It’s still uncertain whether Zika is to blame for a scary increase in infants with small brains, but now researchers say they think they know how it could happen.
Scientists say they infected cells in a lab with the Zika virus and found it selectively harmed a kind of cells in the brain’s cortex, causing them to die, but didn’t harm other cell types.
The work “offers among the strongest evidence yet of how Zika is harming fetuses,” according to the Washington Post. If the virus kills cortex cells it would explain why the infants are born with small brains.
The Zika virus is spread by mosquitoes and began ricocheting around South America last year. A substantial uptick in the number of cases of microcephaly in Brazil suggested there was a link to the virus, and Colombian researchers say they are finding birth defects in that country, too.
The World Health Organization has sent a team to Colombia to investigate the link between Zika and microcephaly in roughly 5,000 pregnant women, according to the New York Times.