Zika Virus Exposure Research Articles

Seguimento de crianças expostas intraútero ao vírus Zika na Região Metropolitana de Belém, Pará, Brasil

Programa Institucional de Bolsas de Iniciacao Cientifica da Universidade do Estado do Para (PIBIC/UEPA).

Neurodevelopment of children exposed intra-uterus by Zika virus: A case series.

The main goal of this manuscript was to investigate the neurodevelopment of children exposed by Zika virus in the intrauterine period who are asymptomatic at birth. Newborns with documented Zika virus exposure during the intrauterine period who were asymptomatic at birth were followed in the first two years of life for neurodevelopment using Bayley III test. Children were classified as having normal or delayed neurodevelopment for age based on most recent Bayley III evaluation results. Eighty-four infants were included in the study. The first Bayley III evaluation was performed at a mean chronological age of 9.7±3.1 month; 13 children (15%) had a delay in one of the three domains, distributed as follow: 10 (12%) in the language domain and 3 (3.5%) in the motor domain. The most recent Bayley III evaluation was performed at a mean age 15.3±3.1 months; 42 children (50%) had a delay in one of the three domains: 4 (5%) in cognition, 31 (37%) in language, and 20 (24%) in motor performance. There were no statistical differences in Gender, Gestational Age, Birth Weight and Head Circurference at birth between children with normal and delayed neurodevelopment for age. A very high proportion of children exposed ZIKV during pregnancy who were asymptomatic at birth demonstrated a delay in neurodevelopment, mainly in the language domain, the first two years of life.

Strong CD4 T Cell Responses to Zika Virus Antigens in a Cohort of Dengue Virus Immune Mothers of Congenital Zika Virus Syndrome Infants.

Background: There is an urgent need to understand the complex relationship between cross-reactive anti-viral immunity, disease susceptibility, and severity in the face of differential exposure to related, circulating Flaviviruses. Co-exposure to Dengue virus and Zika virus in Brazil is a case in point. A devastating aspect of the 2015–2016 South American Zika outbreak was the dramatic increase in numbers of infants born with microcephaly to mothers exposed to Zika virus during pregnancy. It has been proposed that this is more likely to ensue from Zika infection in women lacking cross-protective Dengue immunity. In this case series we measure the prevalence of Dengue immunity in a cohort of mothers exposed to Zika virus during pregnancy in the 2015–2016 Zika outbreak that gave birth to an infant affected by microcephaly and explore their adaptive immunity to Zika virus.Results: Fifty women from Sergipe, Brazil who gave birth to infants with microcephaly following Zika virus exposure during the 2015–16 outbreak were tested for serological evidence of Dengue exposure and IFNγ ELISpot spot forming cell (SFC) response to Zika virus. The majority (46/50) demonstrated Dengue immunity. IFNγ ELISpot responses to Zika virus antigens showed the following hierarchy: Env>NS1>NS3>C protein. Twenty T cell epitopes from Zika virus Env were identified. Responses to Zika virus antigens Env and NS1 were polyfunctional with cells making IFNγ, TNFα, IL-4, IL-13, and IL-10. In contrast, responses to NS5 only produced the immune regulatory TGFβ1 cytokine. There were SFC responses against Zika virus Env (1-20) and variant peptide sequences from West Nile virus, Dengue virus 1–4 and Yellow Fever virus.Conclusion: Almost all the women in our study showed serological evidence of Dengue immunity, suggesting that microcephaly can occur in DENV immune mothers. T cell immunity to Zika virus showed a multifunctional response to the antigens Env and NS1 and immune regulatory responses to NS5 and C protein. Our data support an argument that different viral products may skew the antiviral response to a more pro or anti-inflammatory outcome, with an associated impact on immunopathogenesis.

