Congenital Zika Syndrome in a Brazil-Paraguay-Bolivia border region: Clinical features of cases diagnosed between 2015 and 2018

Auditory Neural Responses and Communicative Functioning in Children With Microcephaly Related to Congenital Zika Syndrome

OBJECTIVES

Children with microcephaly exhibit neurodevelopmental delays and compromised communicative functioning, yielding challenges for clinical assessment and informed intervention. This study characterized auditory neural function and communication abilities in children with microcephaly due to congenital Zika syndrome (CZS).

DESIGN

Click-evoked auditory brainstem responses (ABR) at fast and slow stimulation rates and natural speech-evoked cortical auditory evoked potentials (CAEP) were recorded in 25 Brazilian children with microcephaly related to CZS ( M age: 5.93 ± 0.62 years) and a comparison group of 25 healthy children ( M age: 5.59 ± 0.80 years) matched on age, sex, ethnicity, and socioeconomic status. Communication abilities in daily life were evaluated using caregiver reports on Vineland Adaptive Behavior Scales-3.

RESULTS

Caregivers of children with microcephaly reported significantly lower than typical adaptive functioning in the communication and socialization domains. ABR wave I latency did not differ significantly between the groups, suggesting comparable peripheral auditory function. ABR wave V absolute latency and waves I-V interwave latency were significantly shorter in the microcephaly group for both ears and rates. CAEP analyses identified reduced N2 amplitudes in children with microcephaly as well as limited evidence of speech sound differentiation, evidenced mainly by the N2 response latency. Conversely, in the comparison group, speech sound differences were observed for both the P1 and N2 latencies. Exploratory analyses in the microcephaly group indicated that more adaptive communication was associated with greater speech sound differences in the P1 and N2 amplitudes. The trimester of virus exposure did not have an effect on the ABRs or CAEPs.

CONCLUSIONS

Microcephaly related to CZS is associated with alterations in subcortical and cortical auditory neural function. Reduced ABR latencies differ from previous reports, possibly due to the older age of this cohort and careful assessment of peripheral auditory function. Cortical speech sound detection and differentiation are present but reduced in children with microcephaly. Associations between communication performance in daily life and CAEPs highlight the value of auditory evoked potentials in assessing clinical populations with significant neurodevelopmental disabilities.

Disease burden of congenital Zika virus syndrome in Brazil and its association with socioeconomic data

Zika virus (ZIKV) infection became a global public health concern, causing an epidemic in Latin America from 2015 to 2016, when a sudden increase in cases of microcephaly and other congenital anomalies was observed. In 2016, the Centers for Disease Control and Prevention and the World Health Organization defined congenital Zika-associated syndrome (CZS) as a set of congenital anomalies seen in children born to mothers with a history of gestational Zika fever, who have microcephaly as the most prevalent clinical sign. In order to describe the magnitude of CZS in Brazil, this study estimated the burden of disease due to CZS in Brazil using the disability-adjusted life years (DALY) indicator and other frequency measures, such as incidence and mortality rate, during the years 2015-2020. The association of these indicators with socioeconomic variables was also evaluated using Spearman's correlation coefficient. Choropleth maps were used to evaluate the spatial distribution of the indicators evaluated and the spatial autocorrelation was verified by the Bivariate Moran Local Index. From 2015 to 2020, 3,591 cases of CZS were confirmed in Brazil, with an incidence of 44.03 cases per 1000 live births, and a specific mortality of 12.35 deaths per 1000 live births. A global loss of 30,027.44 DALYs was estimated from 2015 to 2020. The Northeast region had the highest values for all health indicators assessed. Spatial correlation and autocorrelation analyses showed significant associations between health and socioeconomic indicators, such as per capita income, Gini index, illiteracy rate and basic sanitation. The study allowed us to have access to all reported cases of CZS, showing us the possible situation of the disease in Brazil; therefore, we believe that our results can help in the understanding of future studies.

Congenital anomalies during the 2015–2018 Zika virus epidemic: a population-based cross-sectional study

Background

Congenital anomalies are associated with several clinical and epidemiological complications. Following the Zika epidemic onset in Latin America, the incidence of congenital anomalies increased in Brazil. This study aimed to determine the frequency of congenital anomalies in one Brazilian state and assess potential factors associated with them.

