Testicular immunology
Mumps is a viral disease which causes swelling of the salivary glands and testes. The mumps virus lives in the upper respiratory tract and spreads through direct contact with saliva. Prior to widespread vaccination programs, it was a common childhood disease. Mumps is generally not serious in children, but in adults, where sperm have matured in the testis, it can cause more severe complications, such as infertility.
Sialadenitis
Bacterial sialadenitis is uncommon nowadays and is usually associated with sialoliths. A study involving hospitals in the United Kingdom found that the incidence of admissions for sialadenitis is 27.5 per million of the population, with the most common cause being mumps which causes a viral infection in the salivary gland. Ascending acute bacterial parotitis used to be a common perimortal event but today this is no longer the case due to antibiotics and basic modern care which means that patients will be much less likely to become dehydrated.