The Zika virus is a single-stranded RNA virus in the Flaviviridae family. A near-atomic level visualization of Zika finds it to be most similar to the dengue virus. There is a difference in one surface protein (glycoprotein-180) that helps flaviviruses attach to human cells. This may explain how the Zika virus attacks nerve cells. This glycoprotein could further explain the association with Guillain-Barre syndrome and birth defects, such as microcephaly.