Studies add more evidence of Zika's risk to pregnant women
Aylward added that evidence had also "continued to accumulate" in multiple studies linking Zika to microcephaly, a serious birth defect in which a baby is born with an abnormally small head and brain.
While the Zika virus has previously been found to infect a range of human cells types, the latest study reveals that human NPCs showed a greater susceptibility to infection than some other cell types, including human embryonic stem cells. At this crucial step, the researchers infected some of the cells with the Zika virus and left others alone.
Ming, a professor of neurology, neuroscience, and psychiatry and behavioral science at Johns Hopkins' Institute for Cell Engineering, led the research with Hongjun Song, a neuroscientist at Johns Hopkins, and Hengli Tang, a virologist at Florida State University.
According to the researchers, the Zika virus flourished in lab dishes containing these stem cells, causing either cell death or disruption of cell growth. Brazil is investigating more than 4,200 additional suspected microcephaly cases.
Zika is a mosquito-transmitted virus that can cause an array of mild symptoms, but has been linked to causing birth defects, such as microcephaly, which causes neurological problems and an under-developed head, if a pregnant woman is infected.
"We'll really see the impacts of Zika on newborns and pregnancy during the next two or three months", Rodriguez-Morales said. "Ultimately the proof would need to come from the clinical side and animal studies".
The researchers said the stem cells targeted by Zika are called cortical neural precursors, and they spawn the brain cells that make up the cerebral cortex, the outer layer of the brain's gray matter that's largely responsible for higher brain functions. More ominously, they're not sure if Zika is capable of infecting the small population of neural stem cells that adults keep above the brainstem in the hippocampus.
The person has recovered and is no longer infectious, the state Department of Health said Thursday. A number of other viruses are known to trigger the condition.
Next, the researchers tested the functional properties of their model by exposing it to a virus and to Toxoplasma gondi - a parasite found in cat feces that can lead to fetal infection, causing miscarriage, congenital disease and, or disability in later life. "The questions we address here are among the very first questions people want to know the answers of". A scarcity of birth control pills has also led to unwanted pregnancies in Venezuela, where abortion is banned unless a woman's health is at risk.
Obama has asked the U.S. Congress for more than $1.8 billion in emergency funding to fight the virus.
The WHO is set to begin a 3-day Zika countermeasure research and development meeting on Mar 7 to settle on which vaccines, drugs, diagnostic tests, and mosquito-control tools seem most promising. Induced pluripotent stem cells can give rise to any cell type in the body, including cortical neural progenitor cells. The institute now is monitoring 28 children with potential microcephaly, not all related to Zika, but so far no case of the defect is linked to the virus, the institute told Reuters.
The new results mark the first from a prospective study, which involves tracking the health of women who are infected with Zika and comparing them to very similar people who are not infected.
Of note is how Ming, Song, Tang, and their collaborator Peng Jin, a geneticist at the Emory University School of Medicine, assembled a group of experts from four labs with different research interests to quickly tackle the Zika public health emergency.
Seven women (16 percent) had fetuses with lesions on the brain or spinal cord, or other central nervous system problems, and 7 women appeared to have placental insufficiency, when the placenta doesn't work as it should so that the fetus does not receive a sufficient amount of oxygen and other nutrients.