In Brazil, Zika has been linked to babies born with unusually small heads, a birth defect called microcephaly that can signal underlying brain damage. A recent report found a stillborn foetus with devastating loss of brain tissue, but also another defect that by itself can be life-threatening: severe swelling and fluid build-up in other parts of the body.
Researchers found Zika virus in foetal tissue even though the mother reported no symptoms. The findings don't prove Zika caused the defects, but the researchers said closer investigation of stillbirths in Zika-affected areas may be warranted.
The report was published in the journal PLOS Neglected Tropical Diseases.
Disease detectives should take a closer look at stillbirths in Zika-affected areas, concluded the team from Yale University and the Hospital Geral Roberto Santos in Salvador, Brazil.
Zika is spreading rapidly through Latin America and has raised global concern.
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Whether the mosquito-borne Zika really causes microcephaly isn't yet proven. But in a handful of previously published cases, researchers have found both the virus and serious brain abnormalities after foetal or newborn death.
The new report could alert doctors to watch for other congenital problems during prenatal ultrasound exams of women potentially at risk. The fluid problem is called hydrops fetalis.
Systemic infection of the foetus
If a doctor spotted hydrops alone, "you might not immediately attribute it to Zika virus because what has been described are brain abnormalities", said Dr Sallie Permar of the Duke Human Vaccine Institute, an expert on maternal-foetal viral infections who wasn't involved with the Brazil case.
The case raises the possibility "that this could be a systemic infection of the foetus, that not only the brain development could be affected", Permar added.
With the stillbirth, an ultrasound showed no sign of trouble in the 14th week of pregnancy, but at 18 weeks, another ultrasound found the foetus weighed too little, the Yale-Brazil team reported. Doctors could detect a range of defects by week 30, including microcephaly and the fluid problem. Two weeks later, the foetus died. Subsequent testing detected the Zika virus' genetic material in brain tissue and amniotic fluid.
U.S. health officials say pregnant women or those considering becoming pregnant shouldn't travel to Zika-affected areas. If pregnant women already travelled to at-risk areas, they can undergo certain tests to try to detect if they were infected, as well as ultrasound exams to track foetal health.
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Image: Newborn in a basket from iStock