A Brazilian woman infected with the Zika virus has given birth to a stillborn baby who had signs of severe tissue swelling as well as central nervous system defects that caused near-complete loss of brain tissue, according to a new report.
It is the first report to indicate a possible association of congenital Zika virus and damage to tissues outside the central nervous system, researchers said.
Researchers 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).
They 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 findings raise concerns that the virus may cause severe damage to foetuses leading to stillbirths and may be associated with effects other than those seen in the central nervous system," said Dr Albert Ko, from the Yale School of Public Health (YSPH).
"Additional work is needed to understand if this is an isolated finding and to confirm whether Zika virus can actually cause hydrops fetalis," said Ko, who described the case with Dr Antonio Raimundo de Almeida from the Hospital Geral Roberto Santos in Brazil.
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 of 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.
The study was published in the journal PLOS Neglected Tropical Diseases.
