pregnancy, infected with Plasmodium vivax, Plasmodium falciparum, or both. Among 3882 newborns in the retrospective cohort study, 232 were born from mothers that had malaria during pregnancy. The prevalence of newborns with a small head (19 [30.7%] in the prospective cohort study and 30 [36.6%] in the retrospective cohort study) and the prevalence of microcephaly among newborns (5 [8.1%] in the prospective cohort study and 6 [7.3%] in the retrospective cohort study) were higher among newborns from women infected with P falciparum during pregnancy. Multivariate logistic regression analyses revealed that P falciparum infection during pregnancy represented a significant risk factor for the occurrence of small head circumference in newborns (prospective cohort study: odds ratio, 3.15; 95% CI, 1.52-6.53; P = .002; retrospective cohort study: odds ratio, 1.91; 95% CI, 1.21-3.04; P = .006). Placental pathologic findings corroborated this association, with more syncytial nuclear aggregates and inflammatory infiltrates occurring in placentas of newborns born with decreased head circumference.

Conclusions and Relevance

This study indicates that falciparum malaria during pregnancy is associated with decreased head circumference in newborns, which is in turn associated with evidence of placental malaria.

Knowledge and perceptions of Zika virus transmission in the community of Puerto Plata, Dominican Republic

Background

Zika virus is associated with increased cases of both microcephaly and Guillain-Barré syndrome. Community knowledge, perceptions and practices to prevent infection with the Zika virus are not well understood, particularly among high risk populations living in resource-poor and Zika-endemic areas. Our objective was to assess knowledge of symptoms, health effects and prevention practices associated with Zika virus in rural communities on the northern coast of the Dominican Republic.

Methods

Study participants were contacted while attending community events such as free medical clinics and invited to be interviewed regarding their knowledge, attitudes, and perceptions of Zika virus using the World Health Organization’s Zika survey tool.

Results

Of the 75 Dominicans that participated, 33% did not know who could become infected with Zika. In addition, only 40% of respondents were able to identify mosquitoes or sexual transmission as the primary routes of infection though 51% of respondents thought that Zika was an important issue in their community.

Conclusions

This study found that general knowledge regarding the basic risks and transmission of Zika were not well understood among a sample of rural Dominicans. Our findings highlight disparities in knowledge and perception of risk from Zika in rural areas compared to previous studies conducted in the Dominican Republic. Education about the basic risks and transmission of Zika are critically needed in these remote populations to reduce Zika transmission.

Systematic review of factors associated with the development of Guillain-Barré syndrome 2007-2017: what has changed?

OBJECTIVE

The objective of this study was to describe the factors associated with the development of Guillain-Barré syndrome, both infectious and non-infectious, during and after the A(H1N1) influenza pandemic in 2009 and the recent Zika virus epidemic in the Americas.

METHOD

Systematic review of literature on factors associated with the development of the Guillain-Barré syndrome published between 2007 and 2017 listed in EBSCO, MEDLINE and LILACS databases. The quality of the studies was evaluated using the Newcastle Ottawa Scale.

RESULTS

Thirty-four articles met inclusion criteria and were selected for analysis. Their quality was considered good in relation to most of the items evaluated. Many aetiological agents had the results of association with Guillain-Barré syndrome, among them Campylobacter jejuni, influenza vaccine - both pandemic and seasonal vaccines, respiratory infection, gastrointestinal infection among others. The aetiological agents found are, in most part, the same reported prior to the study period. The association with surgeries, chikungunya virus (CHIKV), Zika virus and quadrivalent human papillomavirus vaccine stand out as new aetiological agents in the list of the various possible agents that trigger Guillain-Barré syndrome reported in the study period. There were no Brazilian studies identified during this period.

CONCLUSIONS

The results of the review reaffirmed C. jejuni as the major trigger of GBS, whereas the association of influenza vaccines and GBS is less clear; Zika virus infection in association with GBS was found in only one study.

