Ophthalmologic Manifestations Associated With Zika Virus Infection

Ocular Manifestations of Flavivirus Infections

Flaviviruses are a group of positive-sense, single-stranded RNA viruses predominantly transmitted by arthropods (mainly mosquitoes) that cause severe endemic infections and epidemics on a global scale. They represent a major cause of systemic morbidity and death and are expanding worldwide. Among this group, dengue fever, the West Nile virus, yellow fever, Japanese Encephalitis, and, recently, the Zika virus have been linked to a spectrum of ocular manifestations. These manifestations encompass subconjunctival hemorrhages and conjunctivitis, anterior and posterior uveitis (inclusive of vitritis, chorioretinitis, and retinal vasculitis), maculopathy, retinal hemorrhages, and optic neuritis. Clinical diagnosis of these infectious diseases is primarily based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. Diagnosis confirmation relies on laboratory testing, including RT-PCR and serological testing. Ocular involvement typically follows a self-limited course but can result in irreversible visual impairment. Effective treatments of flavivirus infections are currently unavailable. Prevention remains the mainstay for arthropod vector and zoonotic disease control. Effective vaccines are available only for the yellow fever virus, dengue virus, and Japanese Encephalitis virus. This review comprehensively summarizes the current knowledge regarding the ophthalmic manifestations of the foremost flavivirus-associated human diseases.

A Birth Cohort Follow-Up Study on Congenital Zika Virus Infection in Vietnam

We assessed the development, sensory status, and brain structure of children with congenital Zika virus (ZIKV) infection (CZI) at two years and preschool age. CZI was defined as either ZIKV RNA detection or positive ZIKV IgM and neutralization test in the cord or neonatal blood. Twelve children with CZI born in 2017-2018 in Vietnam, including one with Down syndrome, were assessed at 23-25.5 months of age, using Ages and Stages Questionnaire (ASQ-3), ASQ:Social-Emotional (ASQ:SE-2), Modified Checklist for Autism in Toddlers, automated auditory brainstem response (AABR), and Spot Vision Screener (SVS). They underwent brain CT and MRI. They had detailed ophthalmological examinations, ASQ-3, and ASQ:SE-2 at 51-62 months of age. None had birthweight or head circumference z-score < -3 except for the one with Down syndrome. All tests passed AABR (n = 10). No ophthalmological problems were detected by SVS (n = 10) and detailed examinations (n = 6), except for a girl's astigmatism. Communication and problem-solving domains in a boy at 24 months, gross-motor area in a boy, and gross-motor and fine-motor areas in another boy at 59-61 months were in the referral zone. Brain CT (n = 8) and MRI (n = 6) revealed no abnormalities in the cerebrum, cerebellum, or brainstem other than cerebellar hypoplasia with Down syndrome. The CZI children were almost age-appropriately developed with no brain or eye abnormalities. Careful and longer follow-up is necessary for children with CZI.

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.

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.

Differential Susceptibility of Fetal Retinal Pigment Epithelial Cells, hiPSC- Retinal Stem Cells, and Retinal Organoids to Zika Virus Infection

Zika virus (ZIKV) causes microcephaly and congenital eye disease. The cellular and molecular basis of congenital ZIKV infection are not well understood. Here, we utilized a biologically relevant cell-based system of human fetal retinal pigment epithelial cells (FRPEs), hiPSC-derived retinal stem cells (iRSCs), and retinal organoids to investigate ZIKV-mediated ocular cell injury processes. Our data show that FRPEs were highly susceptible to ZIKV infection exhibiting increased apoptosis, whereas iRSCs showed reduced susceptibility. Detailed transcriptomics and proteomics analyses of infected FRPEs were performed. Nucleoside analogue drug treatment inhibited ZIKV replication. Retinal organoids were susceptible to ZIKV infection. The Asian genotype ZIKV exhibited higher infectivity, induced profound inflammatory response, and dysregulated transcription factors involved in retinal organoid differentiation. Collectively, our study shows that ZIKV affects ocular cells at different developmental stages resulting in cellular injury and death, further providing molecular insight into the pathogenesis of congenital eye disease.

Nuclear accumulation of host transcripts during Zika Virus Infection

Zika virus (ZIKV) infects fetal neural progenitor cells (NPCs) causing severe neurodevelopmental disorders in utero. Multiple pathways involved in normal brain development are dysfunctional in infected NPCs but how ZIKV centrally reprograms these pathways remains unknown. Here we show that ZIKV infection disrupts subcellular partitioning of host transcripts critical for neurodevelopment in NPCs and functionally link this process to the up-frameshift protein 1 (UPF1). UPF1 is an RNA-binding protein known to regulate decay of cellular and viral RNAs and is less expressed in ZIKV-infected cells. Using infrared crosslinking immunoprecipitation and RNA sequencing (irCLIP-Seq), we show that a subset of mRNAs loses UPF1 binding in ZIKV-infected NPCs, consistent with UPF1's diminished expression. UPF1 target transcripts, however, are not altered in abundance but in subcellular localization, with mRNAs accumulating in the nucleus of infected or UPF1 knockdown cells. This leads to diminished protein expression of FREM2, a protein required for maintenance of NPC identity. Our results newly link UPF1 to the regulation of mRNA transport in NPCs, a process perturbed during ZIKV infection.

