Mumps virus causes mumps.
The incubation period is long and varies from 12 to 25 days. Most of the infections are asymptomatic. The onset of mumps is sudden.
Complications of mumps: Meningoencephalitis is the mostfrequent complication of mumps in childhood. Other rare complications include oophoritis, mastitis, pancreatitis, thy-roiditis, arteritis, thrombocytopenia, and pneumonia. Death due to mumps is rare.
Mumps is a highly communicable disease, occurring worldwide.
Mumps continues to remain endemic in many countries throughout the world, as the mumps vaccine is used in only 57% of the countries. In the absence of vaccination program, it often occurs as epidemics in children 5–15 years of age.
Humans are the only natural hosts of the mumps virus. No animal hosts are present. The infected patients are the source of infection. A patient remains infectious usually from 9 days prior to the onset of parotid swelling as long as 7 days after onset of the swelling. The infection is transmitted by direct person-to-person contact and also by inhalation of respiratory droplets. The unvaccinated people and immunocompromised people are at more risk to infection by mumps virus.