Mumps virus (paramyxovirus) is the causative agent of Mumps (or epidemic parotitis).Mumps occurs worldwide. Generalized contamination levels are already high in childhood. The viruses are spread from person to person by saliva droplets or direct contact with articles that have been contaminated with infected saliva. Unvaccinated children between the ages of 2 and 12 are most commonly infected, but the infection can occur in other age groups.The incubation period is usually 12-26 days. The virus primary infects the epithel of the upper respiratory tract, gastrointestinal tract or eyes. After initial replication the virus causes a viremia, after which a parotitis is the main development as well as, fairly frequently, mumps meningitis. Painful swelling of the salivary glands (classically the parotid glands on one or both sides) and fever is the most typical presentation. Painful testicular swelling and rash may also occur. Fever lasts for 3-5 days, may reach up to 39°C.Complications include infection of various glandular organs (salivary gland, mammary gland, testes, ovaries, ZNS, pancreas and prostate). Orchitis (swelling of the testes) may occur in post puberty boys who contact mumps, but sterility only rarely ensues. In older people the central nervous system, the pancreas, the prostate, the breasts and other organs may be involved. Befall of the pancreas is painful accompanied by feeling of sickness and vomiting.