Last Updated 09-Jul-2005

Mumps virus (MuV) is the type species of the genus Morbillivirus. Along with other members of the family Paramyxoviridae, MuV is an enveloped virus with a negative sense, single-stranded RNA genome. These viruses are 150-200nm in diameter with a helical nucleocapsid.

Other members of the family include human parainfluenzavirus 1 (HPIV-1; genus Respirovirus), human respiratory syncytial virus (hRSV or RSV; genus Pneumovirus), human parainfluenzavirus 2 and 4 (HPIV-2 and HPIV-4; genus Rubulavirus), measles virus (MeV; genus Morbillivirus), Hendravirus and Nipahvirus (genus Henipavirus) and human metapneumovirus (hMPV; genus Metapneumovirus).

A distinguishing feature among genera is the possession (Paramyxovirus) or absence (e.g. Morbilliviruis and Pneumovirus) of neuraminidase (NA).

Figure 1.
Schematic representation of the mumps virus (MuV) (-)ssRNA genome. Based on GenBank accession no. NC_001498.

Pathology:

• Droplets spread the infection via saliva and secretions from the respiratory tract.
• Incubation period of 2-3 weeks
• Malaise and fever is followed within a day by painful enlargement of one or both of the parotid (salivary) glands
• A possible complication in males after puberty is orchitis - painful swelling of one or both testicles.
• Inflammation of the ovary and pancreas can also occur.
• Disease is usually self-limiting within a few days
• Aseptic meningitis (usually resolving without problems) or postexposure encephalitis (can prove fatal) are the most serious complications associated with mumps.

Vaccination:

• Using a live attenuated vaccine (single serotype) administered between one and 1.5 years.