Improved Immune Responses Against Zika Virus After Sequential Dengue and Zika Virus Infection in Humans

The high levels of dengue-virus (DENV) seroprevalence in areas where the Zika virus (ZIKV) is circulating and the cross-reactivity between these two viruses have raised concerns on the risk of increased ZIKV disease severity for patients with a history of previous DENV infections. To determine the role of DENV preimmunity in ZIKV infection, we analyzed the T- and B-cell responses against ZIKV in donors with or without previous DENV infection. Using peripheral blood mononuclear cells (PBMCs) from donors living in an endemic area in Colombia, we have identified, by interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) assay, most of the immunodominant ZIKV T-cell epitopes in the nonstructural (NS) proteins NS1, NS3, and NS5. Analyses of the T- and B-cell responses in the same donors revealed a stronger T-cell response against peptides conserved between DENV and ZIKV, with a higher level of ZIKV-neutralizing antibodies in DENV-immune donors in comparison with DENV-naïve donors. Strikingly, the potential for antibody-mediated enhancement of ZIKV infection was reduced in donors with sequential DENV and ZIKV infection in comparison with donors with DENV infection only. Altogether, these data suggest that individuals with DENV immunity present improved immune responses against ZIKV.

Alterations in the primary teeth of children with microcephaly in Northeast Brazil: a comparative study

BACKGROUND

The outbreak of microcephaly between 2015 and 2017 in Brazil created an international public health emergency.

AIM

This study sought to evaluate the chronology, sequence of eruption, and the presence of anomalies amongst children with microcephaly compared with normoreactive children.

DESIGN

A comparative study of 108 children aged 0-2 years attending public services was conducted. The microcephaly group (MG; n = 54) and the nonmicrocephaly group (NMG; n = 54) were matched by age, gender, and family income at a 1 : 1 ratio. Erupted teeth and the presence of anomalies were evaluated and compared. Chi-square tests, Pearson's correlations, Fisher's exact tests, and Student's t-tests were applied (α = 0.05).

RESULTS

No between-group differences were found with regard to gender (P = 0.560) or age (P = 0.529). The MG presented with a higher percentage of alterations in eruption sequence, opacity, self-injury, and delayed eruption compared with the NMG (P < 0.05). The MG was more likely to exhibit changes in tooth eruption sequence (OR = 12.23, 95% CIs = 3.25-46.03, P < 0.001), delayed eruption (OR = 23.12; 95% CIs = 7.09-75.40, P < 0.001), and opacity (n = 12.19, 95% CIs = 1.44-103.28, P = 0.022) than the NMG.

CONCLUSION

Children with microcephaly present with greater delays in chronology, alterations in eruption sequence, and enamel defects than normoreactive children.

Ethics, health policy, and Zika: From emergency to global epidemic?

Zika virus was recognised in 2016 as an important vector-borne cause of congenital malformations and Guillain-Barré syndrome, during a major epidemic in Latin America, centred in Northeastern Brazil. The WHO and Pan American Health Organisation (PAHO), with partner agencies, initiated a coordinated global response including public health intervention and urgent scientific research, as well as ethical analysis as a vital element of policy design. In this paper, we summarise the major ethical issues raised during the Zika epidemic, highlighting the PAHO ethics guidance and the role of ethics in emergency responses, before turning to ethical issues that are yet to be resolved. Zika raises traditional bioethical issues related to reproduction, prenatal diagnosis of serious malformations and unjust disparities in health outcomes. But the epidemic has also highlighted important issues of growing interest in public health ethics, such as the international spread of infectious disease; the central importance of reproductive healthcare in preventing maternal and neonatal morbidity and mortality; diagnostic and reporting biases; vector control and the links between vectors, climate change, and disparities in the global burden of disease. Finally, there are controversies regarding Zika vaccine research and eventual deployment. Zika virus was a neglected disease for over 50 years before the outbreak in Brazil. As it continues to spread, public health agencies should promote gender equity and disease control efforts in Latin America, while preparing for the possibility of a global epidemic.