Congenital microcephaly unrelated to flavivirus exposure in coastal Kenya

Background: Zika virus (ZIKV) was first discovered in East Africa in 1947. ZIKV has caused microcephaly in the Americas, but it is not known whether ZIKV is a cause of microcephaly in East Africa. Methods: We used surveillance data from 11,061 live births at Kilifi County Hospital in coastal Kenya between January 2012 and October 2016 to identify microcephaly cases and conducted a nested case-control study to determine risk factors for microcephaly. Gestational age at birth was estimated based on antenatal ultrasound scanning (‘Scanned cohort’) or last menstrual period (‘LMP cohort’, including births ≥37 weeks’ gestation only). Controls were newborns with head circumference Z scores between >-2 and ≤2 SD that were compared to microcephaly cases in relation to ZIKV exposure and other maternal and newborn factors. Results: Of the 11,061 newborns, 214 (1.9%, 95%CI 1.69, 2.21) had microcephaly. Microcephaly prevalence was 1.0% (95%CI 0.64, 1.70, n=1529) and 2.1% (95%CI 1.81, 2.38, n=9532) in the scanned and LMP cohorts, respectively. After excluding babies <2500 g (n=1199) in the LMP cohort the prevalence was 1.1% (95%CI 0.93, 1.39). Microcephaly showed an association with being born small for gestational age (p<0.001) but not with ZIKV neutralising antibodies (p=0.6) or anti-ZIKV NS1 IgM response (p=0.9). No samples had a ZIKV neutralising antibody titre that was at least fourfold higher than the corresponding dengue virus (DENV) titre. No ZIKV or other flavivirus RNA was detected in cord blood from cases or controls. Conclusions: Microcephaly was prevalent in coastal Kenya, but does not appear to be related to ZIKV exposure; the ZIKV response observed in our study population was largely due to cross-reactive responses to DENV or other related flaviviruses. Further research into potential causes and the clinical consequences of microcephaly in this population is urgently needed.

A neonatal nonhuman primate model of gestational Zika virus infection with evidence of microencephaly, seizures and cardiomyopathy.

Zika virus infection during pregnancy is associated with miscarriage and with a broad spectrum of fetal and neonatal developmental abnormalities collectively known as congenital Zika syndrome (CZS). Symptomology of CZS includes malformations of the brain and skull, neurodevelopmental delay, seizures, joint contractures, hearing loss and visual impairment. Previous studies of Zika virus in pregnant rhesus macaques (Macaca mulatta) have described injury to the developing fetus and pregnancy loss, but neonatal outcomes following fetal Zika virus exposure have yet to be characterized in nonhuman primates. Herein we describe the presentation of rhesus macaque neonates with a spectrum of clinical outcomes, including one infant with CZS-like symptoms including cardiomyopathy, motor delay and seizure activity following maternal infection with Zika virus during the first trimester of pregnancy. Further characterization of this neonatal nonhuman primate model of gestational Zika virus infection will provide opportunities to evaluate the efficacy of pre- and postnatal therapeutics for gestational Zika virus infection and CZS.

Longitudinal visual acuity development in ZIKV-exposed children

To follow the visual acuity development of children exposed to or infected with the Zika virus (ZIKV) during gestation and to relate potential visual acuity deficits to their clinical condition. In this prospective study, visual acuity was measured via Teller Acuity Cards in three groups of children: (1) those with confirmed ZIKV exposure (ZE) through the mother only, (2) those with confirmed infection (ZI), and (3) unaffected controls. Visual acuity was measured 2-4 times in each child during the first 30months of age. The study included 22 children in the ZE group, 11 in the ZI group, and 27 controls. Visual acuity developed normally in both patient groups, including infected patients (ZI) that did not manifest clinical symptoms. In a small subgroup of patients with characteristics consistent with congenital Zika syndrome (CZS), visual acuity was within normative values, with the exception of single child with chorioretinal atrophy. In this southeastern Brazil study cohort, visual acuity development seemed to progress normally in infected children without CZS symptoms.

Neurodevelopmental Abnormalities in Children With In Utero Zika Virus Exposure Without Congenital Zika Syndrome

