The mystery disease in South Sudan has not been identified but is known to cause fever and unexplained bleeding. Above: an image of another hemorrhagic fever, Marburg virus, made with an electron microscope and then colorized.
The two pinkish spheres are the Zika virus (the one at left is depicted in cross section). Surrounded by blood plasma molecules, the virus is shown interacting with the receptors, colored green, on the surface of a cell.
David S. Goodsell