THE DANGEROUS MOSQUITO
As the fetus's brain starts to grow, it creates pressure, which pushes on the skull and causes it to grow. But if something stops brain growth — such as a virus — pressure on the skull drops, and the skull can collapse down onto the brain.
The skin around the head continues to grow, Bale says. So the baby is born with wrinkles of skin at the back of the neck and a tiny skull. In some cases, the baby's head is as small as an orange, or about half the size of a healthy baby's head.
"It's quite remarkable what the Zika virus is doing to the brain of young infants," Bale says. "Many of them will die often in infancy, and the majority, if not all, will then have a long-term, severe developmental problems."
Zika Is Linked To Microcephaly, Health Agencies Confirm
Now scientists think they have an understanding about how Zika causes these severe brain malformations. The findings come from a series of mouse experiments, published Wednesday in three leading journals.
In one study, published in Nature, Alysson Muotri and his team at the University of California, San Diego, infected pregnant mice with Zika and looked to see how the virus harmed the baby mice.
"We detected the virus all over the mice and in different regions of the body," Muotri says.
But for some reason — and scientists don't know why yet — Zika is particularly attracted to brain cells. And once inside the cells, Muotri says, Zika turns them into viral factories that start producing huge amounts of virus. Until they burst.
"They explode, and more viral particles are released that can infect other cells. And they can just amplify themselves," Muotri says.
More and more brain cells get infected. More die. This cell death is already a problem for the fetus. It scars the brain and creates inflammation.
But the situation gets worse because the brain cells infected by Zika are extremely special. They're called neural progenitor cells. And they're responsible for building a large portion of the brain.
"These are fast-replicating cells that will give rise to billions of cells in our brains," Muotri says.
So if a fetus loses even just a small percentage of these cells, a portion of its brain will never develop. "And the impact later in life would be dramatic," he says.
In 2017, I wrote a Futiristic Thriller Series inspired by the Zika Virus.
A script for a Movie is being written.
Revenge of Zeeka: Five book Series