Evaluation of Anomalies and Neurodevelopment in Children Exposed to ZIKV during Pregnancy

Zika virus (ZIKV) infection in pregnancy is associated with birth and developmental alterations in infants. In this study, clinical records of 47 infants whose mothers had Zika during pregnancy or clinical manifestations compatible with Zika were reviewed. A description of the infants’ anomalies was established, and a neurodevelopmental assessment was performed on 18 infants, using the Evaluation of Infant Development (EDI for its initialism in Spanish) and DDST-II (Denver Developmental Screening Test II) tests. From his sample, 74.5% of the infants evaluated had major anomalies and 51.9% had minor anomalies. The incidence of major anomalies, related to trimester of pregnancy, was 84.2% for the first trimester, 77.8% for the second trimester, and 37.5% in the third trimester. A similar trend was observed in the frequency of infants without anomalies and was less evident in the incidence of minor anomalies (p = 0.016). Through neurodevelopmental assessments, EDI identified 27.8% of infants as having normal development, while 55.5% of affected infants had developmental delay, and 16.7% were at risk for developmental delay. The DDSST-II showed that 77.7% infants had delay in the gross motor and language area, 88.8% in the fine-adaptative motor area, and 72.2% in the personal–social area. In this work, children of mothers with ZIKV infection during pregnancy may have major or minor anomalies regardless of the trimester of pregnancy in which the infection occurred. The neurodevelopmental assessment shows that ZIKV can cause a developmental delay in infants with the fine-adaptative motor area being the most affected.

Zika Virus (ZIKV): A New Perspective on the Nanomechanical and Structural Properties

Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) from Flavivirus. In 2015, Brazil and other Latin American countries experienced an outbreak of ZIKV infections associated with severe neurological disorders such as Guillain–Barre syndrome (GBS), encephalopathy, and encephalitis. Here, a complete mechanical and structural analysis of the ZIKV has been performed using Atomic Force Microscopy (AFM). AFM analysis corroborated the virus mean size (~50 nm) and icosahedral geometry and revealed high mechanical resistance of both: the viral surface particle (~200 kPa) and its internal content (~800 kPa). The analysis demonstrated the detailed organization of the nucleocapsid structure (such as RNA strips). An interesting finding was the discovery that ZIKV has no surface self-assembling property. These results can contribute to the development of future treatment candidates and circumscribe the magnitude of viral transmission.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Pathogenesis and Manifestations of Zika Virus-Associated Ocular Diseases

Zika virus (ZIKV) is mosquito-borne flavivirus that caused a significant public health concern in French Polynesia and South America. The two major complications that gained the most media attention during the ZIKV outbreak were Guillain-Barré syndrome (GBS) and microcephaly in newborn infants. The two modes of ZIKV transmission are the vector-borne and non-vector borne modes of transmission. Aedes aegypti and Aedes albopictus are the most important vectors of ZIKV. ZIKV binds to surface receptors on permissive cells that support infection and replication, such as neural progenitor cells, dendritic cells, dermal fibroblasts, retinal pigment epithelial cells, endothelial cells, macrophages, epidermal keratinocytes, and trophoblasts to cause infection. The innate immune response to ZIKV infection is mediated by interferons and natural killer cells, whereas the adaptive immune response is mediated by CD8⁺T cells, Th1 cells, and neutralizing antibodies. The non-structural proteins of ZIKV, such as non-structural protein 5, are involved in the evasion of the host's immune defense mechanisms. Ocular manifestations of ZIKV arise from the virus' ability to cross both the blood-brain barrier and blood-retinal barrier, as well as the blood-aqueous barrier. Most notably, this results in the development of GBS, a rare neurological complication in acute ZIKV infection. This can yield ocular symptoms and signs. Additionally, infants to whom ZIKV is transmitted congenitally develop congenital Zika syndrome (CZS). The ocular manifestations are widely variable, and include nonpurulent conjunctivitis, anterior uveitis, keratitis, trabeculitis, congenital glaucoma, microphthalmia, hypoplastic optic disc, and optic nerve pallor. There are currently no FDA approved therapeutic agents for treating ZIKV infections and, as such, a meticulous ocular examination is an important aspect of the diagnosis. This review utilized several published articles regarding the ocular findings of ZIKV, antiviral immune responses to ZIKV infection, and the pathogenesis of ocular manifestations in individuals with ZIKV infection. This review summarizes the current knowledge on the viral immunology of ZIKV, interactions between ZIKV and the host's immune defense mechanism, pathological mechanisms, as well as anterior and posterior segment findings associated with ZIKV infection.

Neurodevelopment in normocephalic children with and without prenatal Zika virus exposure

OBJECTIVE

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

DESIGN

Cohort study.

SETTING

Public health centres in Grenada, West Indies.

PATIENTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Chalcones from Angelica keiskei (ashitaba) inhibit key Zika virus replication proteins

Zika virus (ZIKV) is a dangerous human pathogen and no antiviral drugs have been approved to date. The chalcones are a group of small molecules that are found in a number of different plants, including Angelica keiskei Koidzumi, also known as ashitaba. To examine chalcone anti-ZIKV activity, three chalcones, 4-hydroxyderricin (4HD), xanthoangelol (XA), and xanthoangelol-E (XA-E), were purified from a methanol-ethyl acetate extract from A. keiskei. Molecular and ensemble docking predicted that these chalcones would establish multiple interactions with residues in the catalytic and allosteric sites of ZIKV NS2B-NS3 protease, and in the allosteric site of the NS5 RNA-dependent RNA-polymerase (RdRp). Machine learning models also predicted 4HD, XA and XA-E as potential anti-ZIKV inhibitors. Enzymatic and kinetic assays confirmed chalcone inhibition of the ZIKV NS2B-NS3 protease allosteric site with IC₅₀s from 18 to 50 µM. Activity assays also revealed that XA, but not 4HD or XA-E, inhibited the allosteric site of the RdRp, with an IC₅₀ of 6.9 µM. Finally, we tested these chalcones for their anti-viral activity in vitro with Vero cells. 4HD and XA-E displayed anti-ZIKV activity with EC₅₀ values of 6.6 and 22.0 µM, respectively, while XA displayed relatively weak anti-ZIKV activity with whole cells. With their simple structures and relative ease of modification, the chalcones represent attractive candidates for hit-to-lead optimization in the search of new anti-ZIKV therapeutics.

Audiological follow-up of children with congenital Zika syndrome

How does the auditory function of children with congenital Zika syndrome present during the first three years of life? To determine the auditory function of children with congenital Zika syndrome during the first three years of life and estimate the frequency and long-term presentation of hearing loss in this syndrome, an auditory assessment with screening and diagnostic tests was conducted. The screening test consisted of measuring the short latency ABR using click stimuli. If the ABR click indicated hearing loss, confirmation was obtained with a frequency-specific ABR (FS-ABR), in which the stimuli were tone bursts at frequencies of 500 and 2000 Hz by bone and air conduction. This case series included 107 children with confirmed congenital Zika syndrome, and the cumulative incidence of sensorineural hearing loss in the first three years of life was 9.3% (10/107). There were no cases of delayed-onset or progressive deficits in hearing. Early presentation of sensorineural hearing loss seems to occur with a higher frequency in children with congenital Zika syndrome than in the general population. Sensorineural hearing loss resulting from congenital Zika virus infection does not appear to present with delayed onset or with progressive deficits.

Arbovirus, herpesvirus, and enterovirus associated with neurological syndromes in adult patients of a university hospital, 2017-2018

INTRODUCTION:

Herpesviruses, enteroviruses, and arboviruses are important because of their clinical relevance and ability to cause meningitis, encephalitis, meningoencephalitis, and other diseases. The clinical virology associated with diagnostic technologies can reduce the morbidity and mortality of such neurological manifestations. Here we aimed to identify the genomes of agents that cause neurological syndromes in cerebrospinal fluid (CSF) samples from patients with suspected nervous system infections admitted to the University Hospital of the University of Campinas, São Paulo, Brazil, in 2017-2018.

METHODS:

CSF samples collected from adult patients with neurological syndrome symptoms and negative CSF culture results were analyzed using polymerase chain reaction (PCR), reverse transcriptase-PCR, and real-time PCR, and their results were compared with their clinical symptoms. One CSF sample was obtained from each patient.

RESULTS:

Viral genomes were detected in 148/420 (35.2%) CSF samples: one of 148 (0.2%) was positive for herpes simplex virus-1; two (0.5%) for herpes simplex virus-2; eight (1.9%) for varicella-zoster virus; four (1%) for Epstein-Barr virus; one (0.2%) for cytomegalovirus; 32 (7.6%) for human herpesvirus-6; 30 (7.1%) for non-polio enterovirus; 67 (16.0%) for dengue virus, three (0.7%) for yellow fever virus, and 21 (5%) for Zika virus.

CONCLUSIONS:

The viral genomes were found in 35.2% of all analyzed samples, showing the high prevalence of viruses in the nervous system and the importance of using a nucleic acid amplification test to detect viral agents in CSF samples.

Modulating Neurological Complications of Emerging Infectious Diseases: Mechanistic Approaches to Candidate Phytochemicals

