Alterations in visual acuity and visual development in infants 1-24 months old either exposed to or infected by Zika virus during gestation, with and without microcephaly

Viral infections and pathogenesis of glaucoma: a comprehensive review

Glaucoma is a leading cause of irreversible blindness worldwide, caused by the gradual degeneration of retinal ganglion cells and their axons. While glaucoma is primarily considered a genetic and age-related disease, some inflammatory conditions, such as uveitis and viral-induced anterior segment inflammation, cause secondary or uveitic glaucoma. Viruses are predominant ocular pathogens and can impose both acute and chronic pathological insults to the human eye. Many viruses, including herpes simplex virus, varicella-zoster virus, cytomegalovirus, rubella virus, dengue virus, chikungunya virus, Ebola virus, and, more recently, Zika virus (ZIKV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), have been associated with sequela of either primary or secondary glaucoma. Epidemiological and clinical studies suggest the association between these viruses and subsequent glaucoma development. Despite this, the ocular manifestation and sequela of viral infections are not well understood. In fact, the association of viruses with glaucoma is considered relatively uncommon in part due to underreporting and/or lack of long-term follow-up studies. In recent years, literature on the pathological spectrum of emerging viral infections, such as ZIKV and SARS-CoV-2, has strengthened this proposition and renewed research activity in this area. Clinical studies from endemic regions as well as laboratory and preclinical investigations demonstrate a strong link between an infectious trigger and development of glaucomatous pathology. In this article, we review the current understanding of the field with a particular focus on viruses and their association with the pathogenesis of glaucoma.

Natural Products and Derivatives as Potential Zika virus Inhibitors: A Comprehensive Review

Zika virus (ZIKV) is an arbovirus whose infection in humans can lead to severe outcomes. This article reviews studies reporting the anti-ZIKV activity of natural products (NPs) and derivatives published from 1997 to 2022, which were carried out with NPs obtained from plants (82.4%) or semisynthetic/synthetic derivatives, fungi (3.1%), bacteria (7.6%), animals (1.2%) and marine organisms (1.9%) along with miscellaneous compounds (3.8%). Classes of NPs reported to present anti-ZIKV activity include polyphenols, triterpenes, alkaloids, and steroids, among others. The highest values of the selectivity index, the ratio between cytotoxicity and antiviral activity (SI = CC₅₀/EC₅₀), were reported for epigallocatechin gallate (SI ≥ 25,000) and anisomycin (SI ≥ 11,900) obtained from Streptomyces bacteria, dolastane (SI = 1246) isolated from the marine seaweed Canistrocarpus cervicorni, and the flavonol myricetin (SI ≥ 862). NPs mostly act at the stages of viral adsorption and internalization in addition to presenting virucidal effect. The data demonstrate the potential of NPs for developing new anti-ZIKV agents and highlight the lack of studies addressing their molecular mechanisms of action and pre-clinical studies of efficacy and safety in animal models. To the best of our knowledge, none of the active compounds has been submitted to clinical studies.

Visual findings in children exposed to Zika in utero in Nicaragua

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

Visual Acuity alterations in heavily impaired Congenital Zika Syndrome (CZS) children

Introduction

This study aimed to assess visual acuity (VA) in Congenital Zika Syndrome (CZS)-children to evaluate visual loss. To that end we evaluated 41 CZS - children, from Rio de Janeiro using Teller Acuity Cards.

Methods

To asses VA, we evaluated 41 CZS - children, from Rio de Janeiro using Teller Acuity Cards. The children had Zika virus-infection confirmed by reverse transcription-polymerase chain reaction (RT-PCR) or clinical evaluation.

Results

In 39 out of 41 (95%) children, the VA scores were below normative values, while in 10 cases, VA was only marginally below normal; in the remaining 29 cases, VA was more than 0.15 logMAR below the lower limit. There was no correlation between VA and the cognitive domain tasks, although there was a correlation between VA and motor domain tasks. Thirty-seven children performed at least one task in the cognitive set, while fourteen children did not perform any task in the motor set. Children with VA above the lower limit performed better in the cognitive and motor tasks.

