Other viruses


Oct, 2019

Experimental infection of pregnant female sheep with Zika Virus during early gestation


Authors: Schwarz ER, Pozor MA, Pu R, et al.

Published in: Viruses. 2019;11(9)

Abstract Zika virus (ZIKV) is a vertically and sexually transmissible virus resulting in severe congenital malformation. The goal of this study was to develop an ovine model of ZIKV infection. Between 28–35 days gestation (DG), four pregnant animals were infected with two doses of 6 × 106 PFU of ZIKV; four control animals received PBS. Animals were evaluated for 45 days (D) post-infection (PI) and necropsies were performed. Viral RNA was detected in infected ewe peripheral blood mononuclear cells (PBMC) during the first week PI; however, all fluids and tissues were negative upon culture. Anti-ZIKV IgM (1:400) and neutralizing antibodies were detected in all infected animals. Clinical disease, virus, or ZIKV antibodies were not detected in control ewes. After two weeks PI, fetal loss occurred in two infected animals, and at necropsy, three infected animals had placental petechiation and ecchymosis and one had hydramnion. Fetal morphometrics revealed smaller cranial circumference to crown-rump length ratios (p < 0.001) and relative brain weights (p = 0.038) in fetuses of infected animals compared with control fetuses. Immunophenotyping indicated an increase in B cells (p = 0.012) in infected sheep. Additionally, in vitro experiments using both adult and fetal cell lines demonstrated that ovine cells are highly permissive to ZIKV infection. In conclusion, ZIKV infection of pregnant sheep results in a change in fetal growth and gestational outcomes.



Oct, 2019

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


Authors: Sulleiro E, Rando A, Alejo I, et al.

Published in: Clin Microbiol Infect. 2019;25(5):633.e5-633.e9

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.

Conclusions 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.


Oct, 2019

Screening for Zika virus infection in 1057 potentially exposed pregnant women, Catalonia (northeastern Spain)


Authors: Sulleiro E, Rando A, Alejo I, et al.

Published in: Travel Med Infect Dis. 2019;29:69-71

No abstract available


Oct, 2019

Development of secondary microcephaly after delivery: possible consequence of mother-baby transmission of Zika Virus in breast milk


Authors: Siqueira Mello A, Pascalicchio Bertozzi APA, Rodrigues MMD, et al.

Published in: Am J Case Rep. 2019 May 21;20:723-725

Background The Zika virus is an arbovirus that has as main source of transmission the bite of infected insects of the genus Aedes and has been associated with cases of congenital malformation and microcephaly in neonates. However, other sources of transmission have been identified since the emergence of this virus in the world population, such as vertical transmission by semen and possibly other body fluids such as vaginal secretion and breast milk.
Case Report An infant, born to a mother whose previous delivery was a baby with severe microcephaly, was normal and was negative for Zika virus at birth but developed secondary microcephaly 1 month later, that persisted. The baby was exclusively breast-fed and Zika virus was present in the mother’s milk.
Conclusions We report the detection of Zika virus exclusively in the breast milk of a woman after her second delivery of an infant, who later developed microcephaly. This case is consistent with possible vertical transmission.



Oct, 2019

Detection of Zika virus in paired urine and amniotic fluid samples from symptomatic and asymptomatic women and their babies during a disease outbreak: association with neurological symptoms in newborns


Authors: Vedovello D, Witkin SS, Silva ACB, et al.

Published in: J Neurovirol 2019 Sep 9. doi: 10.1007/s13365-019-00797-0

Abstract Paired maternal and newborn urine and amniotic fluid from 138 subjects collected during a Zika virus (ZIKV) outbreak was analyzed for ZIKV by gene amplification (RT-qPCR), and the findings were correlated with clinical symptoms and neurological anomalies in the babies. ZIKV was detected in 1 of 9 symptomatic women (11.1%) and in 19 of 129 asymptomatic women (14.7%). Neurological manifestations were present in 19 babies (13.7%), 10 of 20 (50%) positive and 9 of 119 (7.6%) negative (p < 0.001) for ZIKV. Twelve (8.6%) urines collected during gestation were ZIKV-positive; only 2 remained positive for ZIKV postpartum. Six (4.1%) newborn urines collected within 1 day of delivery were ZIKV-positive cases. In 3 of these cases, ZIKV was detected in mother’s urine pre- and postpartum and in both mother’s urine and babies’ urine. Four of the amniotic fluid samples (2.9%) were ZIKV-positive. Among ZIKV-negative babies with neurological sequel, 87.5% were female; in contrast, 72.7% ZIKV-positive babies with neurological abnormalities were male (p = 0.019). We conclude that during a ZIKV outbreak, clinical symptoms and ZIKV detection in biological fluids are poor predictors of infection and adverse neurologic sequel in newborns.



