On Friday scientists in the United States said they found the first concrete evidence of a link between the virus and the birth defect, which has so far been circumstantial.
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The department announced the case Friday but provided no other details.
Scientists from Johns Hopkins University, Emory University and Florida State University found that the virus likely targets a type of cell that actively divides in the human brain between the second and fourth month of gestation.
And knowing the mechanism of the virus could eventually allow researchers to design strategies to prevent the Zika virus from infecting different types of cells in the brain, the researchers explained.
As humans are typically infected by Zika virus carried by mosquitoes, the researchers also grew their Zika virus stock in mosquito cells for a few days before applying the virus onto the human cells used in all of their infection experiments.
“Zika virus has been found in the brains of aborted babies with small heads”, said Guo-Li Ming, Johns Hopkins University neurology professor.
“It is very telling that the cells that form the cortex are potentially susceptible to the virus”, Ming added.
“This research is the very first step in that, but it’s answering a critical question”. Of these women, 72 tested positive for Zika virus, and they were at various stages of pregnancy – anywhere from five to 38 weeks pregnant. These abnormalities included problems with growth, such as microcephaly (meaning an abnormally small head), problems with the placenta and lesions in the brain or spine.
Anecdotal evidence has suggested a link to microcephaly.
“We hope our results will help educate the public and government decision makers because they need to have more information on this virus, and we have to take it seriously”, Song said.
The infected stem cells then become the havens for the viral reproduction and thus result in complete cell death and or disruption of the cell growth, the study said.
The Zika virus is commonly spread by mosquitoes, though it can also be sexually transmitted.
But with its rapid spread in more than forty countries, especially South America and the Caribbean, it is suspected to be responsible for the unusually high number of cases of microcephaly and other severe syndromes, especially syndrome Guillain-Barré syndrome, which attacks the nervous system.
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“Much more research is needed to understand the link between Zika and microcephaly”, however believes Amelia Pinto, molecular microbiology professor at the University of St. Louis, Missouri. Already the CDC has updated its testing guidelines for Zika, recommending that pregnant women get tested 2-12 weeks after traveling to Zika infected areas even if they aren’t showing symptoms of the virus.
