This 1973 negative stained transmission electron micrograph (TEM) depicted the ultrastructural features displayed by the mumps virus. The mumps virus replicates in the upper respiratory tract and is spread through direct contact with respiratory secretions or saliva or through fomites, i.e., inanimate objects that are contaminated by the virus, and are subsequently handled. The infectious period or time that an infected person can transmit mumps to a non-infected person is from 3 days before symptoms appear to about 9 days after the symptoms appear. The incubation time, which is the period from when a person is exposed to virus to the onset of any symptoms, can vary from 16 to 18 days (range 12-25 days).