Mumps
Mumps is considered most contagious in the five days after the onset of symptoms, and isolation is recommended during this period. In someone who has been admitted to the hospital, standard and droplet precautions are needed. People who work in healthcare cannot work for five days.
Mumps rubulavirus
Electron microscopy (EM) revealed that the mumps virus (MuV), like other members of the Paramyxoviridae, has an enveloped virion of roughly spherical or pleiomorphic (variable) shape. Paramyxovirus particles can have sizes ranging from 120–450 nm in diameter.
These particles consist of what is known as a ribonucleoprotein (RNP) complex: a single-stranded, linear RNA genome coated by nucleocapsid proteins (NP) in association with an RNA polymerase complex of both large (L) and phosphoprotein (P) subunits. It has been estimated that over 2,000 such NP molecules coat the genome along with about 250 P and 25 L molecules.