Visual function in infants with antenatal Zika virus exposure

Virus as Teratogenic Agents

Viral infectious diseases are important causes of reproductive disorders, as abortion, fetal mummification, embryonic mortality, stillbirth, and congenital abnormalities in animals and in humans. In this chapter, we provide an overview of some virus, as important agents in teratology.We begin by describing the Zika virus, whose infection in humans had a very significant impact in recent years and has been associated with major health problems worldwide. This virus is a teratogenic agent in humans and has been classified as a public health emergency of international concern (PHEIC).Then, some viruses associated with reproductive abnormalities on animals, which have a significant economic impact on livestock, are described, as bovine herpesvirus, bovine viral diarrhea virus, Schmallenberg virus, Akabane virus, and Aino virus.For all viruses mentioned in this chapter, the teratogenic effects and the congenital malformations associated with fetus and newborn are described, according to the most recent scientific publications.

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.

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.

Characterizing Disabilities in Preschool Aged Children with Congenital Zika Virus Syndrome with the ICF Model

Understanding functioning and disabilities in children with Congenital Zika Syndrome (CZS) is essential for health planning. We describe disabilities present in children with CZS followed in a reference hospital in Rio de Janeiro, Brazil, based on the biopsychosocial model of the International Classification of Functioning, Disability and Health (ICF). This was a cohort study of children >3 years of age with CZS. Disability was characterized through outcomes related to ICF components assessed via clinical and motor development evaluations. Among 50 children, with a median age of 40 months, 47 (94%) presented with severe impairment and 46 (92%) had microcephaly. Damage to the head and neck was found in most children, with abnormal central nervous system imaging universally present. Most children had cognitive impairment (92%), muscle tone problems (90%), and speech deficits (94%). We found movement limitations in all categories but more pervasively (80−94%), in postural transfers and displacements. The main environmental factors identified in the ICF model were the use of products or substances for personal consumption and access to health services. Children with CZS have extremely high rates of disability beyond aged 3 years, particularly regarding motor activity. ICF-based models can contribute to the assessment of health domains.

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.

Long-Term Outcomes of Infants with Congenital Zika Virus Infection in Ecuador: A Retrospective Longitudinal Study

BACKGROUND

Few congenital Zika syndrome (CZS) cases have been notified in Ecuador and, to our knowledge, there are no significant published studies dealing with their clinical evolution. We present a detailed clinical characterization of 21 children with congenital Zika virus (ZIKV) infection born in Ecuador who were followed up until September 2019.

METHODS

We did a retrospective longitudinal study of children attended by the infectious disease specialists of Francisco Icaza Bustamante Children's Hospital (Guayaquil) due to congenital ZIKV infection suspicion. The inclusion criteria consisted of laboratory confirmed diagnosis of congenital ZIKV infection.

RESULTS

Sixteen of these 21 cases of congenital ZIKV infection showed clinical, neuroimaging and laboratory findings strongly suggestive of CZS and 5 children showed laboratory findings compatible with congenital ZIKV infection without congenital manifestations associated to CZS. All children with CZS showed neurodevelopmental delay, spasticity and hyperreflexia during follow-up, whereas the majority of them (14/15) experienced recurrent epileptic seizures and dysphagia (12/13). Two CZS cases died during follow-up. Visual evoked potential and hearing screening with acoustically evoked auditory brainstem response were abnormal in 50% and 37.5% of CZS cases, respectively. Congenital ZIKV infection without findings consistent with CZS at birth was not clinically relevant at 23 months of age in the five cases of our cohort.

CONCLUSIONS

Severe neurodevelopmental delay, severe microcephaly, epileptic seizures and dysphagia were present at 2 years of age in most CZS cases of our cohort.

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.

Time to Evaluate the Clinical Repercussions of Zika Virus Vertical Transmission? A Systematic Review

Background: Vertical transmission of Zika Virus (ZIKV) can be associated with several clinical features in newborn infants. The goal of the present review was to analyze the current state of knowledge regarding clinical repercussions following perinatal exposure to ZIKV in children up to 3 years of age. Methods: A systematic review of published studies was carried out, without the restriction of language or date of publication, identified in the databases PubMed, Virtual Health Library (BVS), Scopus, and Web of Science and the catalog for CAPES theses and dissertations. According to the proposed flowchart, the bibliographic search resulted in 1,563 papers. Of these, according to the eligibility criteria, 70 were selected for systematic review; all were published between 2016 and 2021. Results: Regarding clinical findings, 19 papers evaluated clinical imaging alterations, 21 ophthalmic manifestations, and 39 evaluated the central nervous system; of these, 15 analyzed neuro-psychomotor development. The remainder evaluated audiological (n = 14), nutritional (n = 14), orthopedic (n = 7), cardiorespiratory (n = 5), genitourinary (n = 3) or endocrinological (n = 1) manifestations. Conclusion: It is critical for studies to continue monitoring children with antenatal ZIKV exposure as they grow, given the unknown long-term repercussions of ZIKV and the recognized postnatal complications of this infection during pregnancy. Broader descriptions of observed clinical findings are also important in order to characterize the entire spectrum of disease in children. Systematic Review Registration: PROSPERO REGISTER: CRD42020205947.

