A pregnant Brazilian woman infected with the Zika virus had a stillborn baby in January who had signs of severe tissue swelling as well as central nervous system defects that caused the cerebral hemispheres of the brain to be absent. It is the first report to indicate a possible association of congenital Zika virus and damage to tissues outside the central nervous system.
Researchers led by Dr Albert Ko of the Yale School of Public Health and Dr Antônio Raimundo de Almeida at the Hospital Geral Roberto Santos in Salvador, Brazil, describe the case.
Ko and colleagues said the case provides evidence that, in addition to microcephaly, (a condition marked by an abnormally small head in newborns and widely linked to the Zika outbreak in Brazil), congenital Zika infection may also be linked to hydrops fetalis (abnormal accumulation of fluid in foetal compartments), hydranencephaly (almost complete loss of brain tissue) and foetal demise (stillbirth).
The researchers said that it is not possible to extrapolate from a single case the overall risk for these outcomes faced by women who are exposed to the virus during pregnancy.
"These finding raise concerns that the virus may cause severe damage to fetuses leading to stillbirths and may be associated with effects other than those seen in the central nervous system," said Ko, chair of the department of epidemiology of microbial diseases, who has worked on the Zika outbreak in the coastal city of Salvador with Brazilian colleagues since shortly after the first cases of the mosquito-borne virus were reported there in early 2015. "Additional work is needed to understand if this is an isolated finding and to confirm whether Zika virus can actually cause hydrops fetalis."
The patient, a 20-year-old woman, was having a normal pregnancy during her first trimester. That changed abruptly during the course of the 18th week of pregnancy, when an ultrasound examination discovered that the foetus' weight was well below where it should have been at that point.
The woman did not report any of the symptoms commonly associated with Zika (rash, fever, or body aches) prior to or during the early stages or her pregnancy, the researchers said. She also did not exhibit symptoms of other mosquito-borne diseases, including dengue or chikungunya.
By the 30th week of the pregnancy, the foetus showed a range of birth defects. Labour was induced at the 32nd week. Researchers subsequently confirmed the presence of the Zika virus in the foetus. The strain of Zika that was found appears to be the same strain that is currently spreading elsewhere.
Since Zika appeared in Brazil, the virus has spread rapidly throughout much of Latin America and into the Caribbean. Several cases have also been confirmed in the US.
The researchers said that since it is likely that large numbers of pregnant women in Brazil and beyond will be exposed to the same Zika strain as the woman in the case study, further investigations are needed to determine the risk of stillbirth and the other adverse outcomes.
Ko worked on the study with colleagues from the Hospital Geral Roberto Santos in Salvador, the Universidade Federal da Bahia in Salvador, the Oswaldo Cruz Foundation in Salvador and the University of Texas Medical Branch in Galveston.
The rapid spread of Zika virus in the Americas and current outbreak of microcephaly in Brazil has raised attention to the possible deleterious effects that the virus may have on fetuses.
We report a case of a 20-year-old pregnant woman who was referred to our service after a large Zika virus outbreak in the city of Salvador, Brazil with an ultrasound examination that showed intrauterine growth retardation of the fetus at the 18th gestational week. Ultrasound examinations in the 2nd and 3rd trimesters demonstrated severe microcephaly, hydranencephaly, intracranial calcifications and destructive lesions of posterior fossa, in addition to hydrothorax, ascites and subcutaneous edema. An induced labor was performed at the 32nd gestational week due to fetal demise and delivered a female fetus. ZIKV-specific real-time polymerase chain reaction amplification products were obtained from extracts of cerebral cortex, medulla oblongata and cerebrospinal and amniotic fluid, while extracts of heart, lung, liver, vitreous body of the eye and placenta did not yield detectable products.
This case report provides evidence that in addition to microcephaly, there may be a link between Zika virus infection and hydrops fetalis and fetal demise. Given the recent spread of the virus, systematic investigation of spontaneous abortions and stillbirths may be warranted to evaluate the risk that ZIKV infection imparts on these outcomes.
The rapid spread of Zika virus in the Americas and outbreak of microcephaly in Brazil has raised attention to the possible deleterious effects that the virus may have on fetuses. We report a case of a 20-year-old pregnant woman from Salvador, Brazil whose fetus had developed hydrops fetalis, a condition where there is abnormal accumulation of fluid in the fetus, as well as severe central nervous system defects such as microcephaly and hydranencephaly. After fetal demise, ZIKV RNA was detected in central nervous system tissues and amniotic fluid. The case report provides evidence that in addition to microcephaly, there may be a link between Zika virus infection and hydrops fetalis and fetal demise. Given the recent spread of the virus, systematic investigation of spontaneous abortions and stillbirths may be warranted to evaluate the risk that ZIKV infection imparts on these outcomes.