Clinical assessment and brain findings in a cohort of mothers, fetuses and infants infected with ZIKA virus

BACKGROUND

Congenital Zika virus (ZIKV) infection can be detected in both the presence and absence of microcephaly and manifests as a number of signs and symptoms that are detected clinically and by neuroimaging. However, to date, qualitative and quantitative measures for the purpose of diagnosis and prognosis are limited.

OBJECTIVES

Main objectives of this study conducted on fetuses and infants with confirmed congenital Zika virus infection and detected brain abnormalities were (1) to assess the prevalence of microcephaly and the frequency of the anomalies that include a detailed description based on ultrasound and magnetic resonance imaging in fetuses and ultrasound, magnetic resonance imaging, and computed tomography imaging postnatally, (2) to provide quantitative measures of fetal and infant brain findings by magnetic resonance imaging with the use of volumetric analyses and diffusion-weighted imaging, and (3) to obtain additional information from placental and fetal histopathologic assessments and postnatal clinical evaluations.

STUDY DESIGN

This is a longitudinal cohort study of Zika virus-infected pregnancies from a single institution in Colombia. Clinical and imaging findings of patients with laboratory-confirmed Zika virus infection and fetal brain anomalies were the focus of this study. Patients underwent monthly fetal ultrasound scans, neurosonography, and a fetal magnetic resonance imaging. Postnatally, infant brain assessment was offered by the use of ultrasound imaging, magnetic resonance imaging, and/or computed tomography. Fetal head circumference measurements were compared with different reference ranges with <2 or <3 standard deviations below the mean for the diagnosis of microcephaly. Fetal and infant magnetic resonance imaging images were processed to obtain a quantitative brain volumetric assessment. Diffusion weighted imaging sequences were processed to assess brain microstructure. Anthropometric, neurologic, auditory, and visual assessments were performed postnatally. Histopathologic assessment was included if patients opted for pregnancy termination.

RESULTS

All women (n=214) had been referred for Zika virus symptoms during pregnancy that affected themselves or their partners or if fetal anomalies that are compatible with congenital Zika virus syndrome were detected. A total of 12 pregnant patients with laboratory confirmation of Zika virus infection were diagnosed with fetal brain malformations. Most common findings that were assessed by prenatal and postnatal imaging were brain volume loss (92%), calcifications (92%), callosal anomalies (100%), cortical malformations (89%), and ventriculomegaly (92%). Results from fetal brain volumetric assessment by magnetic resonance imaging showed that 1 of the most common findings associated with microcephaly was reduced supratentorial brain parenchyma and increased subarachnoid cerebrospinal fluid. Diffusion weighted imaging analyses of apparent diffusion coefficient values showed microstructural changes. Microcephaly was present in 33.3-58.3% of the cases at referral and was present at delivery in 55.6-77.8% of cases. At birth, most of the affected neonates (55.6-77.8%) had head circumference measurements >3 standard deviations below the mean. Postnatal imaging studies confirmed brain malformations that were detected prenatally. Auditory screening results were normal in 2 cases that were assessed. Visual screening showed different anomalies in 2 of the 3 cases that were examined. Pathologic results that were obtained from 2 of the 3 cases who opted for termination showed similar signs of abnormalities in the central nervous system and placental analyses, including brain microcalcifications.

CONCLUSION

Congenital microcephaly is not an optimal screening method for congenital Zika virus syndrome, because it may not accompany other evident and preceding brain findings; microcephaly could be an endpoint of the disease that results from progressive changes that are related to brain volume loss. Long-term studies are needed to understand the clinical and developmental relevance of these findings.

