Researchers suspect Zika infection causes the condition, called microcephaly, but are still trying to prove it. Reports have documented traces of the virus in the brains of babies with microcephaly who’d died soon after birth, and in fetal brain tissue after abortion.
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“So a very important question that emerges from our work is whether the Zika virus specifically targets the neural progenitor mostly responsible for generating the cortex”, Min said.
“We don’t feel that there’s a public health threat because Zika virus is mostly spread by the bite of the mosquito and the mosquitoes that carry Zika virus are not present in Contra Costa County”, she said. “We did not directly conclude that Zika infection causes microcephaly”, said Professor Tang, a virologist, whose study was published Friday in the USA journal Cell Stem Cell.
A recent study in Cell Press found that the Zika virus infects a type of neural stem cell that affects the brain’s cerebral cortex.
The Zika virus is commonly spread by mosquitoes, though it can also be sexually transmitted. The stems cells can result in cell death or disrupt cell growth, the study found. According to the CDC, babies with microcephaly often have smaller head sizes and brains that might not have developed properly. But the missing relationship is how the infection can depress or stagnate brain development in utero.
Colombians first started testing positive for Zika in October, months after the current outbreak took hold in Brazil.
Because there is no vaccine for Zika virus, the CDC encourages people traveling to Zika-affected areas to wear EPA-registered insect repellant and practice safe sex with their partners. In as few as 3 days following exposure to the virus, 90% of the cortical neural progenitor cells in a lab dish had become infected. However, these findings do not show definitive proof about the connection between Zika virus and microcephaly.
Since the outbreak, researchers have been scrambling to come up with a way to stop it and on Friday, those at Johns Hopkins announced a breakthrough in understanding how the virus attacks the nervous system.
There have been rising concerns globally about the association of Zika virus and severe birth defects like microcephaly.
Dr. Catherine Spong, director of the National Institute of Child Health and Human Development, warned that the sample size is small, and that Zika did not necessarily cause all these problems.
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Nielsen says their study and others like it could help eliminate theories that the pesticides used against mosquitoes (and not the virus itself) are the culprit.