Growing studies are revealing the critical manifestations of influenza, dengue virus (DENV) infection, Zika virus (ZIKV) disease, and Ebola virus disease (EVD) as emerging infectious diseases. However, their corresponding mechanisms of major complications headed for neuronal dysfunction are not entirely understood. From the mechanistic point of view, inflammatory/oxidative mediators are activated during emerging infectious diseases towards less cell migration, neurogenesis impairment, and neuronal death. Accordingly, the virus life cycle and associated enzymes, as well as host receptors, cytokine storm, and multiple signaling mediators, are the leading players of emerging infectious diseases. Consequently, chemokines, interleukins, interferons, carbohydrate molecules, toll-like receptors (TLRs), and tyrosine kinases are leading orchestrates of peripheral and central complications which are in near interconnections. Some of the resulting neuronal manifestations have attracted much attention, including inflammatory polyneuropathy, encephalopathy, meningitis, myelitis, stroke, Guillain-Barré syndrome (GBS), radiculomyelitis, meningoencephalitis, memory loss, headaches, cranial nerve abnormalities, tremor, and seizure. The complex pathophysiological mechanism behind the aforementioned complications urges the need for finding multi-target agents with higher efficacy and lower side effects. In recent decades, the natural kingdom has been highlighted as promising neuroprotective natural products in modulating several dysregulated signaling pathways/mediators. The present study provides neuronal manifestations of some emerging infectious diseases and underlying pathophysiological mechanisms. Besides, a mechanistic-based strategy is developed to introduce candidate natural products as promising multi-target agents in combating major dysregulated pathways towards neuroprotection in influenza, DENV infection, ZIKV disease, and EVD.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Minireview: Epidemiological impact of arboviral diseases in Latin American countries, arbovirus-vector interactions and control strategies

Mosquitoes are the most crucial insects in public health due to their vector capacity and competence to transmit pathogens, including arboviruses, bacterias and parasites. Re-emerging and emerging arboviral diseases, such as yellow fever virus (YFV), dengue virus (DENV), zika virus (ZIKV), and chikungunya virus (CHIKV), constitute one of the most critical health public concerns in Latin America. These diseases present a significant incidence within the human settlements increasing morbidity and mortality events. Likewise, among the different genus of mosquito vectors of arboviruses, those of the most significant medical importance corresponds to Aedes and Culex. In Latin America, the mosquito vector species of YFV, DENV, ZIKV, and CHIKV are mainly Aedes aegypti and Ae. Albopictus. Ae. aegypti is recognized as the primary vector in urban environments, whereas Ae. albopictus, recently introduced in the Americas, is more prone to rural settings. This minireview focuses on what is known about the epidemiological impact of mosquito-borne diseases in Latin American countries, with particular emphasis on YFV, DENV, ZIKV and CHIKV, vector mosquitoes, geographic distribution, and vector-arbovirus interactions. Besides, it was analyzed how climate change and social factors have influenced the spread of arboviruses and the control strategies developed against mosquitoes in this continent.

Manifestaciones Oculares Posterior a Infecciones por Arbovirus

Introducción: Las infecciones por virus del Dengue, Chikungunya y Zika se han asociado a manifestaciones oculares como neurorretinitis, vasculitis, coroiditis, coriorretinitis, obstrucción venosa, edema macular, foveolitis, entre otras. Objetivo: El propósito del estudio es presentar una serie de casos de pacientes con afección ocular causada por infecciones por arbovirus. Metodología: Estudio es de carácter descriptivo, retrospectivo, en formato de reporte de serie de casos, describiendo los hallazgos de manifestaciones oculares secundarias a infecciones de arbovirus. Resultados: Se presentaron 13 pacientes con Dengue, 5 con Chikungunya y 4 con Zika. Doce de sexo masculino y diez femenino, con edades que oscilan entre 18 y 62 años. Conclusión: El Dengue es la infección con mayor recurrencia de manifestaciones oculares. El tratamiento con esteroides y anti-VEGF utilizado en base a la evidencia disponible demostró un impacto positivo en la evolución de la agudeza visual. El tratamiento conservador en pacientes con obstrucción de vena central de retina fue efectivo en aquellos que no presentaron la variante isquémica. La atrofia óptica fue la complicación más frecuente y presentó mejoría una vez el cuadro inflamatorio ha sido resuelto.

Serum Proteomics Reveals Alterations in Protease Activity, Axon Guidance, and Visual Phototransduction Pathways in Infants With In Utero Exposure to Zika Virus Without Congenital Zika Syndrome

In 2015, ZIKV infection attracted international attention during an epidemic in the Americas, when neurological disorders were reported in infants who had their mothers exposed to ZIKV during pregnancy. World Health Organization (WHO) epidemiological data show that 5 to 15% of neonates exposed to ZIKV in the uterus have complications included in abnormalities related to Congenital Zika Syndrome (CZS). The risk of complications after birth is not well documented, however, clinical evidence shows that 6% of infants exposed to ZIKV during pregnancy have complications present at birth, and this rate rises to 14% when medical monitoring is performed in all exposed infants, regardless of birth condition. Thus, the evaluation and monitoring of all exposed infants are of foremost importance as the development of late complications has been increasingly supported by clinical evidence. The identification of changes in protein profile of infants exposed to ZIKV without CZS could provide valuable findings to better understand molecular changes in this cohort. Here, we use a shotgun-proteomics approach to investigate alterations in the serum of infants without CZS symptoms but exposed to intrauterine ZIKV (ZIKV) compared to unexposed controls (CTRL). A complex pattern of differentially expressed proteins was identified, highlighting the dysregulation of proteins involved in axon orientation, visual phototransduction, and global protease activity in children exposed to ZIKV without CZS. These data support the importance of monitoring children exposed to ZIKV during gestation and without early CZS symptoms. Our study is the first to assess molecular evidence of possible late disorders in children victims of the ZIKV outbreak in the Americas. We emphasize the importance of medical monitoring of symptomatic and asymptomatic children, as apparently unexplained late neurological and eye disorders may be due to intrauterine ZIKV exposure.

