Ebola

===Virology===
{{Main|Ebolavirus|l1=''Ebolavirus'' (taxonomic group)|Ebola virus|l2=Ebola virus (specific virus)}}
[[File:Ebola virus virion.jpg|thumb|[[Electron micrograph]] of an Ebola virus [[virion]]]]

Ebolaviruses contain single-stranded, non-infectious [[RNA]] [[genome]]s.<ref name="Fauquet2005">{{Cite book | vauthors = Pringle CR |title=Virus Taxonomy – Eighth Report of the International Committee on Taxonomy of Viruses |publisher=Elsevier/Academic Press |year=2005 |isbn=978-0-12-370200-5 | veditors = Fauquet CM, Mayo MA, Maniloff J, Desselberger U, Ball LA  |location=San Diego |pages=609–614 |chapter=Order Mononegavirales }}</ref> ''Ebolavirus'' genomes contain seven [[gene]]s including [[Three prime untranslated region|3'-UTR]]-''NP''-''VP35''-''VP40''-''GP''-''VP30''-''VP24''-''L''-[[Five prime untranslated region|5'-UTR]].<ref name="Feldmann2011" /><ref name="Stahelin2014">{{Cite journal |vauthors=Stahelin RV |date=June 2014 |title=Membrane binding and bending in Ebola VP40 assembly and egress |journal=Front Microbiol |volume=5 |page=300 |doi=10.3389/fmicb.2014.00300 |pmc=4061899 |pmid=24995005 |doi-access=free}}</ref> The genomes of the five different ebolaviruses (BDBV, EBOV, RESTV, SUDV and TAFV) differ in [[nucleic acid sequence|sequence]] and the number and location of gene overlaps. As with all [[filovirus]]es, ebolavirus virions are filamentous particles that may appear in the shape of a shepherd's crook, of a "U" or of a "6," and they may be coiled, toroid or branched.<ref name="Stahelin2014" /><ref>{{Cite journal |display-authors=6 |vauthors=Ascenzi P, Bocedi A, Heptonstall J, Capobianchi MR, Di Caro A, Mastrangelo E, Bolognesi M, Ippolito G |date=June 2008 |title=Ebolavirus and Marburgvirus: insight the Filoviridae family |url=https://air.unimi.it/retrieve/handle/2434/53604/1077822/Ebola_2008%29_Proofs.pdf |journal=Mol Aspects Med |volume=29 |issue=3 |pages=151–185 |doi=10.1016/j.mam.2007.09.005 |pmid=18063023 |hdl-access=free |hdl=2434/53604}}</ref> In general, ebolavirions are 80 nanometers (nm) in width and may be as long as 14,000&nbsp;nm.<ref name="Chippaux2014">{{Cite journal |vauthors=Chippaux JP |date=October 2014 |title=Outbreaks of Ebola virus disease in Africa: the beginnings of a tragic saga |journal=J Venom Anim Toxins Incl Trop Dis |volume=20 |issue=1 |page=44 |doi=10.1186/1678-9199-20-44 |pmc=4197285 |pmid=25320574 |doi-access=free }}</ref>

Their [[Biological life cycle|life cycle]] is thought to begin with a virion attaching to specific [[Cell surface receptor|cell-surface receptors]] such as [[C-type lectin]]s, [[DC-SIGN]], or [[integrin]]s, which is followed by fusion of the [[Pinocytosis|viral envelope with cellular membranes]].<ref name="Misasi2014">{{Cite journal |vauthors=Misasi J, Sullivan NJ |date=October 2014 |title=Camouflage and Misdirection: The Full-On Assault of Ebola Virus Disease |journal=Cell |volume=159 |issue=3 |pages=477–486 |doi=10.1016/j.cell.2014.10.006 |pmc=4243531 |pmid=25417101}}</ref> The virions taken up by the cell then travel to acidic [[endosome]]s and [[lysosome]]s where the viral envelope glycoprotein GP is cleaved.<ref name="Misasi2014" /> This processing appears to allow the virus to bind to cellular proteins enabling it to fuse with internal cellular membranes and release the viral [[nucleocapsid]].<ref name="Misasi2014" /> The ''Ebolavirus'' structural glycoprotein (known as GP1,2) is responsible for the virus' ability to bind to and infect targeted cells.<ref name="Kuhl2012">{{Cite journal |vauthors=Kühl A, Pöhlmann S |date=September 2012 |title=How Ebola virus counters the interferon system |journal=Zoonoses Public Health |volume=59 |issue=Supplement 2 |pages=116–131 |doi=10.1111/j.1863-2378.2012.01454.x |pmc=7165950 |pmid=22958256}}</ref> The viral [[RNA-dependent RNA polymerase|RNA polymerase]], encoded by the ''L'' gene, partially uncoats the nucleocapsid and [[Transcription (genetics)|transcribes]] the genes into positive-strand [[mRNA]]s, which are then [[translation (biology)|translated]] into structural and nonstructural proteins. The most abundant protein produced is the nucleoprotein, whose concentration in the host cell determines when L switches from gene transcription to genome replication. Replication of the viral genome results in full-length, positive-strand antigenomes that are, in turn, transcribed into genome copies of negative-strand virus progeny.<ref name="Olejnik2011" /> Newly synthesised structural proteins and genomes self-assemble and accumulate near the inside of the [[cell membrane]]. Virions [[Budding|bud]] off from the cell, gaining their envelopes from the cellular membrane from which they bud. The mature progeny particles then infect other cells to repeat the cycle. The genetics of the Ebola virus are difficult to study because of EBOV's virulent characteristics.<ref name="Feldmann2005">{{Cite book | vauthors = Feldmann H, Geisbert TW, Jahrling PB, Klenk H, Netesov SV, Peters CJ, Sanchez A, Swanepoel R, Volchkov VE |title=Virus Taxonomy – Eighth Report of the International Committee on Taxonomy of Viruses | publisher=Elsevier/Academic Press |year=2005 |isbn=978-0123702005 | veditors = Fauquet CM, Mayo MA, Maniloff J, Desselberger U, Ball LA  }}</ref>