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WASHINGTON — A stillbirth in Brazil is offering another clue to possible health effects of the Zika virus, this time beyond the developing brain.

In addition to a devastating loss of brain tissue, this fetus also had another abnormality — severe swelling and fluid build-up in other parts of the body — that by itself can be life-threatening, researchers reported Thursday.

Researchers found the Zika virus in the fetus even though the mother didn’t report any symptoms of infection, according to the case report 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 raised global concern after Brazil reported a surge in babies born with unusually small heads, a birth defect called microcephaly that can signal underlying brain damage.


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 fetal or newborn death.

Thursday’s report could alert doctors to watch for other congenital problems — like the fluid build-up cited in the study — during prenatal ultrasound exams of women potentially at risk. The fluid problem is called hydrops fetalis.

Are you at risk for contracting Zika virus? Your level of risk depends in part on your living conditions. Alex Hogan/STAT

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-fetal viral infections who wasn’t involved with the Brazil case.

The case raises the possibility “that this could be a systemic infection of the fetus, 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 fetus 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 fetus died. Subsequent testing detected the Zika virus’ genetic material in brain tissue and amniotic fluid.

US health officials say pregnant women or those considering becoming pregnant shouldn’t travel to Zika-affected areas. If pregnant women already traveled to at-risk areas, they can undergo certain tests to try to detect if they were infected, as well as ultrasound exams to track fetal health.

—Lauran Neergaard