History through the eyes of a pandemic

PURPOSE OF REVIEW

This review provides a historic perspective of the impact that major pandemics have had on human and their relationship with ophthalmology. The novel coronavirus epidemic is also analyzed, highlighting the relevance of the eye as a possible source of transmission, infection, and prognosis for the disease.

RESULTS

Smallpox is suspected to be present for more than 12 000 years. However, trachoma seems to be the first recorded ophthalmological infectious disease. The deadliest pandemics include the bubonic plague, smallpox, and Spanish flu. The CoVID-19 epidemic is still developing and measures need to be implemented to prevent further escalation of the crisis.

SUMMARY

Understanding the current facts in light of earlier historical evidence may help us prepare better to minimize the spread of infections in the future.

Cutaneous vaccination ameliorates Zika virus-induced neuro-ocular pathology via reduction of anti-ganglioside antibodies

Zika virus (ZIKV) causes moderate to severe neuro-ocular sequelae, with symptoms ranging from conjunctivitis to Guillain-Barré Syndrome (GBS). Despite the international threat ZIKV poses, no licensed vaccine exists. As ZIKV and DENV are closely related, antibodies against one virus have demonstrated the ability to enhance the other. To examine if vaccination can confer robust, long-term protection against ZIKV, preventing neuro-ocular pathology and long-term inflammation in immune-privileged compartments, BALB/c mice received two doses of unadjuvanted inactivated whole ZIKV vaccine (ZVIP) intramuscularly (IM) or cutaneously with dissolving microneedle patches (MNP). MNP immunization induced significantly higher B and T cell responses compared to IM vaccination, resulting in increased antibody titers with greater avidity for ZPIV as well as increased numbers of IFN-γ, TNF-α, IL- and IL-4 secreting T cells. When compared to IM vaccination, antibodies generated by cutaneous vaccination demonstrated greater neutralization activity, increased cross-reactivity with Asian and African lineage ZIKV strains (PRVABC59, FLR, and MR766) and Dengue virus (DENV) serotypes, limited ADE, and lower reactivity to GBS-associated gangliosides. MNP vaccination effectively controlled viremia and inflammation, preventing neuro-ocular pathology. Conversely, IM vaccination exacerbated ocular pathology, resulting in uncontrolled, long-term inflammation. Importantly, neuro-ocular pathology correlated with anti-ganglioside antibodies implicated in demyelination and GBS. This study highlights the importance of longevity studies in ZIKV immunization, and the need of exploring alternative vaccination platforms to improve the quality of vaccine-induced immune responses.

Zika circulation, congenital syndrome, and current guidelines: making sense of it all for the traveller

PURPOSE OF REVIEW

Zika virus (ZIKV) swept through the Americas and led to recognition of its neurotropism. Zika circulation elsewhere in the world, nonvector transmission including maternal-fetal/sexual/transfusion routes, and additional reports on congenital Zika syndrome (CZS) and Guillain-Barré syndrome (GBS) have been published.

RECENT FINDINGS

In 2018-2019, ZIKV transmission occurred in Cuba, India, and is suspected to appear sporadically in other countries. Maternal-fetal ZIKV transmission appears to occur in about 26% of ZIKV-infected pregnant women. The US ZIKV Pregnancy and Infant Registry identified 6% of live births to have at least one ZIKV-associated birth defect; 9% had at least one neurodevelopmental abnormality; 1% had both. Infectious virus was rarely isolated from semen of ZIKV-infected male patients beyond day 38 after symptom onset. Brazilian blood donations had low ZIKV prevalence in 2015-2016; in the United States, screening donations was cost-effective only in the high mosquito season in Puerto Rico.

SUMMARY

ZIKV transmission continues; many countries with competent mosquitoes are at risk. Transmission can occur without detection where surveillance is poor and laboratory capacity limited. Travelers are important sentinels. Variations exist among ZIKV strains and Aedes mosquitoes that influence competence for transmission. Maternal-fetal transmission results in significant rates of abnormality. Identification of infectious virus in semen clarifies sexual transmission risk, with updated recommendations for preconception planning. ZIKV neurotropism requires further research and long-term follow-up.