The number of children who were born to mothers with Zika virus (ZIKV) infection during pregnancy but who did not have apparent disability at birth is large, warranting the study of the risk for neurodevelopmental impairment in this population without congenital Zika syndrome (CZS). To investigate whether infants without CZS but who were exposed to ZIKV in utero have normal neurodevelopmental outcomes until 18 months of age. This cohort study prospectively enrolled a group of pregnant women with ZIKV in Atlántico Department, Colombia, and in Washington, DC. With this cohort, we performed a longitudinal study of infant neurodevelopment. Infants born between August 1, 2016, and November 30, 2017, were included if they were live born, had normal fetal brain findings on magnetic resonance imaging and ultrasonography, were normocephalic at birth, and had normal examination results without clinical evidence of CZS. Seventy-seven infants born in Colombia, but 0 infants born in the United States, met the inclusion criteria. Prenatal ZIKV exposure. Infant development was assessed by the Warner Initial Developmental Evaluation of Adaptive and Functional Skills (WIDEA) and the Alberta Infant Motor Scale (AIMS) at 1 or 2 time points between 4 and 18 months of age. The WIDEA and AIMS scores were converted to z scores compared with normative samples. Longitudinal mixed-effects regression models based on bootstrap resampling methods estimated scores over time, accounting for gestational age at maternal ZIKV infection and infant age at assessment. Results were presented as slope coefficients with 2-tailed P values based on z statistics that tested whether the coefficient differed from 0 (no change). Of the 77 Colombian infants included in this cohort study, 70 (91%) had no CZS and underwent neurodevelopmental assessments. Forty infants (57%) were evaluated between 4 and 8 months of age at a median (interquartile range [IQR]) age of 5.9 (5.3-6.5) months, and 60 (86%) underwent assessment between 9 and 18 months of age at a median (IQR) age of 13.0 (11.2-16.4) months. The WIDEA total score (coefficients: age = -0.227 vs age2 = 0.006; P < .003) and self-care domain score (coefficients: age = -0.238 vs age2 = 0.01; P < .008) showed curvilinear associations with age. Other domain scores showed linear declines with increasing age based on coefficients for communication (-0.036; P = .001), social cognition (-0.10; P < .001), and mobility (-0.14; P < .001). The AIMS scores were similar to the normative sample over time (95% CI, -0.107 to 0.037; P = .34). Nineteen of 57 infants (33%) who underwent postnatal cranial ultrasonography had a nonspecific, mild finding. No difference was found in the decline of WIDEA z scores between infants with and those without cranial ultrasonography findings except for a complex interactive relationship involving the social cognition domain (P < .049). The AIMS z scores were lower in infants with nonspecific cranial ultrasonography findings (-0.49; P = .07). This study found that infants with in utero ZIKV exposure without CZS appeared at risk for abnormal neurodevelopmental outcomes in the first 18 months of life. Long-term neurodevelopmental surveillance of all newborns with ZIKV exposure is recommended.

Embryotoxic impact of Zika virus in a rhesus macaque in vitro implantation model†.

Zika virus (ZIKV) infection is associated with adverse pregnancy outcomes in humans, and infection in the first trimester can lead to miscarriage and stillbirth. Vertical and sexual transmissions of ZIKV have been demonstrated, yet the impact of infection during the initial stages of pregnancy remains unexplored. Here we defined the impact of ZIKV on early embryonic and placental development with a rhesus macaque model. During in vitro fertilization (IVF), macaque gametes were inoculated with a physiologically relevant dose of 5.48log10 plaque-forming units (PFU) of Zika virus/H.sapiens-tc/PUR/2015/PRVABC59_v3c2. Exposure at fertilization did not alter blastocyst formation rates compared to controls. To determine the impact of ZIKV exposure at implantation, hatched blastocysts were incubated with 3.26log10, 4.26log10, or 5.26log10 PFU, or not exposed to ZIKV, followed by extended embryo culture for 10days. ZIKV exposure negatively impacted attachment, growth, and survival in comparison to controls, with exposure to 5.26log10 PFU ZIKV resulting in embryonic degeneration by day 2. Embryonic secretion of pregnancy hormones was lower in ZIKV-exposed embryos. Increasing levels of infectious virus were detected in the culture media post-exposure, suggesting that the trophectoderm is susceptible to productive ZIKV infection. These results demonstrate that ZIKV exposure severely impacts the zona-free blastocyst, whereas exposure at the time of fertilization does not hinder blastocyst formation. Overall, early stages of pregnancy may be profoundly sensitive to infection and pregnancy loss, and the negative impact of ZIKV infection on pregnancy outcomes may be underestimated.

Social Determinants of Health and the Hospitalized Child.

