Study Links Zika Virus To Microcephaly

In a breakthrough, researchers suggest the virus attacks critical fetal cells

(Illustration: Tara Jacoby)
Mar 04, 2016 at 2:46 PM ET

Despite the current state of emergency in Brazil, scientists have yet to definitively prove that the Zika virus causes microcephaly, a condition in which babies are born with abnormally small heads and undeveloped brains. But a groundbreaking new study strengthens the link between the two and suggests a mechanism for how the mosquito-borne virus could attack fetal cells.

The study, conducted by a team of U.S. researchers and published in the journal Cell Stem Cell, found that the virus targets cortical neural progenitor, which are cells that are critical to the development of the cerebral cortex, the outer layer of the brain. In petri dishes, several different kinds of stem cells were exposed to the virus. Within days, 90 percent of cortical neural progenitor cells were infected and found to be “havens for viral reproduction,” as a press release puts it.

“This is a first step, and there’s a lot more that needs to be done,” said Hongjun Song of the Johns Hopkins University School of Medicine. “What we show is that the Zika virus infects neuronal cells in dish that are counterparts to those that form the cortex during human brain development.”

Researchers have previously linked a rise in microcephaly cases, particularly in Brazil, with the Zika outbreak. They’ve also found evidence of the virus in the brains of infants with microcephaly. But this research is the first to document exactly how the virus might impact fetal brain development. Of course, it’s worth noting that the research was conducted on lab-grown cells. As Song told The Baltimore Sun, “It was in a dish, not in a fetus. But it fits.”