Cellular Organelles Reorganization During Zika Virus Infection of Human Cells

Zika virus (ZIKV) is an enveloped positive stranded RNA virus belonging to the genus Flavivirus in the family Flaviviridae that emerged in recent decades causing pandemic outbreaks of human infections occasionally associated with severe neurological disorders in adults and newborns. The intracellular steps of flavivirus multiplication are associated to cellular membranes and their bound organelles leading to an extensive host cell reorganization. Importantly, the association of organelle dysfunction with diseases caused by several human viruses has been widely reported in recent studies. With the aim to increase the knowledge about the impact of ZIKV infection on the host cell functions, the present study was focused on the evaluation of the reorganization of three cell components, promyelocytic leukemia nuclear bodies (PML-NBs), mitochondria, and lipid droplets (LDs). Relevant human cell lines including neural progenitor cells (NPCs), hepatic Huh-7, and retinal pigment epithelial (RPE) cells were infected with the Argentina INEVH116141 ZIKV strain and the organelle alterations were studied by using fluorescent cell imaging analysis. Our results have shown that these three organelles are targeted and structurally modified during ZIKV infection. Considering the nuclear reorganization, the analysis by confocal microscopy of infected cells showed a significantly reduced number of PML-NBs in comparison to uninfected cells. Moreover, a mitochondrial morphodynamic perturbation with an increased fragmentation and the loss of mitochondrial membrane potential was observed in ZIKV infected RPE cells. Regarding lipid structures, a decrease in the number and volume of LDs was observed in ZIKV infected cells. Given the involvement of these organelles in host defense processes, the reported perturbations may be related to enhanced virus replication through protection from innate immunity. The understanding of the cellular remodeling will enable the design of new host-targeted antiviral strategies.

Developmental Outcomes Among Young Children With Congenital Zika Syndrome in Brazil

IMPORTANCE

Although birth defects in children with congenital Zika syndrome (CZS) are expected to result in significant intellectual disabilities, the extent of delay and profiles of development have yet to be fully described.

OBJECTIVES

To describe the neurodevelopmental profiles of children with CZS and to test whether prenatal and postpartum characteristics were associated with the severity of developmental delays.

DESIGN, SETTING, AND PARTICIPANTS

This is a case series of the trajectories of developmental, behavioral, and medical needs of 121 young children with CZS who were assessed at a specialized rehabilitation center in Recife, Brazil, beginning in January 2018 as part of 5-year longitudinal study. Children were included if they had serologic confirmation of Zika virus and met clinical criteria accompanied by parental report of suspected exposure to Zika virus during pregnancy.

EXPOSURES

Prenatal Zika virus exposure.

MAIN OUTCOMES AND MEASURES

The Brazilian version of the Bayley Scales of Infant and Toddler Development, Third Edition, was administered by trained assessors as part of an initial comprehensive assessment battery. Caregiver interviews and medical record reviews were conducted to gather basic demographic information and medical comorbidities. Linear regression was used to identify potential factors for development.

RESULTS

The sample included 121 young children (mean [SD] age, 31.2 [1.9] months; 61 [50.4%] girls). At age approximately 2.5 years, nearly all children in this sample demonstrated profound developmental delays across all domains of functioning, with a mean (SD) developmental age equivalent to approximately 2 to 4 months (eg, cognitive domain, 2.24 [3.09] months; fine motor subscale, 2.15 [2.93] months; expressive language subscale, 2.30 [2.52] months). A relative strength was found in receptive language, with scores on this scale significantly higher than most other domains (eg, cognition: t = 3.73; P < .001; fine motor: t = 6.99; P < .001). Head circumference at birth was the single strongest factor associated with outcomes across all developmental domains (eg, cognitive: β = 1.41; SE, 0.67; P = .04; fine motor: β = 1.36; SE, 0.49; P = .007).

CONCLUSIONS AND RELEVANCE

The findings of this study provide important information regarding the severity of disability that these children and their families will experience. The findings also establish an initial point from which to monitor developmental trajectories, medical comorbidities (eg, seizures), effectiveness of interventions, and cumulative consequences on families.

Crosstalk between RNA Metabolism and Cellular Stress Responses during Zika Virus Replication

Zika virus (ZIKV) is a mosquito-borne virus associated with neurological disorders such as Guillain-Barré syndrome and microcephaly. In humans, ZIKV is able to replicate in cell types from different tissues including placental cells, neurons, and microglia. This intricate virus-cell interaction is accompanied by virally induced changes in the infected cell aimed to promote viral replication as well as cellular responses aimed to counteract or tolerate the virus. Early in the infection, the 11-kb positive-sense RNA genome recruit ribosomes in the cytoplasm and the complex is translocated to the endoplasmic reticulum (ER) for viral protein synthesis. In this process, ZIKV replication is known to induce cellular stress, which triggers both the expression of innate immune genes and the phosphorylation of eukaryotic translation initiation factor 2 (eIF2α), shutting-off host protein synthesis. Remodeling of the ER during ZIKV replication also triggers the unfolded protein response (UPR), which induces changes in the cellular transcriptional landscapes aimed to tolerate infection or trigger apoptosis. Alternatively, ZIKV replication induces changes in the adenosine methylation patterns of specific host mRNAs, which have different consequences in viral replication and cellular fate. In addition, the ZIKV RNA genome undergoes adenosine methylation by the host machinery, which results in the inhibition of viral replication. However, despite these relevant findings, the full scope of these processes to the outcome of infection remains poorly elucidated. This review summarizes relevant aspects of the complex crosstalk between RNA metabolism and cellular stress responses against ZIKV and discusses their possible impact on viral pathogenesis.