Discussion

We concluded that ZIKV- infected children with CZS were highly VA impaired which correlated with motor performance, but not with cognitive performance. Part of the children had VA within the normal limits and displayed better performance in the cognitive and motor sets. Therefore, even if heavily impaired, most children had some degree of VA and visual function.

Fundus Changes in the Offspring of Mothers With Confirmed Zika Virus Infection During Pregnancy in French Guiana, Guadeloupe, and Martinique, French West Indies

Importance

Most ocular lesions have been described for children with congenital Zika syndrome. The frequency of finding ocular abnormalities is unknown among children exposed to Zika virus (ZIKV) during pregnancy. This study was conducted on newborns whose mothers were positive for ZIKV, confirmed with reverse-transcription polymerase chain reaction (RT-PCR) testing.

Objective

To report ocular fundus manifestations in newborns with congenital ZIKV exposure in French Guiana, Martinique, and Guadeloupe, French West Indies, to assess its prevalence. Risk factors, such as the presence of extraocular fetopathies and the gestational term at infection, were sought.

Design, Setting, and Participants

This was a cross-sectional multicentric study, conducted from August 1, 2016, to April 30, 2019, for which data were collected prospectively. The study inception was at the beginning of 2016 from the onset of the ZIKV epidemic in the French West Indies. Newborns whose mothers tested positive (by RT-PCR) for ZIKV during pregnancy were included.

Interventions

Fundus examination was performed using widefield retinal imaging after pupil dilation. Infection date, delivery mode, and newborn measurements were collected.

Main Outcomes and Measures

Anomalies of the vitreous, choroid, retina, and optic disc.

Results

A total of 330 children (mean [SD] age, 68 [IQR, 22-440] days; 170 girls [51.5%]) were included. Eleven children (3.3%) had perivascular retinal hemorrhages, and 3 (0.9%) had lesions compatible with congenital ZIKV infection: 1 child had torpedo maculopathy, 1 child had a chorioretinal scar with iris and lens coloboma, and 1 child had a chorioretinal scar. Retinal hemorrhages were found at childbirth during early screening. Lesions compatible with congenital ZIKV infection were not associated with the presence of extraocular fetopathy. Microcephaly was not associated with lesions compatible with congenital ZIKV infection (odds ratio [OR], 9.1; 95% CI, 0.8-105.3; P = .08), but severe microcephaly was associated with an OR of 81 (95% CI, 5.1-1297.8; P = .002).

Conclusions and Relevance

Results of this cross-sectional study suggest that the ocular anomalies found may be associated with ZIKV in 0.9% of the exposed population. Ocular lesions were rare, affected mostly the choroid and retina, and seemed to be associated with choroiditis-related scarring that developed during fetal growth.

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.

Ocular Manifestations of Chikungunya Infection: A Systematic Review

The Chikungunya virus (CHIKV) can cause long lasting symptoms and manifestations. However, there is little information on which ocular ones are most frequent following infection. We performed a systematic review (registered in the International Prospective Register of Systematic Reviews; no CRD42020171928) to establish the most frequent ocular manifestations of CHIKV infection and their associations with gender and age. Articles published until September 2020 were selected from PubMed, Scielo, Cochrane and Scopus databases. Only studies with CHIKV-infected patients and eye alterations were included. Reviews, descriptive studies, or those not investigating the human ocular manifestations of CHIKV, those with patients with other diseases and infections, abstracts and studies without relevant data were excluded. Twenty-five studies were selected for inclusion. Their risk of bias was evaluated by a modified Newcastle-Ottawa scale. The most frequent ocular symptoms of CHIKV infection included ocular pain, inflammation and reduced visual acuity, whilst conjunctivitis and optic neuritis were the most common manifestations of the disease. These occurred mostly in individuals of 42 ± 9.5 years of age and woman. The few available reports on CHIKV-induced eye manifestations highlight the need for further research in the field to gather more substantial evidence linking CHIKV infection, the eye and age/gender. Nonetheless, the data emphasizes that ocular alterations are meaningful occurrences of CHIKV infection which can substantially affect quality of life.

