The Zika virus pandemic has been one of the big news stories of 2016. Why should a virus that causes mild discomfort in adults be so prominent in the news? One of the main reasons is the corresponding microcephaly pandemic, which is suspected to be caused by zika.
Zika Virus And Birth Defects
Microcephaly is a birth defect that results in babies with undersized heads and smaller brains. It is believed that the zika infection can be passed from a pregnant mother to her foetus. This secondary infection results in brain and physical deformities in the growing child. This is all still only a working hypothesis, however. Scientists did not know how zika may damage unborn babies’ brains.
Now researchers at Johns Hopkins University School of Medicine, Florida State University, and Emory University think that they may have found the answer. The scientists exposed lab-grown stem cells to the zika virus. They found that the virus infects cells from the brain’s outer layer, the cortex. The effects were devastating. Not only were these infected cells more likely to die, they were also less likely to divide to create new brain cells.
Viruses work by reprogramming infected human cells to produce multiple copies of the virus itself. After exposure, 90% of the studied brain cells were infected after only three days. These hijacked cortical brain cells then started churning out copies of the zika virus instead of new brain cells.
Of course, stem cells in a lab setting is a different thing to a foetus in a womb. But the research does suggest a likely biological reason for the zika-microcephaly link.
“While this study doesn’t definitely prove that Zika virus causes microcephaly, it’s very telling that the cells that form the cortex are potentially susceptible to the virus, and their growth could be disrupted by the virus.” – Guo-li Ming, M.D., Ph.D., professor of neurology, neuroscience, and psychiatry and behavioral science at Johns Hopkins’ Institute for Cell Engineering
This research could be built upon to screen drugs that could protect the cortical cells from infection. Researchers from around the globe are working hard to tackle the problems posed by Zika. The John Hopkins’ team are understandably excited by their apparent breakthrough and I, for one, applaud their efforts!
Zika Virus : Quick Facts
It is spread by two types of mosquito – Aedes aegypti and Aedes albopictus (“Asian tiger”)
It is believed to cause Microcephaly and Guillain–Barré syndrome
So far it is predominant in the South Americas (see map below)
Symptoms in adults may include : headaches, rash, joint pain, sore or red eyes and fever.
Many adults experience no symptoms.
Symptoms of microcephaly babies may include: small head size, seizures, hyperactivity, sloping forehead and delayed development.
Current attempts to halt the zika virus outbreak are concentrating on reducing the numbers of mosquitoes in affected areas.
There is no cure fro microcephaly and a vaccine probably won’t be available for several years.
Countries affected by the Outbreak
Map of countries affected by the Zika pandemic, courtesy of Wikipedia Commons.