Sep, 2019

The challenge of the laboratory diagnosis in a confirmed congenital Zika virus syndrome in utero: a case report


Authors: Sulleiro E, Frick MA, Rodó C, et al.

Published in: Medicine (Baltimore). 2019;98(20):e15532

Introduction Zika virus (ZIKV) has caused one of the most challenging global infectious epidemics in recent years because of its causal association with severe microcephaly and other congenital malformations. The diagnosis of viral infections usually relies on the detection of virus proteins or genetic material in clinical samples as well as on the infected host immune responses. Serial serologic testing is required for the diagnosis of congenital infection when diagnostic molecular biology is not possible.

Patient concerns A 2-year-old girl, born to a mother with confirmed ZIKV infection during pregnancy, with a confirmed ZIKV infection in utero, showed at birth a severe microcephaly and clinical characteristics of fetal brain disruption sequence compatible with a congenital ZIKV syndrome (CZS).

Diagnosis ZIKV-RNA and ZIKV-IgM serological response performed at birth and during the follow-up time tested always negative. Serial serologic ZIKV-IgG tests were performed to assess the laboratory ZIKV diagnosis, ZIKV-IgG seroreversion was observed at 21 months of age. ZIKV diagnosis of this baby had to be relied on her clinical and radiological characteristics that were compatible with a CZS.

Interventions The patient was followed-up as per protocol at approximately 1, 4, 9, 12, 18-21, and 24 months of age. Neurological, radiological, audiological, and ophthalmological assessment were performed during this period of time. Prompt rehabilitation was initiated to prevent potential adverse long-term neurological outcomes.

Outcomes The growth of this girl showed a great restriction at 24 months of age with a weight of 8.5 kg (-2.5 z-score) and a head circumference of 40.5 cm (-4.8 z-score). She also had a great neurodevelopmental delay at the time of this report.

Conclusions We presume that as a consequence of prenatal ZIKV infection, the fetal brain and other organs are damaged before birth through direct injury. Following this, active infection ends during intrauterine life, and as a consequence the immune system of the infant is unable to build up a consistent immune response thereafter. Further understanding of the mechanisms taking part in the pathogenesis of ZIKV congenital infection is needed. This finding might change our paradigm regarding serological response in the ZIKV congenital infection.



Sep, 2019

Past and future spread of the arbovirus vectors Aedes aegypti and Aedes albopictus


Authors: Kraemer MUG, Reiner RC Jr, Brady OJ, et al.

Published in: Nat Microbiol. 2019;4:900

Abstract The global population at risk from mosquito-borne diseases—including dengue, yellow fever, chikungunya and Zika—is expanding in concert with changes in the distribution of two key vectors: Aedes aegypti and Aedes albopictus. The distribution of these species is largely driven by both human movement and the presence of suitable climate. Using statistical mapping techniques, we show that human movement patterns explain the spread of both species in Europe and the United States following their introduction. We find that the spread of Ae. aegypti is characterized by long distance importations, while Ae. albopictus has expanded more along the fringes of its distribution. We describe these processes and predict the future distributions of both species in response to accelerating urbanization, connectivity and climate change. Global surveillance and control efforts that aim to mitigate the spread of chikungunya, dengue, yellow fever and Zika viruses must consider the so far unabated spread of these mosquitos. Our maps and predictions offer an opportunity to strategically target surveillance and control programmes and thereby augment efforts to reduce arbovirus burden in human populations globally.



Sep, 2019

Understanding the relation between Zika virus infection during pregnancy and adverse fetal, infant and child outcomes: a protocol for a systematic review and individual participant data meta-analysis of longitudinal studies of pregnant women and their infants and children


Authors: Wilder-Smith A, Wei Y, Araújo TVB et al;Zika Virus Individual Participant Data Consortium

Published in: BMJ Open. 2019;9(6):e026092. doi: 10.1136/bmjopen-2018-026092.

Introduction Zika virus (ZIKV) infection during pregnancy is a known cause of microcephaly and other congenital and developmental anomalies. In the absence of a ZIKV vaccine or prophylactics, principal investigators (PIs) and international leaders in ZIKV research have formed the ZIKV Individual Participant Data (IPD) Consortium to identify, collect and synthesise IPD from longitudinal studies of pregnant women that measure ZIKV infection during pregnancy and fetal, infant or child outcomes.

