Editing Lassa fever (section)

===Spread===
[[File:Mastomys natalensis.jpg|left|thumb|''Mastomys natalensis'', the natural reservoir of the Lassa fever virus]]
Lassa virus commonly spreads to humans from other animals, specifically the ''[[Natal multimammate mouse]]'' or African rat, also called the Natal multimammate rat (''Mastomys natalensis'').<ref name=Rich2003>{{Cite journal|last1=Richmond|first1=J. K.|last2=Baglole|first2=D. J.|title=Lassa fever: Epidemiology, clinical features, and social consequences|doi=10.1136/bmj.327.7426.1271|journal=BMJ|volume=327|issue=7426|pages=1271–1275|year=2003|pmid=14644972|pmc=286250}}</ref> This is probably the most common mouse in equatorial Africa, common in human households and eaten as a delicacy in some areas.<ref name=Rich2003/><ref name=Werner2004>{{cite book|editor-last=Werner|editor-first=Dietrich|title=Biological Resources and Migration|publisher=Springer|year=2004|page=363|isbn=978-3-540-21470-0|url=https://archive.org/details/biologicalresour0000unse/page/363}}</ref>

The multimammate mouse can quickly produce a large number of offspring, tends to colonize human settlements, increasing the risk of rodent-human contact, and is found throughout the west, central and eastern parts of the African continent.<ref name=Go2012>{{cite journal|last1=Goeijenbier|first1=Marco|last2=Wagenaar|first2=Jiri|last3=Goris|first3=Marga|last4=Martina|first4=Byron|last5=Henttonen|first5=Heikki|last6=Vaheri|first6=Antti|last7=Reusken|first7=Chantal|last8=Hartskeerl|first8=Rudy|last9=Osterhaus|first9=Albert|last10=Van Gorp|first10=Eric|title=Rodent-borne hemorrhagic fevers: under-recognized, widely spread and preventable – epidemiology, diagnostics and treatment|journal=Critical Reviews in Microbiology|date=7 June 2012|volume=39|issue=1|pages=26–42|doi=10.3109/1040841X.2012.686481|pmid=22670688|s2cid=31217913|url=}}</ref>

Once the mouse has become a carrier, it will excrete the virus throughout the rest of its lifetime through feces and urine creating ample opportunity for exposure.<ref name=Go2012/> The virus is probably transmitted by contact with the feces or urine of animals accessing [[Cereal|grain]] stores in residences.<ref name=Werner2004/> No study has proven presence in breast milk, but the high level of [[viremia]] suggests it may be possible.<ref name=JAMA2018/>

Individuals who are at a higher risk of contracting the infection are those who live in rural areas where Mastomys are discovered, and where sanitation is not prevalent. Infection typically occurs by direct or indirect exposure to animal excrement through the [[respiratory tract|respiratory]] or gastrointestinal tracts. Inhalation of tiny particles of infectious material (aerosol) is believed to be the most significant means of exposure. It is possible to acquire the infection through broken [[human skin|skin]] or [[mucous membrane]]s that are directly exposed to infectious material. Transmission from person to person has been established, presenting a disease risk for healthcare workers. The virus is present in urine for between three and nine weeks after infection, and it can be transmitted in [[semen]] for up to three months after becoming infected.<ref name=Rich2003/><ref name=PHE>{{cite web|publisher=Public Health England|url=https://www.gov.uk/guidance/lassa-fever-origins-reservoirs-transmission-and-guidelines|title=Lassa fever: origins, reservoirs, transmission and guidelines|archive-url=https://web.archive.org/web/20160202152827/https://www.gov.uk/guidance/lassa-fever-origins-reservoirs-transmission-and-guidelines|archive-date=2 February 2016|date=5 September 2014|access-date=1 April 2016}}</ref><ref name=WHO>{{cite web|url=https://www.who.int/mediacentre/factsheets/fs179/en/|title=Lassa fever|work=Media Centre Fact Sheet No 179|publisher=World Health Organization|access-date=26 May 2015|url-status=live|archive-url=https://web.archive.org/web/20150605052251/http://www.who.int/mediacentre/factsheets/fs179/en/|archive-date=5 June 2015}}</ref>