KP, a 2.5-year-old infant with cachexia, recently was admitted to our hospital. A year ago, the hospitalist team treated her for sequelae of Zika virus exposure: microcephaly, central diabetes insipidus, and failure to thrive. Sadly, here she was again, weighing less than her discharge weight when she was 18 months old. Her standardized weight for age had plummeted from an already poor −2.5 to an abysmal −5.5. How had our medical system failed this child? KP’s mother had dual US and Dominican citizenship, but was homeless and lacking many social supports in the United States. When her medically complex child was born, her social safety net collapsed. She realized she could not continue to bounce around between homes with such a medically fragile child. She had applied for Section 8 housing but had no idea when it would be approved, so she did the only thing that seemed reasonable: move back to the Dominican Republic to live with her parents. She ran out of desmopressin acetate (DDAVP) for her child in 3 months. She was forced to replace her child’s prescribed formula with powdered milk. She was hospitalized multiple times for aspiration pneumonia. KP returned to the United States with her mother, malnourished and weak, when their housing voucher was approved. Her health had dramatically declined, all because of housing insecurity and other key social determinants of health (SDOH). SDOH are “conditions in which people are born, grow, work, live, and age, and the wider set of forces and systems shaping the conditions of daily life.”1 There is some variability in opinion on what constitutes the SDOH roster, but the determinants generally include economic stability, education, social and community context, health and health care, neighborhood and built environment, limited English proficiency, immigration status, transportation barriers, racism and bias, household …

The Global Impact of the Zika Virus Pandemic: The Importance of Emergency Preparedness

The 2015 outbreak of Zika virus in Brazil led to a significant increase of neonatal microcephaly. While Zika virus was identified in Africa in the 1940s and was noted to be present in Asia, it was not until 2007 that there was a significant shift in the behavior of the virus. Reasons for this change in Zika virus behavior and pathogenesis could be due to a change in the virulence of the virus, and a new ability to infect the human host. Additionally, the changing habitat of mosquitoes along with increasing urbanization and changes of human habitats has increased the risk of Zika virus exposure. This review summarizes the response to the Zika pandemic and recommendations for interventions through the lens of the Sendai Framework for disaster risk reduction. Emergency preparedness focuses on lessening the likelihood and the impact of disasters. Preparedness encompasses the actions of mitigation, prevention, response, and recovery.

Zika Virus Peptide ELISA (ZIKV-NS2B-Concat ELISA) for Detection of IgG Antibodies to Zika Virus Infection.

Maternal Zika virus (ZIKV) infection during pregnancy can have profound teratogenic effects including microcephaly and intracranial calcification. In adults, infection may cause acute inflammatory polyneuropathy. These complications appear after resolution of viremia. Thus, molecular assays of blood are typically insufficient to make the link between ZIKV infection and disease. An alternative approach to testing for ZIKV exposure is serology. However, specific serological implication of ZIKV can be confounded by cross-reactivity with closely related flaviviruses. We used high-density peptide arrays that tile the proteomes of a selection of arboviruses to search for ZIKV-specific linear epitopes that would enable the development of accurate serological tests. We identified a 20-amino-acid-long diagnostic peptide sequence in the NS2B protein of ZIKV that was immunoreactive with sera from patients with a confirmed history of infection with ZIKV but not other flaviviruses. We then established a ZIKV peptide ELISA (ZIKV-NS2B-concat ELISA) that enables sensitive and specific diagnosis of exposure to ZIKV.

Normal Hearing Function in Children Prenatally Exposed to Zika Virus.

Introduction The association between prenatal Zika virus infection and hearing alterations in offspring has been the object of some studies, although few have assessed children without microcephaly. However, a current trend to include prenatal Zika virus exposure in the group of risk indicators for hearing loss is noted. Objective To present a series of 27 children prenatally exposed to the Zika virus submitted to multiple hearing assessments over time. Methods A cohort of children born to symptomatic mothers with laboratorial Zika virus infection confirmation during pregnancy was submitted to an otoacoustic emission test, auditory brainstem response test (automated, neurodiagnostic and frequency-specific), audiometry, and imitanciometry over a period of 36 months since birth. The hearing assessment was performed independently of the presence of microcephaly or other apparent signs of congenital Zika syndrome. Results The hearing tests presented predominantly normal results. Some children had signs of middle ear pathology. The only microcephalic child had normal electrophysiological tests, as well as preserved audiometric thresholds, but presented altered motor responses to sound. Conclusion Prenatal exposure to Zika virus does not always determine hearing impairment. This risk seems to be more associated to the severity of the central nervous system damage. Hearing screening and follow-ups of the affected children are important, as well as further research in this area.

