Editing Mumps (section)

==Cause==
Mumps is caused by the [[mumps virus]] (MuV), scientific name ''Mumps orthorubulavirus'', which belongs to the ''[[Orthorubulavirus]]'' genus in the ''[[Paramyxoviridae]]'' family of viruses.<ref name=ictv >{{cite web |url=https://ictv.global/taxonomy/taxondetails?taxnode_id=201901635 |title=ICTV Taxonomy history: ''Mumps orthorubulavirus'' |author=<!--Not stated--> |website=International Committee on Taxonomy of Viruses (ICTV) |publisher=ICTV |access-date=30 October 2020}}</ref> Humans are the only natural [[Host (biology)|host]] of the mumps virus. MuV's genome is made of RNA and contains seven genes that encode nine proteins. In MuV particles, the genome is encased by a helical [[capsid]]. The capsid is surrounded by a [[viral envelope]] that has spikes protruding from its surface. MuV particles are pleomorphic in shape and range from 100 to 600 nanometers in diameter.<ref name=rubin /><ref name=cox >{{cite journal |vauthors=Cox RM, Plemper RK |date=June 2017 |title=Structure and organization of paramyxovirus particles |journal=Curr Opin Virol |volume=24 |pages=105–114 |doi=10.1016/j.coviro.2017.05.004 |pmc=5529233 |pmid=28601688 }}</ref><ref name=rima >{{cite journal |vauthors=Rima B, Balkema-Buschmann A, Dundon WG, Duprex P, Easton A, Fouchier R, Kurath G, Lamb R, Lee B, Rota P, Wang L |date=December 2019 |title=ICTV Virus Taxonomy Profile: ''Paramyxoviridae'' |url=https://talk.ictvonline.org/ictv-reports/ictv_online_report/negative-sense-rna-viruses/mononegavirales/w/paramyxoviridae |archive-url=https://web.archive.org/web/20200227180016/https://talk.ictvonline.org/ictv-reports/ictv_online_report/negative-sense-rna-viruses/mononegavirales/w/paramyxoviridae |url-status=dead |archive-date=27 February 2020 |journal=J Gen Virol |volume=100 |issue=12 |pages=1593–1954 |doi=10.1099/jgv.0.001328 |pmc=7273325 |pmid=31609197 |access-date=30 October 2020}}</ref>

The replication cycle of MuV begins when the spikes on its surface bond to a cell, which then causes the envelope to fuse with the host cell's [[cell membrane]], releasing the capsid into the host cell's [[cytoplasm]].<ref name=rubin /><ref name=najjar >{{cite journal |vauthors=Najjar FE, Schmitt AP, Dutch RE |date=7 August 2014 |title=Paramyxovirus glycoprotein incorporation, assembly and budding: a three-way dance for infectious particle production |journal=Viruses |volume=6 |issue=8 |pages=3019–3054 |doi=10.3390/v6083019 |pmc=4147685 |pmid=25105277 |doi-access=free }}</ref><ref name=harrison >{{cite journal |vauthors=Harrison MS, Sakaguchi T, Schmitt AP |date=September 2010 |title=Paramyxovirus assembly and budding: building particles that transmit infections |journal=Int J Biochem Cell Biol |volume=42 |issue=9 |pages=1416–1429 |doi=10.1016/j.biocel.2010.04.005 |pmc=2910131 |pmid=20398786 }}</ref> Upon entry, the viral [[RNA-dependent RNA polymerase]] (RdRp) [[Transcription (biology)|transcribes]] [[messenger RNA]] (mRNA) from the genome, which is then [[Translation (biology)|translated]] by the host cell's ribosomes to synthesize viral proteins. RdRp then begins replicating the viral genome to produce progeny.<ref name=rubin /><ref name=harrison /> Viral spike proteins fuse into the host cell's membrane, and new virions are formed at the sites beneath the spikes.<ref name=rubin /><ref name=najjar /><ref name=harrison /> MuV then utilizes host cell proteins to leave the host cell by [[Viral shedding|budding]] from its surface, using the host cell's membrane as the viral envelope.<ref name=najjar />

Twelve genotypes of MuV are recognized, named genotypes A to N, excluding E and M. These genotypes vary in frequency from region to region. For example, genotypes C, D, H, and J are more common in the western hemisphere, whereas genotypes F, G, and I are more common in Asia, although genotype G is considered to be a global genotype. Genotypes A and B have not been observed in the wild since the 1990s. MuV has just one serotype, so antibodies to one genotype are functional against all genotypes.<ref name=who /> MuV is a relatively stable virus and is unlikely to experience [[antigenic shift]]ing that may cause new strains to emerge.<ref name=davison />