Zika virus 'may be linked to effects other than in central nervous system'

Zika infection may have life-threatening effects on unborn babies that are not just confined to the brain, a study has found.

In January a young Brazilian woman had a stillborn baby girl with the characteristic small head associated with the virus as well as signs of severe neurological damage.

But doctors also identified symptoms of a potentially fatal foetal disorder called hydrops fetalis that causes tissues to fill with fluid.

Tests confirmed the presence of Zika in the foetus, delivered by induced labour in the 32nd week of pregnancy.

Only one such case has been reported so far, but the details are worrying enough to prompt a new Zika warning from scientists.

Dr Albnert Ko, from the Yale School of Public Health in the US, who led the investigation team, said: "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.

"Additional work is needed to understand if this is an isolated finding and to confirm whether Zika virus can actually cause hydrops fetalis."

Zika infection has already been linked to microcephaly, a condition marked by babies being born with abnormally small heads and brain damage.

Despite a lack of causal evidence, the strength of the association has led the World Health Organisation to declare Zika an international public health emergency.

The new case is reported in the journal Public Library of Science Neglected Tropical Diseases.

It involved a 20-year-old woman from the city of Salvador whose first three months of pregnancy had seemed normal.

That changed abruptly in the 18th week when an ultrasound scan revealed that the unborn baby's weight was well below what it should have been.

The woman had not reported any of the symptoms commonly associated with Zika, such as a rash, fever or body aches.

Nor had she exhibited symptoms of other tropical mosquito-borne diseases such as dengue or chikungunya.

By the 30th week of pregnancy it became clear that the foetus had developed a range of birth defects, including severe microcephaly.

Two weeks later a decision to carry out an induced birth was taken after the baby's death in the womb was confirmed.

Doctors found evidence of hydranencephaly, an almost complete loss of brain tissue, which has previously been linked to Zika infection.

But the discovery of hydrops fetalis was unexpected.

The Zika scare began in Brazil last November when an outbreak of infections by the virus coincided with a large increase in numbers of babies born with microcephaly.

Between November 2015 and February 13 a total of 5,280 cases of babies born with microcephaly and/or central nervous system malformation were reported in Brazil, including 108 deaths.

Zika has spread rapidly across more than 20 countries in the Americas, and US officials are investigating 14 possible cases of sexual transmission of the virus. It is normally transmitted through bites by the Aedes mosquito.