Zika infection can damage fetuses even if pregnant women show no symptoms

The Zika virus can harm developing fetuses even if a pregnant woman’s infection is so mild she shows no symptoms, scientists from Colombia and the Centers for Disease Control and Prevention reported Wednesday. Four women from Colombia who had asymptomatic Zika infections during pregnancy gave birth to babies who had microcephaly — an abnormally small head. The newborns were confirmed to have the Zika virus in their systems, the researchers reported in an article published in the New England Journal of Medicine. “We do think the majority of Zika virus infections are asymptomatic. And this does provide some evidence that asymptomatic infections during pregnancy do pose a risk to the fetus,” said Margaret Honein, an epidemiologist and a senior author of the paper. “I think our level of concern for pregnant women is very high, for both symptomatic and asymptomatic infections with Zika virus,” Honein said. It is estimated that 4 out of 5...