In utero negativization of Zika virus in a foetus with serious central nervous system abnormalities

Neurological Short-Term Outcomes of a Cohort of Children Born to Zika Virus-Infected Mothers in Barcelona

Zika virus (ZIKV) is a vector-borne flavivirus with a known teratogenic effect, yet the full spectrum has not been delineated. Studies on endemic areas tried to characterize the clinical outcomes of ZIKV intrauterine exposure. We aimed to describe early neurodevelopmental outcomes on prenatally ZIKV-exposed children in a non-endemic ZIKV area. This is a prospective observational cohort study conducted from May 2016 to December 2021 at Hospital Universitari Vall d’Hebron in Barcelona, Catalonia, Spain. We monitored for up to 24 months 152 children extracted from a pregnant women cohort with suspected ZIKV infection; eleven women (11/150; 7.3%) fulfilled the criteria for a confirmed ZIKV infection. Among the 152 children included, we describe two cases of congenital ZIKV syndrome (CZS) born from women with a confirmed ZIKV infection. Additionally, we describe five cases of other potentially ZIKV-related outcomes (OPZROs), all with normal birth cranial circumference and born to women with probable ZIKV infection. The low exposed prevalence of adverse outcomes in asymptomatic children at birth in a non-endemic area suggests that close follow-up should be addressed by primary care pediatricians instead of pediatric specialists. Further studies are needed to assess the effects of ZIKV intrauterine exposure beyond two years of life.

Clinical phenotype in infants with negative Zika virus immunoglobulin M testing born to mothers with confirmed Zika virus infection during pregnancy

BACKGROUND

Recommended testing for both infants with Zika-associated birth defects (i.e., microcephaly and selected brain or eye anomalies) and infants without birth defects whose mothers had laboratory evidence of possible Zika virus (ZIKV) infection during pregnancy includes nucleic acid amplification testing (NAAT) and immunoglobulin M (IgM) testing within days after birth. Brain and eye defects highly specific for congenital ZIKV infection have been described; sporadic reports have documented negative ZIKV testing in such infants.

METHODS

Infants from the U.S. Zika Pregnancy and Infant Registry and Zika Birth Defects Surveillance with Zika-associated birth defects and maternal and infant laboratory testing for ZIKV and two congenital infections (i.e., cytomegalovirus [CMV] and toxoplasmosis) were reviewed for phenotype and laboratory results. Infants with at least one defect considered highly specific for congenital ZIKV infection were designated as having congenital Zika syndrome (CZS) clinical phenotype for this study.

RESULTS

Of 325 liveborn infants with Zika-associated birth defects and laboratory evidence of maternal ZIKV infection, 33 (10%) had CZS clinical phenotype; 172 (53%) had ZIKV IgM testing with negative or no ZIKV NAAT. ZIKV IgM was negative in the remaining 121 infants, and for 90%, testing for CMV and toxoplasmosis was missing/incomplete. Among 11 infants testing negative for ZIKV IgM, CMV, and toxoplasmosis, 2 infants had CZS clinical phenotype.

CONCLUSIONS

These data add support to previous reports of negative ZIKV IgM testing in infants with clear maternal and phenotypic evidence of congenital ZIKV infection. Follow-up care consistent with the diagnosis is recommended regardless of infant ZIKV test results.

Zika virus infection in pregnancy: a protocol for the joint analysis of the prospective cohort studies of the ZIKAlliance, ZikaPLAN and ZIKAction consortia

INTRODUCTION

Zika virus (ZIKV) infection in pregnancy has been associated with microcephaly and severe neurological damage to the fetus. Our aim is to document the risks of adverse pregnancy and birth outcomes and the prevalence of laboratory markers of congenital infection in deliveries to women experiencing ZIKV infection during pregnancy, using data from European Commission-funded prospective cohort studies in 20 centres in 11 countries across Latin America and the Caribbean.

METHODS AND ANALYSIS

We will carry out a centre-by-centre analysis of the risks of adverse pregnancy and birth outcomes, comparing women with confirmed and suspected ZIKV infection in pregnancy to those with no evidence of infection in pregnancy. We will document the proportion of deliveries in which laboratory markers of congenital infection were present. Finally, we will investigate the associations of trimester of maternal infection in pregnancy, presence or absence of maternal symptoms of acute ZIKV infection and previous flavivirus infections with adverse outcomes and with markers of congenital infection. Centre-specific estimates will be pooled using a two-stage approach.

ETHICS AND DISSEMINATION

Ethical approval was obtained at each centre. Findings will be presented at international conferences and published in peer-reviewed open access journals and discussed with local public health officials and representatives of the national Ministries of Health, Pan American Health Organization and WHO involved with ZIKV prevention and control activities.

