“We only studied mice and human tissues, so we can’t say for sure what happens when pregnant women are infected with these viruses,” said Jonathan Miner, MD, PhD, an assistant professor of medicine and the study’s senior author. “But our findings suggest that it is possible that viruses related to Zika, such as West Nile, pose the same risk to developing fetuses that Zika does.”

The study is published Jan. 31 in Science Translational Medicine.

Zika virus garnered worldwide attention beginning in 2015, when reports of an outbreak surfaced in Brazil. Alarm heightened when researchers linked Zika infection in pregnant women with the risk of bearing babies born with microcephaly, or abnormally small heads.

Read more at Washington University School of Medicine

Image: West Nile virus (green) grows in human placenta, where the cells are marked red with blue nuclei. A study has found that viruses related to Zika, such as West Nile, can cross the placenta in mice and cause fetal brain damage and death. (Credit: Nitin Arora)