Immune Responses to Dengue and Zika Viruses-Guidance for T Cell Vaccine Development

Despite numerous efforts to identify the molecular and cellular effectors of the adaptive immunity that induce a long-lasting immunity against dengue or Zika virus infection, the specific mechanisms underlying such protective immunity remain largely unknown. One of the major challenges lies in the high level of dengue virus (DENV) seroprevalence in areas where Zika virus (ZIKV) is circulating. In the context of such a pre-existing DENV immunity that can exacerbate ZIKV infection and disease, and given the lack of appropriate treatment for ZIKV infection, there is an urgent need to develop an efficient vaccine against DENV and ZIKV. Notably, whereas several ZIKV vaccine candidates are currently in clinical trials, all these vaccine candidates have been designed to induce neutralizing antibodies as the primary mechanism of immune protection. Given the difficulty to elicit simultaneously high levels of neutralizing antibodies against the different DENV serotypes, and the potential impact of pre-existing subneutralizing antibodies induced upon DENV infection or vaccination on ZIKV infection and disease, additional or alternative strategies to enhance vaccine efficacy, through T cell immunity, are now being considered. In this review, we summarize recent discoveries about cross-reactive B and T cell responses against DENV and ZIKV and propose guidelines for the development of safe and efficient T cell vaccines targeting both viruses.

A novel proximal 3q29 chromosome microdeletion in a Chinese patient with Chiari malformation type II and Sprengel's deformity

Background

Chiari malformation type II (CM-II) is mainly characterized by elongation and descent of the cerebellum through the foramen magnum into the spinal canal. Moreover, CM-II is uniquely associated with myelomeningocele. Sprengel’s deformity refers to the malposition of the scapula, i.e. scapular elevation which is sometimes accompanied with scapula dysplasia. Although few familial cases of CM-II and Sprengel’s deformity have been previously reported, both of these defects are considered to be sporadic, thus the exact etiology and causative genes have largely remained unknown.

Case presentation

The patient was diagnosed with CM-II accompanied with Sprengel’s deformity. Further genetic investigation revealed a novel 666 kb microdeletion located in 3q29 (chr3:194,532,035–195,198,585; Hg19). Subsequently, genes within the affected region were summarized, and XXYLT1 and ACAP2 were identified as the candidate genes.

Conclusion

We reported a case of a patient with CM-II and Sprengel’s deformity harboring a microdeletion in 3q29. This case highlights the importance of 3q29 in early neural and skeletal development, as well as expands the phenotype spectrum of this rare disorder.

High Background Congenital Microcephaly in Rural Guatemala: Implications for Neonatal Congenital Zika Virus Infection Screening

A variety of microcephaly case definitions detect high background prevalence in rural Guatemala, which complicates congenital Zika screening efforts. In addition, gestational age is needed for most screening tools but is usually unknown in low-resource settings. Fenton growth curves, originally designed for use in preterm infants, offer a standardized approach to adjust for unknown gestational age and may improve screening efforts.

Background:

Congenital microcephaly is the result of a disturbance in early brain development and can have multiple etiologies. Establishing background prevalence of microcephaly in Zika virus (ZIKV)-affected areas is important for improving identification of ZIKV-affected newborns. However, to date, there is limited consistent guidance for the accurate identification of microcephaly in infants of unknown gestational age, a common concern in low- and middle-income countries.

Methods:

Occipital frontal head circumference (OFC) obtained from infants (0–13 days) of unknown gestational age at enrollment in a pregnancy registry in rural Guatemala from August 2014 to March 2016 were retrospectively reviewed. Trained community health nurses recorded anthropometry in an online database. In April 2015, ZIKV was identified in this population. Gestational age was approximated in 2 ways: presumed term and estimated using z-score of zero for height on modified Fenton growth curves. After which, z-scores for OFC and weight were obtained. Microcephaly and microcephaly background prevalence were estimated using 7 established microcephaly case definitions from national and international organizations and 3 proposed definitions using Fenton growth curves. Independent associations with microcephaly and OFC, including relationship with date of birth, were assessed with prevalence ratios and linear regression.