Fetal Transient Skin Edema in Two Pregnant Women With Coronavirus Disease 2019 (COVID-19)

BACKGROUND

The risk of vertical transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains unknown. Positive reverse-transcription polymerase chain reaction (RT-PCR) test results for SARS-CoV-2 infection in neonates and placental tissue have been reported, and immunoglobulin M antibodies have been detected in neonates born to mothers with infection.

CASES

The first case is a woman at 22 3/7 weeks of gestation with coronavirus disease 2019 (COVID-19) who was admitted to the intensive care unit. In the second case, the patient remained at home with mild symptoms, starting at 20 weeks of gestation. In both cases, fetal skin edema was observed on ultrasound examination while maternal SARS-COV-2 RT-PCR test results were positive and resolved when maternal SARS-COV-2 RT-PCR test results became negative. The RT-PCR test result for SARS-CoV-2 in amniotic fluid was negative in both cases. The two pregnancies are ongoing and uneventful.

CONCLUSION

Transient fetal skin edema noted in these two patients with COVID-19 in the second trimester may represent results of fetal infection or altered fetal physiology due to maternal disease or may be unrelated to the maternal illness.

Role of Prenatal Ultrasonography and Amniocentesis in the Diagnosis of Congenital Zika Syndrome: A Systematic Review

OBJECTIVE

To examine the relationship between prenatal diagnostics (ultrasound examination and amniotic fluid Zika virus testing) and postnatal congenital Zika syndrome abnormalities.

DATA SOURCES

Systematic searches were performed in 27 databases, including ClinicalTrials.gov, from inception to July 1, 2019, for articles with the keywords "Zika," "prenatal," "ultrasound," and "amniocentesis."

METHODS OF STUDY SELECTION

A total of 3,049 unique records were identified. Two reviewers independently assessed titles, abstracts, and full texts for relevance; 84 articles met the inclusion criteria. These articles describe 402 mother-fetus or mother-neonate dyads; 385 were included in the review of prenatal ultrasound examination, and 56 in the review of amniocentesis (39 in both).

TABULATION, INTEGRATION, AND RESULTS

Among 195 fetuses with congenital Zika syndrome findings on prenatal ultrasound examination, postnatal congenital Zika syndrome abnormalities were reported for 153 (78%; 95% CI 7-84%). High proportions of microcephaly (76%; 95% CI 69-82%) and brain abnormalities (78%; 95% CI 69-86%) were confirmed postnatally. Among 190 fetuses without congenital Zika syndrome findings on prenatal ultrasound examination, 17% (95% CI 12-24%) had congenital Zika syndrome abnormalities identified postnatally. Structural congenital Zika syndrome abnormalities were identified postnatally in approximately equal proportions among dyads with and without Zika virus RNA detected in an amniotic fluid specimen (68% and 67%; 95% CI 52-82% and 95% CI 38-88%). In six pregnancies, Zika virus RNA was detected in amniotic fluid but not in a subsequent amniocentesis specimen.

CONCLUSION

Prenatal ultrasound examination frequently detects structural findings associated with Zika virus infection; however, not all abnormalities are detected, and some may represent transient findings. As with other congenital infections, prenatal detection may vary with timing of infection, timing of ultrasound examination, technical expertise, and severity of abnormalities. The detection of Zika virus RNA in amniotic fluid in the included studies did not predict the risk for congenital Zika syndrome abnormalities in these cases, and clearance of Zika virus RNA from amniotic fluid appears possible after maternal infection. Diagnostic testing for Zika virus infection remains a shared decision between patients and clinicians, and more data are needed to define clinical predictors that will inform these decisions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42018080959.

Zika virus detection in amniotic fluid and Zika-associated birth defects

BACKGROUND

Zika virus infection during pregnancy can cause serious birth defects, which include brain and eye abnormalities. The clinical importance of detection of Zika virus RNA in amniotic fluid is unknown.

OBJECTIVE

The purpose of this study was to describe patterns of Zika virus RNA testing of amniotic fluid relative to other clinical specimens and to examine the association between Zika virus detection in amniotic fluid and Zika-associated birth defects. Our null hypothesis was that Zika virus detection in amniotic fluid was not associated with Zika-associated birth defects.