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

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

Zika virus infection in pregnancy and infant growth, body composition in the first three months of life: a cohort study

The implications of Zika Virus exposure in pregnancy for early infant growth remains poorly described. The main goal of this study is to compare the growth, body composition, and feeding modality of infants in the first three months of life by prenatal Zika Virus exposure status. We selected an analytical cohort of 115 infants born without microcephaly, comprising 56 infants with qRT-PCR confirmed exposure to ZIKV during gestation and 59 infants born to women with presumptively no evidence of ZIKV in pregnancy. Infants were evaluated at birth, 1 and 3 months of age in terms of anthropometrics, body composition All the results were adjusted by maternal age, maternal BMI and gestational age. We observe no differences between anthropometric measurements at birth. Mothers in exposed group showed higher BMI. At 1 month and 3 months of age there were differences in mid arm circumference, arm muscle circumference and fat free mass. Weight and length was less in the ZIKV exposed in pregnancy infants and statistically different at 3 month of age. The findings of this investigation provide new evidence that ZIKV exposure in pregnancy may be associated with differences in body composition.

Congenital microcephaly unrelated to flavivirus exposure in coastal Kenya.

Background: Zika virus (ZIKV) was first discovered in East Africa in 1947. ZIKV has caused microcephaly in the Americas, but it is not known whether ZIKV is a cause of microcephaly in East Africa. Methods: We used surveillance data from 11,061 live births at Kilifi County Hospital in coastal Kenya between January 2012 and October 2016 to identify microcephaly cases and conducted a nested case-control study to determine risk factors for microcephaly. Gestational age at birth was estimated based on antenatal ultrasound scanning ('Scanned cohort') or last menstrual period ('LMP cohort', including births ≥37 weeks' gestation only). Controls were newborns with head circumference Z scores between >-2 and ≤2 SD that were compared to microcephaly cases in relation to ZIKV exposure and other maternal and newborn factors. Results: Of the 11,061 newborns, 214 (1.9%, 95%CI 1.69, 2.21) had microcephaly. Microcephaly prevalence was 1.0% (95%CI 0.64, 1.70, n=1529) and 2.1% (95%CI 1.81, 2.38, n=9532) in the scanned and LMP cohorts, respectively. After excluding babies <2500g (n=1199) in the LMP cohort the prevalence was 1.1% (95%CI 0.93, 1.39). Microcephaly showed an association with being born small for gestational age (p<0.001) but not with ZIKV neutralising antibodies (p=0.6) or anti-ZIKV NS1 IgM response (p=0.9). No samples had a ZIKV neutralising antibody titre that was at least fourfold higher than the corresponding dengue virus (DENV) titre. No ZIKV or other flavivirus RNA was detected in cord blood from cases or controls. Conclusions: Microcephaly was prevalent in coastal Kenya, but does not appear to be related to ZIKV exposure; the ZIKV response observed in our study population was largely due to cross-reactive responses to DENV or other related flaviviruses. Further research into potential causes and the clinical consequences of microcephaly in this population is urgently needed.

Subclinical in utero Zika virus infection is associated with interferon alpha sequelae and sex-specific molecular brain pathology in asymptomatic porcine offspring.

Zika virus (ZIKV) infection during human pregnancy may lead to severe fetal pathology and debilitating impairments in offspring. However, the majority of infections are subclinical and not associated with evident birth defects. Potentially detrimental life-long health outcomes in asymptomatic offspring evoke high concerns. Thus, animal models addressing sequelae in offspring may provide valuable information. To induce subclinical infection, we inoculated selected porcine fetuses at the mid-stage of development. Inoculation resulted in trans-fetal virus spread and persistent infection in the placenta and fetal membranes for two months. Offspring did not show congenital Zika syndrome (e.g., microcephaly, brain calcifications, congenital clubfoot, arthrogryposis, seizures) or other visible birth defects. However, a month after birth, a portion of offspring exhibited excessive interferon alpha (IFN-α) levels in blood plasma in a regular environment. Most affected offspring also showed dramatic IFN-α shutdown during social stress providing the first evidence for the cumulative impact of prenatal ZIKV exposure and postnatal environmental insult. Other eleven cytokines tested before and after stress were not altered suggesting the specific IFN-α pathology. While brains from offspring did not have histopathology, lesions, and ZIKV, the whole genome expression analysis of the prefrontal cortex revealed profound sex-specific transcriptional changes that most probably was the result of subclinical in utero infection. RNA-seq analysis in the placenta persistently infected with ZIKV provided independent support for the sex-specific pattern of in utero-acquired transcriptional responses. Collectively, our results provide strong evidence that two hallmarks of fetal ZIKV infection, altered type I IFN response and molecular brain pathology can persist after birth in offspring in the absence of congenital Zika syndrome.