Results:

For 296 infants, the mean OFC was 33.1 cm (range, 29.5 to 37 cm) and the mean OFC z-score was −0.68. Depending on case definition, 13 to 125 infants were classified as having microcephaly (background prevalence 439 to 4,223 per 10,000 live births), and 1 to 9 infants were classified as having severe microcephaly (<−3 standard deviation [SD]) (34 to 304 per 10,000 live births). Five (1.7%) infants met all the microcephaly case definitions. Weight ≤−1 SD (prevalence rate [PR], 3.77; 95% confidence interval [CI]: 1.6 to 8.8; P=.002) and small for gestational age (PR, 4.68; 95% CI, 1.8 to 12.3; P=.002) were associated with microcephaly. Date of birth was not associated with OFC z-score or OFC after adjusting for gestational age and gender.

Conclusions:

Estimated background microcephaly is high in rural Guatemala compared with reported rates in Latin America prior to ZIKV epidemic, which has important implications for neonatal screening programs for congenital ZIKV infection. Fenton growth curves offer a standardized approach to the identification of microcephaly in infants of unknown gestational age.

Maternal Zika virus infection and newborn microcephaly-an analysis of the epidemiological evidence

PURPOSE

To evaluate whether existing data and evidence support a causal link between maternal Zika virus (ZIKV) infection and newborn microcephaly.

METHODS

I quantified and compared the prevalence of all and severe microcephaly in Brazil, during and before 2015-2016, to assess whether an outbreak has occurred, used time series analysis to evaluate if the presumed outbreak was linked to a previous outbreak of ZIKV infections, and quantitatively synthesized published data from observational studies testing this association.

RESULTS

The prevalences of microcephaly in 2015-2016 were similar or lower than background levels (prevalence ratio [PR] for all microcephaly: 0.19; 95% confidence intervals [CI]: 0.17, 0.20). Changes in the number of cases of ZIKV infections at times matching 11-18 weeks of pregnancy were not followed by changes in the number of microcephaly cases (PR for infection at 12 weeks: 1.02; 95% CI: 0.99, 1.05). In observational studies, the prevalence of microcephaly was not significantly increased in newborns of Zika-infected mothers (average PR: 1.30; 95% CI: 0.84, 2.02).

CONCLUSIONS

Existing evidence is insufficient to claim maternal ZIKV infection causes microcephaly. Although a public health response seems sensible, it should be consistent with existing knowledge and consider risks, potential benefits and harm, and competing priorities.

Epidemiological and ecological determinants of Zika virus transmission in an urban setting

The Zika virus has emerged as a global public health concern. Its rapid geographic expansion is attributed to the success of Aedes mosquito vectors, but local epidemiological drivers are still poorly understood. Feira de Santana played a pivotal role in the Chikungunya epidemic in Brazil and was one of the first urban centres to report Zika infections. Using a climate-driven transmission model and notified Zika case data, we show that a low observation rate and high vectorial capacity translated into a significant attack rate during the 2015 outbreak, with a subsequent decline in 2016 and fade-out in 2017 due to herd-immunity. We find a potential Zika-related, low risk for microcephaly per pregnancy, but with significant public health impact given high attack rates. The balance between the loss of herd-immunity and viral re-importation will dictate future transmission potential of Zika in this urban setting.

Mosquitoes can transmit viruses that cause Zika, dengue and several other tropical diseases that affect humans. Zika virus usually causes mild symptoms, but it is thought that infection during pregnancy can lead to brain abnormalities, including microcephaly, where babies are born with an abnormally small head. Recent studies have shed light on how the Zika virus spread from Africa to reach South America, the Caribbean and North America. However, much less is known about the ecological factors that contribute to the spread of the virus within towns, cities and other local areas.