STUDY DESIGN

We conducted a retrospective cohort analysis of women with amniotic fluid specimens submitted to Colombia's National Institute of Health as part of national Zika virus surveillance from January 2016 to January 2017. Specimens (maternal serum, amniotic fluid, cord blood, umbilical cord tissue, and placental tissue) were tested for the presence of Zika virus RNA with the use of a singleplex or multiplex real-time reverse transcriptase-polymerase chain reaction assay. Birth defect information was abstracted from maternal prenatal and infant birth records and reviewed by expert clinicians. Chi-square and Fisher's exact tests were used to compare the frequency of Zika-associated birth defects (defined as brain abnormalities [with or without microcephaly, but excluding neural tube defects and their associated findings] or eye abnormalities) by frequency of detection of Zika virus RNA in amniotic fluid.

RESULTS

Our analysis included 128 women with amniotic fluid specimens. Seventy-five women (58%) had prenatally collected amniotic fluid; 42 women (33%) had amniotic fluid collected at delivery, and 11 women (9%) had missing collection dates. Ninety-one women had both amniotic fluid and other clinical specimens submitted for testing, which allowed for comparison across specimen types. Of those 91 women, 68 had evidence of Zika virus infection based on detection of Zika virus RNA in ≥1 specimen. Testing of amniotic fluid that was collected prenatally or at delivery identified 39 of these Zika virus infections (57%; 15 [22%] infections were identified only in amniotic fluid), and 29 infections (43%) were identified in other specimen types and not amniotic fluid. Among women who were included in the analysis, 89 had pregnancy outcome information available, which allowed for the assessment of the presence of Zika-associated birth defects. Zika-associated birth defects were significantly (P<.05) more common among pregnancies with Zika virus RNA detected in amniotic fluid specimens collected prenatally (19/32 specimens; 59%) than for those with no laboratory evidence of Zika virus infection in any specimen (6/23 specimens; 26%), but the proportion was similar in pregnancies with only Zika virus RNA detected in specimens other than amniotic fluid (10/23 specimens; 43%). Although Zika-associated birth defects were more common among women with any Zika virus RNA detected in amniotic fluid specimens (ie, collected prenatally or at delivery; 21/43 specimens; 49%) than those with no laboratory evidence of Zika virus infection (6/23 specimens; 26%), this comparison did not reach statistical significance (P=.07).

CONCLUSION

Testing of amniotic fluid provided additional evidence for maternal diagnosis of Zika virus infection. Zika-associated birth defects were more common among women with Zika virus RNA that was detected in prenatal amniotic fluid specimens than women with no laboratory evidence of Zika virus infection, but similar to women with Zika virus RNA detected in other, nonamniotic fluid specimen types.

Researching Zika in pregnancy: lessons for global preparedness

Our understanding of congenital infections is based on prospective studies of women infected during pregnancy. The EU has funded three consortia to study Zika virus, each including a prospective study of pregnant women. Another multi-centre study has been funded by the US National Institutes of Health. This Personal View describes the study designs required to research Zika virus, and questions whether funding academics in the EU and USA to work with collaborators in outbreak areas is an effective strategy. 3 years after the 2015-16 Zika virus outbreaks, these collaborations have taught us little about vertical transmission of the virus. In the time taken to approve funding, agree contracts, secure ethics approval, and equip laboratories, Zika virus had largely disappeared. By contrast, prospective studies based on local surveillance and standard-of-care protocols have already provided valuable data. Threats to fetal and child health pose new challenges for global preparedness requiring support for the design and implementation of locally appropriate protocols. These protocols can answer the key questions earlier than externally designed studies and at lower cost. Local protocols can also provide a framework for recruitment of unexposed controls that are required to study less specific outcomes. Other priorities include accelerated development of non-invasive tests, and longer-term storage of neonatal and antenatal samples to facilitate retrospective reconstruction of cohort studies.

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.

Pregnancy outcomes after maternal Zika virus infection in a non-endemic region: prospective cohort study

OBJECTIVES

The aim was to describe pregnancy outcomes after Zika virus (ZIKV) infection in a non-endemic region.

METHODS

According to the Spanish protocol issued after the ZIKV outbreak in Brazil in 2015, all pregnant women who had travelled to high-burden countries were screened for ZIKV. Serological and molecular tests were used to identify ZIKV-infected pregnant women. They were classified as confirmed ZIKV infection when reverse transcription (RT) PCR tested positive, or probable ZIKV infection when ZIKV immunoglobulin M and/or immunoglobulin G and ZIKV plaque reduction neutralization tests were positive. Women found positive using molecular or serological tests were prospectively followed-up with ultrasound scans and neurosonograms on a monthly basis until delivery; magnetic resonance imaging and amniotic fluid testing were performed after signed informed consent. Samples of placenta, and fetal and neonatal tissues were obtained.

