Publications

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.

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.

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

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

No abstract available

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.

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.