The research found that Zika infects laboratory-cultivated cortical neural progenitor cells equivalent to those that form the cortex during the development of the human brain, though that does not provide answers about what happens in the developing fetus or if it really causes a microcephalic baby to be born with that abnormally small head.
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Now a chilling new study, conducted by both American and Brazilian researchers, is driving home that warning.
The first study to follow Zika-infected women throughout their pregnancies found that a large percentage of them are carrying fetuses with birth defects, a finding likely to deepen concern about the current outbreak.
Many other questions about the Zika virus also remain unanswered, the researchers said.
The virus directly disrupted cell growth and function, while some cells died after being infected.
There is no vaccine to prevent Zika virus infection.
The team studied 88 pregnant women who went to a clinic at the Oswaldo Cruz Foundation in Rio de Janeiro with the intention of being tested for the virus. There have been no reported cases of the virus contracted from a mosquito bite within Missouri.
“This is truly the virus from hell”, said Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine. The study was published Friday in the journal Cell Stem Cell.
Among 42 Zika-positive women willing to undergo fetal ultrasound testing, a total of 12, or 29 percent, had abnormal readings. No such defects were observed in the ultrasounds of Zika-negative mothers.
And, although it might be logical to conclude from the study that the Zika virus attacks, damages and kills important cells that build the brain, Ming said they now have to “determine whether the Zika virus infection can lead to microcephaly in a different cultural model system, a three-dimensional model”. Two were born undersized, while a third was born at normal weight but with severe microcephaly, including eye lesions that could indicate blindness. The baby delivered by emergency C-section struggled initially but now also appears healthy, Nielsen said.
It is not clear whether the cells could defend themselves against the Zika virus in any way, which means researchers don’t know whether or how the virus is being cleared from the cells, the researchers said.
Mark Schleiss, professor at the University of Minnesota, who was not involved in the study, hailed the results as “a big step in the right direction” in terms of understanding the pathogenesis of Zika.
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For the study, the researchers used human stem cells that were engineered to produce cells similar to those that give rise to the brain’s cortex in human embryos.