Ocular Findings and Visual Function in Children Examined during the Zika Health Brigade in the US Virgin Islands, March 2018

Among children born with laboratory-confirmed Zika virus (ZIKV) infection, visual impairment (VI) can occur despite normal ocular structure. The objective of this report is to describe ocular findings and visual function among children examined during the Department of Health Zika Health Brigade (ZHB) in the United States Virgin Islands in March 2018. This analysis is based on a retrospective chart review of children eligible to participate in the ZHB (i.e., part of the US Zika Pregnancy and Infant Registry) and who were examined by ophthalmologists. Eighty-eight children attended the ZHB. This report includes 81 children [48 (59.3%) males] whose charts were located [average gestational age = 37.6 weeks (range: 27.6–41.3) and average adjusted age at examination = 9.1 months (range: 0.9–21.9)]. Of those examined, 5/81 (6.2%) had microcephaly at birth, 2/81 (2.5%) had a structural eye abnormality, and 19/72 (26.4%) had VI. Among children with normal ocular structure and neurologic examination, 13/51 (25.5%) had VI. Despite a low incidence of abnormal ocular structure and microcephaly, about a quarter of children examined had VI. Our findings emphasize that ophthalmological examinations should be performed in all children with suspicion for antenatal ZIKV infection, even children with normal ocular structure and neurologic examination.

Women's Health Perceptions and Beliefs Related to Zika Virus Exposure during the 2016 Outbreak in Northern Brazil

During the 2016 Zika pandemic in Brazil, women's perceptions of infection risk, ability to adhere to Zika prevention strategies, or access to services following exposure were not emphasized in the public health response. Women in Fortaleza, Brazil, responded to a questionnaire on social factors related to perceived Zika risk and access to health care in June 2016. Data were coded using prespecified categories, and response frequency was reported. Of 37 respondents, most reported a lack of public services to support mosquito control (n = 19) or delayed access to reproductive health care (n = 14). Only 22% described specific maternal risks or fetal outcomes as a consequence of Zika infection. Respondents indicated an overall disconnect between public health efforts and women's perceptions of their reproductive control, including limited support concerning microcephaly in infants. Interventions targeting Zika may require a greater emphasis on strengthening health systems and infrastructure to realistically prevent transmission.

Zika virus infection as a cause of congenital brain abnormalities and Guillain-Barré syndrome: A living systematic review

Background: The Zika virus (ZIKV) caused a large outbreak in the Americas leading to the declaration of a Public Health Emergency of International Concern in February 2016. A causal relation between infection and adverse congenital outcomes such as microcephaly was declared by the World Health Organization (WHO) informed by a systematic review structured according to a framework of ten dimensions of causality, based on the work of Bradford Hill. Subsequently, the evidence has continued to accumulate, which we incorporate in regular updates of the original work, rendering it a living systematic review.

Methods: We present an update of our living systematic review on the causal relation between ZIKV infection and adverse congenital outcomes and between ZIKV and GBS for four dimensions of causality: strength of association, dose-response, specificity, and consistency. We assess the evidence published between January 18, 2017 and July 1, 2019.

Results: We found that the strength of association between ZIKV infection and adverse outcomes from case-control studies differs according to whether exposure to ZIKV is assessed in the mother (OR 3.8, 95% CI: 1.7-8.7, I ²=19.8%) or the foetus/infant (OR 37.4, 95% CI: 11.0-127.1, I ²=0%). In cohort studies, the risk of congenital abnormalities was 3.5 times higher after ZIKV infection (95% CI: 0.9-13.5, I ²=0%). The strength of association between ZIKV infection and GBS was higher in studies that enrolled controls from hospital (OR: 55.8, 95% CI: 17.2-181.7, I ²=0%) than in studies that enrolled controls at random from the same community or household (OR: 2.0, 95% CI: 0.8-5.4, I ²=74.6%). In case-control studies, selection of controls from hospitals could have biased results.

Conclusions: The conclusions that ZIKV infection causes adverse congenital outcomes and GBS are reinforced with the evidence published between January 18, 2017 and July 1, 2019.