Cause[edit]
The mumps virus is an enveloped single-stranded, linear negative-sense RNA virus of the Rubulavirus genus and Paramyxovirus family. The genome consists of 15,384 bases encoding nine proteins. Proteins involved in viral replication are the nucleoprotein, phosphoprotein, and polymerase protein while the genomic RNA forms the ribonucleocapsid.[3][7][9] Humans are the only natural host for the virus.
Mumps is spread from person to person through contact with respiratory secretions, such as saliva from an infected person.[7] When an infected person coughs or sneezes, the droplets aerosolize and can enter the eyes, nose, or mouth of another person. Mumps can also be spread by sharing food and drinks. The virus can also survive on surfaces and then be spread after contact in a similar manner. A person infected with mumps is contagious from approximately 7 days before the onset of symptoms until about 8 days after symptoms start.[10] The incubation period (time until symptoms begin) can be from 12–25 days, but is typically 16–18 days.[10] 20-40% of persons infected with the mumps virus do not show symptoms, so it is possible to be infected and spread the virus without knowing it.[10]