Methods and analysis We will identify eligible studies through the ZIKV IPD Consortium membership and a systematic review and invite study PIs to participate in the IPD meta-analysis (IPD-MA). We will use the combined dataset to estimate the relative and absolute risk of congenital Zika syndrome (CZS), including microcephaly and late symptomatic congenital infections; identify and explore sources of heterogeneity in those estimates and develop and validate a risk prediction model to identify the pregnancies at the highest risk of CZS or adverse developmental outcomes. The variable accuracy of diagnostic assays and differences in exposure and outcome definitions means that included studies will have a higher level of systematic variability, a component of measurement error, than an IPD-MA of studies of an established pathogen. We will use expert testimony, existing internal and external diagnostic accuracy validation studies and laboratory external quality assessments to inform the distribution of measurement error in our models. We will apply both Bayesian and frequentist methods to directly account for these and other sources of uncertainty.

Ethics and dissemination The IPD-MA was deemed exempt from ethical review. We will convene a group of patient advocates to evaluate the ethical implications and utility of the risk stratification tool. Findings from these analyses will be shared via national and international conferences and through publication in open access, peer-reviewed journals.



May, 2019

Islands as Hotspots for Emerging Mosquito-Borne Viruses: A One-Health Perspective


Authors: Mavian C, Dulcey M, Munoz O, Salemi M, Vittor AY, Capua I.

Published in: Viruses. 2019; 11(1):11

Abstract During the past ten years, an increasing number of arbovirus outbreaks have affected tropical islands worldwide. We examined the available literature in peer-reviewed journals, from the second half of the 20th century until 2018, with the aim of gathering an overall picture of the emergence of arboviruses in these islands. In addition, we included information on environmental and social drivers specific to island setting that can facilitate the emergence of outbreaks. Within the context of the One Health approach, our review highlights how the emergence of arboviruses in tropical islands is linked to the complex interplay between their unique ecological settings and to the recent changes in local and global sociodemographic patterns. We also advocate for greater coordination between stakeholders in developing novel prevention and mitigation approaches for an intractable problem.




Apr, 2019

Immunoglobulin-like Domain of HsFcμR as a Capture Molecule for Detection of Crimean-Congo Hemorrhagic Fever Virus- and Zika Virus-Specific IgM Antibodies


Authors: Rackow A, Ehmen C, von Possel R, et al.

Published in: Clin Chem. 2019;65(3):451-461.

Background The cellular surface molecule HsTOSO/FAIM3/HsFcμR has been identified as an IgM-specific Fc receptor expressed on lymphocytes. Here, we show that its extracellular immunoglobulin-like domain (HsFcμR-Igl) specifically binds to IgM/antigen immune complexes (ICs) and exploit this property for the development of novel detection systems for IgM antibodies directed against Crimean-Congo hemorrhagic fever virus (CCHFV) and Zika virus (ZIKV).

Methods His-tagged HsFcμR-Igl was expressed in Escherichia coli and purified by affinity chromatography, oxidative refolding, and size-exclusion chromatography. Specific binding of HsFcμR-Igl to IgM/antigen ICs was confirmed, and 2 prototypic ELISAs for the detection of anti-CCHFV and anti-ZIKV IgM antibodies were developed. Thereby, patient sera and virus-specific recombinant antigens directly labeled with horseradish peroxidase (HRP) were coincubated on HsFcμR-Igl-coated ELISA plates. Bound ICs were quantified by measuring turnover of a chromogenic HRP substrate.

Results Assay validation was performed using paired serum samples from 15 Kosovar patients with a PCR-confirmed CCHFV infection and 28 Brazilian patients with a PCR-confirmed ZIKV infection, along with a panel of a priori CCHFV/ZIKV-IgM-negative serum samples. Both ELISAs were highly reproducible. Sensitivity and specificity were comparable with or even exceeded in-house gold standard testing and commercial kits. Furthermore, latex beads coated with HsFcμR-Igl aggregated upon coincubation with an IgM-positive serum and HRP-labeled antigen but not with either component alone, revealing a potential for use of HsFcμR-Igl as a capture molecule in aggregation-based rapid tests.

Conclusions Recombinant HsFcμR-Igl is a versatile capture molecule for IgM/antigen ICs of human and animal origin and can be applied for the development of both plate- and bead-based serological tests.