Methods

This cross-sectional descriptive study was based on data concerning congenital anomalies recorded in the Brazilian Live-Born Information System during the Zika epidemic in Mato Grosso do Sul state from 2015 to 2018. Congenital anomalies were stratified according to year of birth and classified using ICD-10 categories.

Results

In total, 1,473 (0.85%) anomalies were registered. Within the number of cases recorded, microcephaly showed the greatest frequency and variations, with a 420% increase observed in the number of cases from 2015 to 2016. We identified an increase in the incidence of central nervous system anomalies, with the highest peak observed in 2016 followed by a subsequent decrease. Musculoskeletal, nervous, and cardiovascular system anomalies, and eye, ear, face, and neck anomalies represented 73.9% of all recorded anomalies. There was an increased chance of congenital anomalies in uneducated (odds ratio [OR] 5.56, 95% confidence interval [CI] 2.61–11.84) and Indigenous (OR 1.32, 95% CI 1.03–1.69) women, as well as among premature births (OR 2.74, 95% CI 2.39–3.13).

Conclusions

We estimated the incidence of congenital anomalies during the Zika epidemic. Our findings could help to support future research and intervention strategies in health facilities to better identify and assist children born with congenital anomalies.

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

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

A prospective study of neurodevelopmental trends between 3 and 24 months in normocephalic infants with prenatal Zika virus exposure: Evidence of emerging communication delays in the NATZIG cohort

Developmental trends between 3 and 24 months were assessed in 194 normocephalic infants with prenatal Zika virus exposure. Bayley Scales of Infant and Toddler Development Screening Test-3rd Edition cognitive scores remained in the typical range. Communication skills developed at a slower rate suggesting that neurodevelopmental delays may emerge at older ages.

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.

Plaque Reduction Neutralization Test (PRNT) in the Congenital Zika Syndrome: Positivity and Associations with Laboratory, Clinical, and Imaging Characteristics

The short duration of viremia, low blood viral load, inaccessibility to timely specific diagnostic tests, and cross-reactions with other flaviviruses have hindered laboratory confirmation of Congenital Zika Syndrome (CZS). This study analyzes the positivity of the plaque reduction neutralization test (PRNT) in children with clinical or imaging characteristics of CZS and its association with laboratory, clinical, and imaging characteristics. The 94 clinical cases of CZS submitted to the ZIKV PRNT₉₀ test were followed from 2016 to 2018. The mean age of children at PRNT₉₀ collection was 22 ± 6 months Standard Deviation. The ZIKV PRNT₉₀ was positive (titer ≥ 10) in 40 (42.5%) children. ZIKV PRNT₉₀ positivity was associated with severe microcephaly in newborns (p = 0.016), lower head circumference z-score at birth (p = 0.043) and 24 months of age (p = 0.031), and severe reduction of the cerebral parenchyma volume (p = 0.021), expressing greater disease severity. Negative PRNT₉₀ in children with characteristic signs of CZS may be due to false-negative results, indicating that the diagnosis of CZS should be primarily syndromic.

Neurological Development, Epilepsy, and the Pharmacotherapy Approach in Children with Congenital Zika Syndrome: Results from a Two-Year Follow-up Study

Clinical outcomes related to congenital Zika syndrome (CZS) include microcephaly accompanied by specific brain injuries. Among several CZS outcomes that have been described, epilepsy and motor impairments are present in most cases. Pharmacological treatment for seizures resulting from epilepsy is performed with anticonvulsant drugs, which in the long term are related to impairments in the child's neuropsychomotor development. Here, we describe the results from a two-year follow-up of a cohort of children diagnosed with CZS related to the growth of the head circumference and some neurological and motor outcomes, including the pharmacological approach, and its results in the treatment of epileptic seizures. This paper is part of a prospective cohort study carried out in the state of Mato Grosso Sul, Brazil, based on a Zika virus (ZIKV)-exposed child population. Our data were focused on the assessment of head circumference growth and some neurological and motor findings, including the description of seizure conditions and pharmacological management in two periods. Among the 11 children evaluated, 8 had severe microcephaly associated with motor impairment and/or epilepsy. Seven children were diagnosed with epilepsy. Of these, 3 had West syndrome. In four children with other forms of epilepsy, there was no pharmacological control.