In 2015, Brazil was struck by an outbreak of the Zika virus that led to an international public health emergency. Lourenço et al. used a mathematical model to explore the local conditions within Feira de Santana (a major urban center in Brazil) that contributed to the outbreak. The model took into account numerous factors, including temperature, humidity, rainfall and the mosquito life-cycle, which made it possible to reconstruct the history of the virus over the past three years and to make projections for the next decades.

It revealed that most of the infections occured during 2015, with approximately 65% of the population infected. The incidences of new infections declined in 2016, as increasing numbers of local people had already been exposed to the virus and became immune. Temperature and humidity appeared to have played a critical role in sustaining the mosquito population carrying the Zika virus.

Further analysis suggests that the risk of Zika virus causing microcephaly is very low – only 0.3–0.5% of the pregnant women in Feira de Santana who were infected with Zika gave birth to a baby with the condition. What therefore makes Zika a public health concern is the combination of a low risk with very high infection rates, which can affect a large number of pregnancies.

This study will help researchers and policy makers to predict how the Zika virus will behave in the coming years. It also highlights the limitations and successes of the current system of surveillance. Moreover, it will help to identify critical time periods in the year when mosquito control strategies should be implemented to limit the spread of this virus. In future, this could help shape new local strategies to control Zika virus, dengue and other diseases carried by mosquitoes.

Prevalence of microcephaly in eight south-eastern and midwestern Brazilian neonatal intensive care units: 2011-2015

OBJECTIVE

To describe the prevalence of microcephaly in infants admitted to the neonatal intensive care units (NICUs) in eight private hospitals in south-eastern and midwestern Brazil, from 2011 to 2015.

DESIGN

Observational, cross-sectional study in a cohort of neonates.

SETTING

Eight private NICUs situated in the cities of Rio de Janeiro (RJ), São Paulo (SP) and Federal District of Brasilia (FDB).

PATIENTS

Neonates up to 7 days of age and >23 weeks of gestational age.

MAIN OUTCOME MEASURES

Primary outcomes were the annual prevalence of microcephaly and severe microcephaly, both overall and in subgroups according to gestational age, type of microcephaly (proportional or disproportional) and the NICU's location in RJ, SP or FDB.

RESULTS

In this cohort of 8275 neonates admitted to eight private NICUs, the overall prevalence of microcephaly was 5.6% (95% CI 5.1% to 6.1%) and severe microcephaly, 1.5% (95% CI 1.2% to 1.7%). There was no annual variation in these overall estimates (p=0.48 and p=0.99, respectively), nor in the studied subgroups. Microcephaly prevalence was higher in extremely premature and term newborns (7.7% and 7.2%; p<0.001, respectively). Disproportional microcephaly was much more common than proportional microcephaly (prevalence 5.0% vs 0.6%; p<0.001).

CONCLUSIONS

The prevalence of microcephaly showed little variation from 2011 to 2015 in these south-eastern and midwestern Brazilian NICUs, suggesting that the impact of the Zika epidemic in neonates that occurred mainly in the north-eastern region in 2015 did not yet affect the infants of those regions during the studied period. These prevalence results can serve as a reference for comparisons with any future Zika outbreaks in the same or similar populations from these regions.

Zika Virus Infection

In less than 2 years since entry into the Americas, we have witnessed the emergent spread of Zika virus into large subsets of immunologically naïve human populations and then encountered the devastating effects of microcephaly and brain anomalies that can arise from in utero infection with the virus. Diagnostic evaluation and management of affected infants continues to evolve as our understanding of Zika virus rapidly advances. The development of a safe and effective vaccine holds the potential to attenuate the spread of infection and limit the impact of congenital infection.