Impression Cytology Is a Non-invasive and Effective Method for Ocular Cell Retrieval of Zika Infected Babies: Perspectives in OMIC Studies

IMPORTANCE

Non-invasive techniques for retrieving ocular surface cells from babies infected by zika virus (ZIKV) during the gestational period remain to be determined.

OBJECTIVES

The aim of this study was to describe an optimized impression cytology method for the isolation of viable cells from Zika infected babies with and without Congenital Zika Syndrome (CZS) in satisfactory amount and quality to enable easy adoption in the field and application in the context of genomic and molecular approaches.

DESIGN SETTINGS AND PARTICIPANTS

Ocular surface samples were obtained with a hydrophilic nitrocellulose membrane (through optimized impression cytology method) from twelve babies referred to the Pediatric Service of the Antonio Pedro Hospital, Universidade Federal Fluminense (UFF), Niteroi, Rio de Janeiro, Brazil. After an authorized written informed consent from the parents, samples were collected from both eyes of 12 babies (4 babies with maternal ZIKV exposure during gestation and presence of clinical signs which included ocular abnormalities and microcephaly; 4 babies with maternal ZIKV exposure during gestation but no clinical signs; and 4 unaffected control babies with negative PCR for Zika virus and without clinical signs). Cells were used for microscopy analyses and evaluated for their suitability for downstream molecular applications in transcriptomic and proteomic experiments.

RESULTS

Our optimized impression cytology protocol enabled the capture of a considerable number of viable cells. The microscopic features of the conjunctival epithelial cells were described by both direct analysis of the membrane-attached cells and analysis of cytospinned captured cells using several staining procedures. Epithelial basal, polyhedral and goblet cells were clearly identified in all groups. All cases of ZIKV infected babies showed potential morphological alterations (cell keratinization, pyknosis, karyolysis, anucleation, and vacuolization). Molecular approaches were also performed in parallel. Genomic DNA and RNA were successfully isolated from all samples to enable the establishment of transcriptomic and proteomic studies.

CONCLUSIONS AND RELEVANCE

Our method proved to be a suitable, fast, and non-invasive tool to obtain ocular cell preparations from babies with and without Zika infection. The method yielded sufficient cells for detailed morphological and molecular analyses of samples. We discuss perspectives for the application of impression cytology in the context of ZIKV studies in basic and clinical research.

Cognitive Development of Infants Exposed to the Zika Virus in Puerto Rico

IMPORTANCE

Existing research has established a causal link between Zika virus (ZIKV) infection and severe birth defects or consequent health impairments; however, more subtle cognitive impairments have not been explored.

OBJECTIVE

To determine whether infants of mothers with at least 1 positive ZIKV test show differences in cognitive scores at ages 3 to 6 months and ages 9 to 12 months.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study recruited infants enrolled in existing ZIKV study cohorts associated with the Maternal-Infant Studies Center and the Puerto Rico Clinical and Translational Research Consortium at the University of Puerto Rico and from the broader San Juan metropolitan area. The study took place at the Puerto Rico Clinical and Translational Research Consortium at the University of Puerto Rico. Participants were recruited through convenience sampling if their mothers underwent ZIKV testing prenatally and were at the target ages during the study period. Infants who were born preterm (<36 weeks' gestational age), with low birth weight (<2500 g), or with a known genetic disorder were excluded. Infants were tested from ages 3 to 6 months or ages 9 to 12 months from May 2018 to April 2019. Data analysis was performed from March to April 2019.

EXPOSURES

Zika virus status was measured prenatally and in the early postnatal period using real-time polymerase chain reaction or a ZIKV IgM antibody capture enzyme-linked immunosorbent assay.

MAIN OUTCOMES AND MEASURES

The infants' development was assessed using the Mullen Scales of Early Learning (translated to Spanish and adapted for Puerto Rico), and assessors were blinded to each infant's ZIKV status.

RESULTS

A total of 65 study participants were included. The mean (SD) age of the infants at the time of cognitive testing was 8.98 (3.19) months. Most of the infants were white (55 [84.6%]) and Puerto Rican (64 [98.5%]); 38 of the infants were male (58.5%). General cognitive and domain-specific scores did not differ significantly between prenatally ZIKV-positive and ZIKV-negative infants except for receptive language score (mean difference = 5.52; t = 2.10; P = .04). Exposure to ZIKV (B = -5.69; β = -0.26 [95% CI -11.01 to -0.36]; P = .04) and a measure of Hurricane Maria exposure (time without water, B = -0.05; β = -0.27 [95% CI, -0.10 to -0.01]; P = .03) were both independently and significantly associated with receptive language scores after adjusting for key confounders.

CONCLUSIONS AND RELEVANCE

Although infants exposed to ZIKV prenatally showed unaffected motor and visually mediated cognitive development, they did show deficits in receptive language scores. Receptive language skills were also associated with the degree of exposure to Hurricane Maria, with those who spent more time without water after the hurricane having lower receptive language scores.