2784. Increased Frontal Lobe Volume and Density in Macaques Exposed to Zika Virus In Utero

BackgroundIn utero Zika virus (ZIKV) infection causes birth defects and neurodevelopmental deficits in neonates. We reasoned that a translational macaque model of congenital ZIKV infection could define disease pathophysiology not possible in human clinical studies.MethodsWe inoculated 5 pregnant rhesus macaques with a Puerto Rican isolate of ZIKV (ZIKV-PRVABC59) during the first trimester, monitored infection with plasma viral RNA (vRNA) loads, and evaluated infants for birth defects and neurodevelopmental deficits during their first week of life. Assessments included neurobehavioral assessments, ophthalmic examinations, optical coherence tomography, electroretinography with visual evoked potentials, hearing examinations, brain magnetic resonance imaging (MRI), and tissue histopathological analyses.ResultsAll five pregnant dams demonstrated plasma viremia and seroconversion following ZIKV inoculation. One of the five pregnancies resulted in a stillbirth. All liveborn infants had decreased feeding volumes and weight gain compared with control infants. A comprehensive voxel-based morphometric comparison of ZIKV-exposed and control infant brain MRIs identified increased gray matter volume and density in the frontal lobe in the ZIKV-exposed infant group, which corresponds to the pharyngeal motor cortex responsible for coordinating swallowing. Ocular studies identified differences between ZIKV-exposed and control infants in retinal layer thicknesses (inner plexiform, outer nuclear layers, photoreceptor outer segment) and visual evoked potentials (increased amplitude of waveforms). While ZIKV vRNA was detected in the decidua of 2/5 pregnancies, no ZIKV vRNA was identified in infant tissues and none of the infants developed an anti-ZIKV IgM response.ConclusionIn utero ZIKV exposure resulted in decreased feeding volumes and weight gain, which may be related to the gray matter changes identified in the pharyngeal motor cortex. Changes in retinal layer thicknesses and increased cortical visual pathway waveform amplitude suggest vision may be impaired. These changes occurred despite the lack of evidence of vertical transmission, suggesting that ZIKV exposure without measurable vertical transmission affects fetal brain development.Disclosures All authors: No reported disclosures.

1874. Comparison of the Risk of Birth Defects in Live Births From Pregnant Women Infected and Not Infected by Zika Virus in Guadeloupe, 2016–2017

BackgroundIn the French Territories in the Americas (FTA), the risk of birth defects possibly associated with Zika virus (ZIKV) infection was estimated at 7% among fetuses/infants in a cohort of 546 women who developed a symptomatic RT-PCR confirmed ZIKV infection during pregnancy (NEJM 2018;378:985–94). There was no concomitant prospective cohort of pregnant women without ZIKV infection to use as a control group.MethodsIn Guadeloupe, one of the 3 FTAs that participated in the FTA cohort study, pregnant women were recruited at the time of delivery and tested for ZIKV infection. Women who had a confirmed negative IgG serology test for ZIKV at delivery and no other positive ZIKV test during pregnancy were considered to be ZIKV noninfected. Information on the course of the pregnancy was collected retrospectively and outcomes of live born infants of ZIKV noninfected women were analyzed, using the same definition criteria as those used for the FTA cohort study. Pregnancy outcomes were compared with those of the 241 ZIKV-exposed live born infants in Guadeloupe, extracted from the FTA cohort.ResultsOf the 490 live born infants without in-utero exposure to ZIKV, 42 infants (8.6%) had neurological abnormalities that were described as “potentially linked to ZIKV infection”; all but one of these were microcephaly without any other brain or clinical abnormalities. The proportion of such abnormalities was not statistically different from that observed in the 241 live born infants with ZIKV exposure (6.6%, P = 0.36). When re-considering the combined 8 fetuses and 241 infants of women with confirmed ZIKV infection in Guadeloupe from the FTA cohort, only two (0.8%) live born infants and three (1.2%) medically aborted fetuses had birth defects that could still be linked to ZIKV infection.ConclusionIsolated anthropometric and other mild neurological abnormalities had the same prevalence among live born infants with and without in utero ZIKV exposure. The high prevalence of isolated microcephaly among ZIKV noninfected women in our study population suggests that the sensitive definition for microcephaly, using a −2 SD cut-off with international growth curves, may lead to an overestimate of the rate of neurological complications of ZIKV infection during pregnancy.Disclosures All Authors: No reported Disclosures.

