The damage the Zika virus can do to a developing fetus appears to be even greater than has been previously understood, the World Health Organization said Friday.
The birth defect most commonly associated with Zika has been microcephaly, in which babies are born with abnormally small heads. Citing unpublished findings from Colombia and Panama, however, WHO scientists warned in an editorial that the cardiac, digestive, and genitourinary systems of affected infants can also sustain damage.
Some babies born to mothers infected with Zika have also been found to have neurological problems.
The Geneva-based global health agency made a plea to doctors and scientists studying infants born to women who were infected in pregnancy to share more data on their findings, so that that the WHO can better define what is coming to be known as congenital Zika syndrome.
“Most data related to congenital manifestations of Zika infection remain unpublished,” WHO scientists said in the editorial, published in the Bulletin of the World Health Organization.
“Further analysis of data from cohorts of pregnant women with Zika virus infection are needed to understand all outcomes of Zika virus infection in pregnancy,” they added.
For awhile now, experts studying the babies born to women who were infected with Zika in pregnancy have warned that microcephaly appears to be the tip of a much larger iceberg.
Some studies have suggested that as few as 1 in 100 women infected in pregnancy might go on to have a child with microcephaly — though one of those papers said the figure might be as high as 13 percent.
But scientists following a group of pregnant women in Brazil who were infected reported that 29 percent of the babies born had birth defects ranging from microcephaly to brain damage to eye problems. Other studies have reported hearing problems in babies born to women infected in pregnancy.
The definition of congenital Zika syndrome is expected to expand over time, the WHO scientists said, as more information is received and as follow-up studies of affected children reveal whether they experience additional developmental problems.