Evolution of ocular defects in infant macaques following in utero Zika virus infection

Congenital Zika syndrome (CZS) is associated with microcephaly and various neurological, musculoskeletal, and ocular abnormalities, but the long-term pathogenesis and postnatal progression of ocular defects in infants are not well characterized. Rhesus macaques are superior to rodents as models of CZS because they are natural hosts of the virus and share similar immune and ocular characteristics, including blood–retinal barrier characteristics and the unique presence of a macula. Using a previously described model of CZS, we infected pregnant rhesus macaques with Zika virus (ZIKV) during the late first trimester and characterized postnatal ocular development and evolution of ocular defects in 2 infant macaques over 2 years. We found that one of them exhibited colobomatous chorioretinal atrophic lesions with macular and vascular dragging as well as retinal thinning caused by loss of retinal ganglion neuron and photoreceptor layers. Despite these congenital ocular malformations, axial elongation and retinal development in these infants progressed at normal rates compared with healthy animals. The ZIKV-exposed infants displayed a rapid loss of ZIKV-specific antibodies, suggesting the absence of viral replication after birth, and did not show any behavioral or neurological defects postnatally. Our findings suggest that ZIKV infection during early pregnancy can impact fetal retinal development and cause congenital ocular anomalies but does not appear to affect postnatal ocular growth.

Effects in the development of children exposed to zika virus in the fetal period: an integrative review

OBJECTIVE

To know the evidence available in the literature on the effects of the zika virus in children development after fetal exposure.

METHODS

This is an integrative literature review with 16 scientific articles found in five databases (PubMed, LILACS, CINAHL, Web of Science and Scopus), based on the guiding question: "What are the effects in the development of children aged 0 to 6 years exposed to the zika virus in the fetal period? The STROBE statement was used for data extraction and evaluation of primary studies.

RESULTS

Exposure to the zika virus in the fetal period resulted in several congenital anomalies and/or changes in the central nervous system: microcephaly, ocular problems, neurosensorial problems, ventriculomegaly, intracranial calcification, cardiopathy, arthrogryposis, among others.

CONCLUSION

The zika virus is neurotropic; its effect in the fetal nervous system causes irreparable damage to the child, so health professionals, especially nurses, must intensify maternal and also childcare.

Zika virus vertical transmission in children with confirmed antenatal exposure

We report Zika virus (ZIKV) vertical transmission in 130 infants born to PCR+ mothers at the time of the Rio de Janeiro epidemic of 2015–2016. Serum and urine collected from birth through the first year of life were tested by quantitative reverse transcriptase polymerase chain reaction (PCR) and/or IgM Zika MAC-ELISA. Four hundred and seven specimens are evaluated; 161 sera tested by PCR and IgM assays, 85 urines by PCR. Sixty-five percent of children (N = 84) are positive in at least one assay. Of 94 children tested within 3 months of age, 70% are positive. Positivity declines to 33% after 3 months. Five children are PCR+ beyond 200 days of life. Concordance between IgM and PCR results is 52%, sensitivity 65%, specificity 40% (positive PCR results as gold standard). IgM and serum PCR are 61% concordant; serum and urine PCR 55%. Most children (65%) are clinically normal. Equal numbers of children with abnormal findings (29 of 45, 64%) and normal findings (55 of 85, 65%) have positive results, p = 0.98. Earlier maternal trimester of infection is associated with positive results (p = 0.04) but not clinical disease (p = 0.98). ZIKV vertical transmission is frequent but laboratory confirmed infection is not necessarily associated with infant abnormalities.

Here, Brasil et al. investigate mother to child Zika virus (ZIKV) transmission rates in a large longitudinal cohort of pregnant ZIKV-positive women with their infants followed from the time of maternal infection through birth and onwards, finding high in utero transmission rates that do not predict clinical outcomes, suggesting follow-up of children with antenatal ZIKV exposure is necessary.

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.