Zika virus linked with stillbirths, loss of brain tissue and rare birth defects

New research has uncovered a potential link between the Zika virus and stillbirths.

The study, published in the journal PLOS Neglected Tropical Diseases, and led by Albert Ko, MD of the Yale School of Public Health and Dr Antônio Raimundo in Salvador, Brazil, investigated the case of a woman infected with Zika and who gave birth to a stillborn baby in January 2016.

An examination of the foetus revealed that the cerebral hemispheres of its brain were missing. Researchers identified central nervous system defects, but also, for the first time, tissues swelling outside the nervous system that explained this anomaly.

Tissues swelling and central nervous system

The 20-year-old mother's pregnancy was normal up to the 18<sup>th week, when an ultrasound revealed that her baby's weight was particularly low. Labour was induced on the 32<sup>nd week after it appeared the foetus' development was not going as planned, and that he suffered from a range of defects.

Later tests revealed traces of the Zika virus in the baby's body, transmitted by his mother. Before then, she was not aware that she had contracted the disease, as she didn't have any of the symptoms (fever, rash or body aches). This situation is not uncommon, as about 80% of people carrying the disease are asymptomatic, making Zika much harder to contain.

Multiple foetal defects

Scientists now believe that Zika could not only lead to conditions of microcephaly (where babies are born with abnormally small heads) but that it could also be associated to a range of birth defects, like hydrops fetalis (abnormal accumulation of fluid in fetal compartments) and hydranencephaly (almost complete loss of brain tissue), as well as stillbirths.

However, scientists remain cautious. "This case raises concern that Zika be associated with effects other than those seen in the central nervous system. It indicates an association, and suggest that the virus causes stillbirths, but it does not rigorously confirm causality", Dr Albert Ko told IBTimes UK.

More research is needed to understand if this case is an isolated finding. In the city of Salvador, more studies on newborns identified during surveillance are currently carried out for this purpose.

"We have more to learn about the spectrum of birth defects that the Zika virus may possibly cause. In addition, we will need to perform systematic studies, such as prospective investigations, that can establish the temporality of the association" commented Albert Ko.