Friday, August 26, 2016 Zika Virus Effects Go Beyond Microcephaly, Guillain-Barré, Say Researchers Medical experts have long known of the link between microcephaly and Zika virus infections in expectant mothers. But new research is shedding light on the extent of virus' effects—both on fetal and adult brains. A cranial imaging study in the journal Radiologyhas found other severe brain abnormalities in Brazilian babies with congenital Zika virus infection, even in those with typical head circumference at birth. Radiologists identified ventriculomegaly in 43 out of 45 infants with confirmed or presumed Zika infections. Authors hypothesize that these larger-than-normal fluid-filled structures in the brain, as well as cerebral atrophy, are responsible for the often unusual skull shape in these infants; essentially, the baby’s soft skull collapses as the brain shrinks. Researchers also observed calcium deposits in most cases. In 38 of the infants, the corpus callosum, which connects the 2 sides of the brain, was thin, malformed, underdeveloped, or completely absent. Several of the infants had incomplete or atrophied brainstems, and in all but 1 case had abnormal migration of neurons in the cerebral cortex. Co-author Deborah Levine, MD, told the Washington Post, “The likelihood the babies in our series are going to have normal development because of so many abnormalities — the prognosis is not good.” Public health officials continue to focus on warning pregnant women to avoid exposure to the virus. However, a new study in Cell Stem Cell indicates the potential for the virus to affect adult brain cells as well. Study authors examined the 2 areas of the adult brain that still contain neural stem cells. Adult mice injected with Zika virus experienced nerve cell death and generated fewer new nerve cells compared with the control group. While researchers don’t know the exact ramifications yet, it's already understood that cognitive decline, Alzheimer’s disease, and other neurological conditions are associated with deficits in new nerve cells. Co-author Sujan Shresta also suggests that “infection of adult neural progenitor cells could be the mechanism behind” the development of Guillain-Barré syndrome in adults who have previously been infected with Zika virus. The Centers for Disease Control and Prevention (CDC) have issued an advisory for people living in or traveling to South Florida, as Miami-Dade County has experienced 29 locally acquired cases. Officials worry that Zika will spread to Texas and Louisiana, due to the standing water from massive storms and flooding. The CDC awarded $6.8 million to a number of national public health organizations to help with mosquito surveillance and public awareness efforts. For the most up-to-date Zika research, see the World Health Organization open access studies, and the Pan American Health Organization list of published research, and the BMJ free access content.