2806. Follow-up of Children with Confirmed Perinatal Zika Virus Exposure: The First 2-year experience in the Costa Rican Tertiary Pediatric Hospital

BackgroundCosta Rica (CR) has local transmission of Zika Virus (ZIKV) Infection since February 2016. Perinatal exposure (PE) and infection (PI) cases have been documented. Following a national protocol, reporting and follow-up of patients is mandatory. 2018 data of CR reported 272 women with confirmed ZIKV infection during pregnancy. Even though neurological sequelae are described in PI, including microcephaly, affected patients can develop symptoms within months after birth with development, language, and behavior alterations.MethodsRetrospective descriptive study of patients born from August 1, 2016 until July 31, 2018, with laboratory confirmed PE. Follow-up was performed at referral hospital.Results101 patients were enrolled (37% of all national confirmed perinatal ZIKV exposure during study period). Median age of first evaluation was 5 months (range: 0.6–21). 86/101 (86%) were classified as adequate term infants. 34/101 (33.7%) mothers got infected at first trimester, 55 (54.4%) at second, and 11 (10.8%) at third trimester. No data available in one. 8/101 (8%) patients had microcephaly at birth, with only 3/101 (3%) with persistence at follow-up, and 3/101 (3%) developed it later (after 9 months). 3/101 (3%) had confirmed congenital ZIKV syndrome (laboratory confirmation in symptomatic children), and 2 (2%) congenital ZIKV infection (laboratory confirmation in asymptomatic child). 6/101 (6%) had tone abnormalities and global development delay. 9 (9%) had central nervous system (CNS) ultrasound abnormalities, and 3 (3%) developed seizures. 2 (2%) had visual abnormalities, 1 (1%) had hearing impairment, 4 (4%) developed eating abnormalities, 6 (6%) developed language delay, and 4 (4%) had hyperactive behavior. All findings were divided according to maternal trimester of infection.ConclusionPI is a health problem in CR. Microcephaly at is infrequent, with international data showing it affects less than 1% of newborns. Most motor and development delay were documented in patients infected early during pregnancy, but specific language and behavior abnormalities also affected patients with later PE. Mortality was not documented, but significant CNS abnormalities were evident in congenital ZIKV syndrome patients.Disclosures All authors: No reported disclosures.

Productive Infection of Mouse Mammary Glands and Human Mammary Epithelial Cells by Zika Virus.

Zika virus (ZIKV) belongs to the large category of arboviruses. Surprisingly, several human-to-human transmissions of ZIKV have been notified, either following sexual intercourse or from the mother to fetus during pregnancy. Importantly, high viral loads have been detected in the human breast milk of infected mothers, and the existence of breastfeeding as a new mode of mother-to-child transmission of ZIKV was recently hypothesized. However, the maternal origin of infectious particles in breast milk is currently unknown. Here, we show that ZIKV disseminates to the mammary glands of infected mice after both systemic and local exposure with differential kinetics. Ex vivo, we demonstrate that primary human mammary epithelial cells were sensitive and permissive to ZIKV infection in this study. Moreover, by using in vitro models, we prove that mammary luminal- and myoepithelial-phenotype cell lines are both able to produce important virus progeny after ZIKV exposure. Our data suggest that the dissemination of ZIKV to the mammary glands and subsequent infection of the mammary epithelium could be one mechanism of viral excretion in human breast milk.