Clinical Information

Mumps virus, together with parainfluenza virus types 1-4, respiratory syncytial virus and measles virus are classified in the family Paramyxoviridae. Mumps is an acute infection, which causes the painful enlargement of the salivary glands in approximately 70% to 90% of children (4 to 15 years of age) who develop clinical disease. In 5% to 20% post pubertal individuals, testicular pain (orchitis) and abdominal pain (oophoritis in females) can occur. Other complications include pancreatitis (less than 5% of cases) and central nervous system disease (meningitis/encephalitis) that occur rarely (about 1 in 6000 cases of mumps). Widespread routine immunization of infants with attenuated mumps virus has changed the epidemiology of this virus infection. Since 1989, there has been a steady decline in reported mumps cases, from 5712 to 352 cases in 1999, the lowest total ever reported. There is only one serotype of mumps virus that infects humans. Mumps has been recognized since antiquity by virtue of the parotitis that is often a striking clinical feature of the disease. Generally, a mild childhood illness, the varied presentation of mumps reflects the widespread invasion of visceral organs and central nervous system that commonly follows infection with mumps virus.