Editing Mumps (section)

==Transmission==
The mumps virus is mainly transmitted by inhalation or oral contact with respiratory droplets or secretions. In experiments, mumps could develop after [[inoculation]] either via the mouth or the nose. Respiratory transmission is also supported by the presence of MuV in cases of respiratory illness without parotitis, detection in nasal samples, and transmission between people in close contact.<ref name=rubin /> MuV is excreted in saliva from approximately one week before to eight days after the onset of symptoms,<ref name=su /> peaking at the onset of parotitis,<ref name=kutty /> though it has also been identified in the saliva of asymptomatic individuals.<ref name=rubin />

[[Vertical transmission|Mother-to-child transmission]] has been observed in various forms. In non-human primates, placental transmission has been observed, which is supported by the isolation of MuV from spontaneous and planned aborted fetuses during maternal mumps. MuV has also been isolated from newborns whose mother was infected. While MuV has been detected in breast milk, it is unclear if the virus can be transmitted through it.<ref name=rubin /> Other manners of transmission include direct contact with infected droplets or saliva, [[fomite]]s contaminated by saliva and possibly urine.<ref name=kutty /><ref name=davis /><ref name=masarani /> Most transmissions likely occur before the development of symptoms and up to five days after such time.<ref name=kutty />

In susceptible populations, a single case can cause up to twelve new ones. The period when a person is contagious lasts from two days before the onset of symptoms to nine days after symptoms have ceased. Asymptomatic carriers of the mump virus can also transmit the virus.<ref name=davis /> These factors are thought to be reasons why controlling the spread of mumps is difficult.<ref name=rubin /> Furthermore, reinfection can occur after natural infection or vaccination,<ref name=who /> indicating that lifelong immunity is not guaranteed after infection.<ref name=latner /> Vaccinated individuals who are infected appear to be less contagious than the unvaccinated.<ref name=kutty />

The average number of new cases generated from a single case in a susceptible population called the [[basic reproduction number]], is 4–7. Given this, it is estimated that a vaccination rate between 79 and 100% is needed to achieve [[herd immunity]]. Outbreaks continue to occur in places that have vaccination rates exceeding 90%, however, suggesting that other factors may influence disease transmission. Outbreaks that have occurred in these vaccinated communities typically occur in highly crowded areas such as schools and military dormitories.<ref name=ramanathan >{{cite journal |vauthors=Ramanathan R, Voigt EA, Kennedy RB, Poland GA |date=18 June 2018 |title=Knowledge gaps persist and hinder progress in eliminating mumps |journal=Vaccine |volume=36 |issue=26 |pages=3721–3726 |doi=10.1016/j.vaccine.2018.05.067 |pmc=6031229 |pmid=29784466 }}</ref>