RESULTS

Seventy-two pregnant women tested positive for ZIKV infection: ten were confirmed by RT-PCR, and 62 were probable cases based on serological tests. The prevalence of adverse perinatal outcomes was 33.3% (three out of nine, 95% CI 12.1-64.6%): two cases of congenital ZIKV syndrome (CZS) and one miscarriage, all born to women infected in the first trimester of gestation. All ZIKV-confirmed women had persistent viraemias beyond 2 weeks (median 61.50 days; IQR 35.50-80.75). Amniotic fluid testing was only positive in the two fetuses with anomalies.

CONCLUSION

The prevalence of perinatal adverse outcomes for women with ZIKV-confirmed infection was 33.3%. Amniocentesis for ZIKV RT-PCR is recommended when fetal abnormalities are found. Intensive prenatal and postnatal follow-up of ZIKV-infected pregnancies is advised in confirmed cases.

Maternal-fetal transmission and adverse perinatal outcomes in pregnant women infected with Zika virus: prospective cohort study in French Guiana

OBJECTIVES

To estimate the rates of maternal-fetal transmission of Zika virus, adverse fetal/neonatal outcomes, and subsequent rates of asymptomatic/symptomatic congenital Zika virus infections up to the first week of life.

DESIGN

Cohort study with prospective data collection and subsequent review of fetal/neonatal outcomes.

SETTINGS

Referral centre for prenatal diagnosis of the French Guiana Western Hospital.

PARTICIPANTS

Pregnant women at any stage of pregnancy with a laboratory confirmed symptomatic or asymptomatic Zika virus infection during the epidemic period in western French Guiana. The cohort enrolled 300 participants and prospectively followed their 305 fetuses/newborns.

MAIN OUTCOME MEASURES

Rate of maternal-fetal transmission of Zika virus (amniotic fluid, fetal and neonatal blood, urine, cerebrospinal fluid, and placentas); clinical, biological, and radiological outcomes (blindly reviewed); and adverse outcomes defined as moderate signs potentially related to congenital Zika syndrome (CZS), severe complications compatible with CZS, or fetal loss. Associations between a laboratory confirmed congenital Zika virus infection and adverse fetal/neonatal outcomes were evaluated.

RESULTS

Maternal-fetal transmission was documented in 26% (76/291) of fetuses/newborns with complete data. Among the Zika virus positive fetuses/newborns, 45% (34/76) presented with no signs/complications at birth, 20% (15/76) with moderate signs potentially related to CZS, 21% (16/76) with severe complications compatible with CZS, and 14% (11/76) with fetal loss. Compared with the Zika virus positive fetuses/neonates, those that were identified as negative for Zika virus (215/291) were less likely to present with severe complications (5%; 10/215) or fetal loss (0.5%; 1/215; relative risk 6.9, 95% confidence interval 3.6 to 13.3). Association between a positive Zika virus test and any adverse fetal/neonatal outcome was also significant (relative risk 4.4, 2.9 to 6.6). The population attributable fraction estimates that a confirmed congenital Zika virus infection contributes to 47% of adverse outcomes and 61% of severe adverse outcomes observed.

CONCLUSION

In cases of a known maternal Zika virus infection, approximately a quarter of fetuses will become congenitally infected, of which a third will have severe complications at birth or fetal loss. The burden of CZS might be lower than initially described in South America and may not differ from other congenital infections.

What we know and what we don't know about perinatal Zika virus infection: a systematic review

INTRODUCTION

Zika virus (ZIKV) infection has caused the most challenging worldwide infectious epidemic outbreak in recent months. ZIKV causes microcephaly and other congenital malformations. There is a need to perform updated systematic reviews on ZIKV infection periodically because this epidemic is bringing up new evidence with extraordinary speed. Areas covered: Evidence related to ZIKV infection in the gestational, perinatal, and early infant periods covering epidemiology, virology, pathogenesis, risk factors, time of infection during pregnancy, newborn symptoms, treatment, and vaccines. To this end, a search was performed using terms ['Zika'] AND ['Perinatal Infection'] OR ['Congenital Infection'] in the PubMed® international electronic database. Out of a total of 1,538 articles published until 30 November 2017, we finally assessed 106 articles articles that were relevant to the research areas included in this study. Expert commentary: ZIKV is a new teratogenic/neurotropic virus affecting fetuses. Many challenges are still far from being solved regarding the epidemiology, case definition, clinical and laboratory diagnosis, and preventive measures. An approach using 'omics' and new biomarkers for diagnosis, and a ZIKV-vaccine for treatment, might finally give us the tools to solve these challenges.