This transmission electron micrograph (TEM) revealed the presence of numerous paramyxovirus virions, which in this instance, were responsible for a case of the mumps. Paramyxoviruses are members of the family, Paramyxoviridae
, and those that cause mumps in humans belong to the genus, Rubulavirus
. The virus itself can present itself in a number of morphologic shapes, including spherical, and stand-like, or filamentous, ranging from 150nm to 200nm in diameter, and 1000nm to 10000nm in length. At its core lies a non-segmented, negative-sense RNA genome.