Comparative analysis of viral entry for Asian and African lineages of Zika virus

Zika virus (ZIKV) is an emerging pathogen with global health and economic impacts. ZIKV circulates as two major lineages, Asian or African. The Asian lineage has recently been associated with significant disease in humans. Numerous studies have revealed differences between African and Asian ZIKV strains with respect to cellular infectivity, pathogenesis, and immune activation. Less is known about the mechanism of ZIKV entry and whether viral entry differs between strains. Here, we characterized ZIKV entry with two Asian and two African strains. All viruses exhibited a requirement for clathrin-mediated endocytosis and Rab5a function. Additionally, all ZIKV strains tested were sensitive to pH in the range of 6.5-6.1 and were reliant on endosomal acidification for infection. Finally, we provide direct evidence that ZIKV primarily fuses with late endosomes. These findings contribute new insight into the ZIKV entry process and suggest that divergent ZIKV strains enter cells in a highly conserved manner.

Effects of Zika infection on growth

OBJECTIVES

To present the currently available evidence of the effects of congenital Zika virus infection on infant growth, to discuss possible intervening factors, and to describe preliminary data on this growth in a cohort of exposed children.

SOURCE OF DATA

Non-systematic review in PubMed, BVS, CAPES, Scopus, Web of Science, Cochrane and Google Scholar databases in the last 5 years, using the terms infection/disease by Zika virus and growth/nutrition/nutritional status/infant nutrition and nutritional needs. Additionally, the anthropometric data of the first 2.5 years of a cohort of children exposed to the Zika virus during pregnancy were reviewed.

SYNTHESIS OF DATA

Both intrauterine growth restriction and low birth weight were reported in series of cases of children with congenital Zika syndrome. The postnatal growth deficit of these children appears to be directly proportional to the degree of neurological impairment. The etiology is multifactorial, and nutritional and non-nutritional factors are probably involved. The data from the present cohort show that the head circumference evolution depends on this measurement at birth and that weight-height growth has a trend toward lower weight and length in children with congenital microcephaly and normocephalic at birth who develop some neurological abnormality.

CONCLUSIONS

The few existing data suggest that, in children with congenital Zika, the greater the degree of neurological impairment, the greater the impact on growth, whether or not associated with microcephaly at birth.

Visual function in infants with antenatal Zika virus exposure

PURPOSE

To report the findings of a cross-sectional study of visual function in infants with confirmed or suspected antenatal Zika virus (ZIKV) infection seen at a single referral center in Rio de Janeiro.

METHODS

Infants were examined following the ZIKV outbreak period at Instituto Fernandes Figueira/FIOCRUZ. Visual function was considered abnormal if an infant could not fix and follow a standardized high-contrast target (10 cm) by 3-6 months of age. Visual function and associations with structural eye abnormalities, central nervous system (CNS) abnormalities, microcephaly, and nystagmus were assessed. Sensitivity and specificity of screening criteria for structural eye abnormalities was assessed.

RESULTS

A total of 173 infants met inclusion criteria. Abnormal visual function was found in 52 infants (30.0%) and was significantly associated with eye abnormalities (40/52; OR = 44.2; 95% CI, 16.6-117.6), CNS abnormalities (50/52; OR = 64.0; 95% CI, 14.7-277.6), microcephaly (44/52; OR = 31.5; 95% CI, 12.7-77.8), and nystagmus (26/52; OR = 120.0; 95% CI, 15.6-924.5). Using microcephaly as screening criteria for the detection of eye abnormalities provided a sensitivity of 88.9% (95% CI, 76.0-96.3) and specificity of 82.8% (95% CI, 75.1-88.9). Using both abnormal visual function and microcephaly increased sensitivity to 100% (95% CI, 92.1-100.0) and decreased specificity to 80.5% (95% CI, 72.5-86.9).

CONCLUSIONS

Infants with suspected antenatal ZIKV infection and reduced visual function should be referred to an ophthalmologist. Visual function assessments are helpful in screening for antenatal ZIKV exposure in resource-limited settings and can identify infants who may benefit from visual habilitation.

Evolution of Two Major Zika Virus Lineages: Implications for Pathology, Immune Response, and Vaccine Development

Zika virus (ZIKV) became a public health emergency of global concern in 2015 due to its rapid expansion from French Polynesia to Brazil, spreading quickly throughout the Americas. Its unexpected correlation to neurological impairments and defects, now known as congenital Zika syndrome, brought on an urgency to characterize the pathology and develop safe, effective vaccines. ZIKV genetic analyses have identified two major lineages, Asian and African, which have undergone substantial changes during the past 50 years. Although ZIKV infections have been circulating throughout Africa and Asia for the later part of the 20th century, the symptoms were mild and not associated with serious pathology until now. ZIKV evolution also took the form of novel modes of transmission, including maternal-fetal transmission, sexual transmission, and transmission through the eye. The African and Asian lineages have demonstrated differential pathogenesis and molecular responses in vitro and in vivo. The limited number of human infections prior to the 21st century restricted ZIKV research to in vitro studies, but current animal studies utilize mice deficient in type I interferon (IFN) signaling in order to invoke enhanced viral pathogenesis. This review examines ZIKV strain differences from an evolutionary perspective, discussing how these differentially impact pathogenesis via host immune responses that modulate IFN signaling, and how these differential effects dictate the future of ZIKV vaccine candidates.