Microcephaly

Microcephaly is defined as a head circumference more than two standard deviations below the mean for gender and age. Congenital microcephaly is present at birth, whereas postnatal microcephaly occurs later in life. Genetic abnormalities, syndromes, metabolic disorders, teratogens, infections, prenatal, perinatal, and postnatal injuries can cause both congenital and postnatal microcephaly. Evaluation of patients with microcephaly begins with a thorough history and physical examination. In cases of worsening microcephaly or neurological signs or symptoms, neuroimaging, metabolic, or genetic testing should be strongly considered. Any further studies and workup should be directed by the presence of signs or symptoms pointing to an underlying diagnosis and are usually used as confirmatory testing for certain conditions. Neuroimaging with magnetic resonance imaging (MRI) is often the first diagnostic test in evaluating children with microcephaly. Genetic testing is becoming more common and is often the next step following neuroimaging when there is no specific evidence in the history or physical examination suggesting a diagnosis. Microcephaly is a lifelong condition with no known cure. The prognosis is usually worse for children who experienced an intrauterine infection or have a chromosomal or metabolic abnormality. Zika virus has rapidly spread since 2015, and maternal infection with this virus is associated with microcephaly and other serious brain abnormalities. Microcephaly has become much more prevalent in the news and scientific community with the recent emergence of Zika virus as a cause of congenital microcephaly.

Potential High-Risk Areas for Zika Virus Transmission in the Contiguous United States

OBJECTIVES

To understand where transmission of Zika virus has the highest likelihood to occur in the contiguous United States with regard to its transmission both sexually and via Aedes aegypti mosquito bites.

METHODS

We evaluated the 2 routes of transmission risk with predictors of sexually transmitted infections (percentage women of childbearing age, birthrate, gonorrhea and chlamydia rates, concentrated disadvantage) as a surrogate for unprotected sexual activity and the demographic distribution of the A. aegypti mosquito across 3108 counties in the contiguous United States.

RESULTS

We found that 507 counties had the highest risk of virus exposure via mosquito vector or unprotected sexual activity; these were concentrated in southern states extending northward along the Atlantic coast and southern California, with the highest predicted risk in Mississippi counties.

CONCLUSIONS

Identifying areas with higher transmission risk can inform prevention strategies and vector control, and assist in planning for diagnosis and treatment.

Check before you travel: Zika virus--another emerging global health threat

We now know that mosquitoes can transmit arboviruses such as the Zika virus (ZIKV) which is pandemic in Latin America. In order to avoid infection it is advised to avoid mosquitoes, but ZIKV can also be transmitted through blood donation, perinatally and sexually and has been detected in urine and saliva. Prevention against mosquito bites (particularly daytime bites) is best offered by avoiding mosquitoes and bites. To prevent the risk of transmission of ZIKV, standard infection control of all recent travellers to Zika affected areas should be conducted during dental care. This article will discuss how healthcare workers could contract diseases especially whilst working in the tropics or subtropics due to disease vectors such as mosquitoes and suggests prevention measures for this group.

Zika Virus: New Clinical Syndromes and Its Emergence in the Western Hemisphere

Zika virus (ZIKV) had remained a relatively obscure flavivirus until a recent series of outbreaks accompanied by unexpectedly severe clinical complications brought this virus into the spotlight as causing an infection of global public health concern. In this review, we discuss the history and epidemiology of ZIKV infection, recent outbreaks in Oceania and the emergence of ZIKV in the Western Hemisphere, newly ascribed complications of ZIKV infection, including Guillain-Barré syndrome and microcephaly, potential interactions between ZIKV and dengue virus, and the prospects for the development of antiviral agents and vaccines.

Zika Virus: Implications for Public Health

The World Health Organization has declared the current Zika virus (ZIKV) epidemic a public health emergency of international concern. Lack of vaccines and reliable diagnostic tests, broad geographical distribution of mosquito species that can transmit the virus, and absence of population immunity in newly affected countries are causes for concern. Although most infected persons are asymptomatic, ZIKV has been associated with a rise in cases of neurological complications and fetal central nervous system malformations. This defines such an arbovirus as something whose transmission should be prevented. This review summarizes the current understanding of ZIKV biology and epidemiology, as well as possible interventions to prevent contagion and transmission.