Editing Rabies (section)

== Transmission ==
{{Main|Rabies transmission}}

All [[warm-blooded]] species, including humans, may become infected with the rabies virus and develop symptoms. [[Bird]]s were first artificially infected with rabies in 1884; however, infected birds are largely, if not wholly, asymptomatic, and recover.<ref name="serological">{{cite journal | vauthors = Shannon LM, Poulton JL, Emmons RW, Woodie JD, Fowler ME | title = Serological survey for rabies antibodies in raptors from California | journal = Journal of Wildlife Diseases | volume = 24 | issue = 2 | pages = 264–7 | date = April 1988 | pmid = 3286906 | doi = 10.7589/0090-3558-24.2.264 | doi-access = free }}</ref> Other bird species have been known to develop rabies [[antibody|antibodies]], a sign of infection, after feeding on rabies-infected mammals.<ref name="pmid16498885">{{cite journal | vauthors = Gough PM, Jorgenson RD | title = Rabies antibodies in sera of wild birds | journal = Journal of Wildlife Diseases | volume = 12 | issue = 3 | pages = 392–5 | date = July 1976 | pmid = 16498885 | doi = 10.7589/0090-3558-12.3.392 | doi-access = free }}</ref><ref name="Owls">{{cite journal | vauthors = Jorgenson RD, Gough PM, Graham DL | title = Experimental rabies in a great horned owl | journal = Journal of Wildlife Diseases | volume = 12 | issue = 3 | pages = 444–7 | date = July 1976 | pmid = 16498892 | doi = 10.7589/0090-3558-12.3.444 | s2cid = 11374356 | url = https://www.semanticscholar.org/paper/224b35832b9cace98ad3035260cfed2f894f9228 }}</ref>

The virus has also adapted to grow in cells of [[poikilotherm|cold-blooded]] vertebrates.<ref>{{cite web|url=http://virology-online.com/viruses/Rhabdoviruses.htm |title=Rabies |last=Wong |first=Derek | name-list-style = vanc |publisher=Wong's Virology |access-date=19 March 2009 |url-status=live |archive-url=https://web.archive.org/web/20081203053955/http://virology-online.com/viruses/Rhabdoviruses.htm |archive-date=3 December 2008 }}</ref><ref>{{cite book|title=Developments in Veterinary Virology: Rabies|last1=Campbell |first1=James B. |last2=Charlton |first2=K.M. | name-list-style = vanc |publisher=Springer|year=1988|page=48|isbn=978-0-89838-390-4}}</ref> Most animals can be infected by the virus and can transmit the disease to humans. Worldwide, about 99% of human rabies cases come from domestic dogs.<ref>{{cite web|url=https://www.who.int/news-room/fact-sheets/detail/rabies| title=Rabies| website=World Health Organization| date=21 April 2020| access-date=3 May 2021}}</ref> Other sources of rabies in humans include [[bat]]s,<ref name="pmid13858519">{{cite journal | vauthors = Pawan JL | title = The transmission of paralytic rabies in Trinidad by the vampire bat (Desmodus rotundus murinus Wagner | journal = Caribbean Medical Journal | volume = 21 | pages = 110–36 | year = 1959 | pmid = 13858519 }}</ref><ref name="pmid14431118">{{cite journal | vauthors = Pawan JL | title = Rabies in the vampire bat of Trinidad, with special reference to the clinical course and the latency of infection | journal = Caribbean Medical Journal | volume = 21 | pages = 137–56 | year = 1959 | pmid = 14431118 }}</ref> [[monkey]]s, [[raccoon]]s, [[fox]]es, [[skunk]]s, [[cattle]], [[wolf|wolves]], [[coyotes]], [[cat]]s, and [[mongoose]]s (normally either the small Asian mongoose or the yellow mongoose).<ref>{{cite journal | vauthors = Taylor PJ | title = A systematic and population genetic approach to the rabies problem in the yellow mongoose (Cynictis penicillata) | journal = The Onderstepoort Journal of Veterinary Research | volume = 60 | issue = 4 | pages = 379–87 | date = December 1993 | pmid = 7777324 }}</ref>

Rabies may also spread through exposure to infected [[bears]], [[livestock|domestic farm animals]], [[groundhog]]s, [[weasel]]s, and other [[Carnivora|wild carnivorans]]. However, [[lagomorphs]], such as [[hare]]s and [[rabbit]]s, and small [[rodent]]s such as [[chipmunk]]s, [[Gerbillinae|gerbil]]s, [[guinea pig]]s, [[hamster]]s, [[mice]], [[rat]]s, and [[squirrel]]s, are almost never found to be infected with rabies and are not known to transmit rabies to humans.<ref>{{cite web|url=https://www.cdc.gov/rabies/exposure/animals/other.html |title=Rabies. Other Wild Animals: Terrestrial carnivores: raccoons, skunks and foxes. |access-date=2010-12-23 |publisher=[[Centers for Disease Control and Prevention]](CDC) |url-status=live |archive-url=https://web.archive.org/web/20101220085305/http://www.cdc.gov/rabies/exposure/animals/other.html |archive-date=20 December 2010 }}</ref> Bites from mice, rats, or squirrels rarely require rabies prevention because these rodents are typically killed by any encounter with a larger, rabid animal, and would, therefore, not be carriers.<ref>{{cite book| last1 = Anderson | first1 = Janet | last2 = Frey | first2 = Rebecca | chapter = Rabies | veditors =  Fundukian LJ | title = Gale Encyclopedia of Medicine|edition= 3rd |date= 2006}}</ref> The [[Virginia opossum]] has a lower internal body temperature than the rabies virus prefers and therefore is resistant but not immune to rabies.<ref>{{cite journal | vauthors = McRuer DL, Jones KD | title = Behavioral and nutritional aspects of the Virginian opossum (Didelphis virginiana) | journal = The Veterinary Clinics of North America. Exotic Animal Practice | volume = 12 | issue = 2 | pages = 217–36, viii | date = May 2009 | pmid = 19341950 | doi = 10.1016/j.cvex.2009.01.007 }}</ref>

The virus is usually present in the nerves and [[saliva]] of a symptomatic rabid animal.<ref>{{cite book|title=The Merck Manual|edition= 11th |date=1983|page= 183}}</ref><ref>{{cite book |title=The Merck manual of Medical Information|edition= Second Home|date=2003|page= 484}}</ref> The route of [[infection]] is usually, but not always, by a bite. In many cases, the infected animal is exceptionally aggressive, may attack without provocation, and exhibits otherwise uncharacteristic behavior.<ref>{{cite web|last=Turton |first=Jenny | name-list-style = vanc |title=Rabies: a killer disease |publisher=National Department of Agriculture |year=2000 |url=http://www.nda.agric.za/docs/rabies/rabies.htm |url-status=live |archive-url=https://web.archive.org/web/20060923103559/http://www.nda.agric.za/docs/rabies/rabies.htm |archive-date=23 September 2006 }}</ref> This is an example of a viral pathogen [[Behavior-altering parasites and parasitoids|modifying the behavior of its host]] to facilitate its transmission to other hosts. After a typical human infection by bite, the virus enters the [[peripheral nervous system]]. It then travels along the [[Afferent nerve fiber|afferent nerve]]s toward the [[central nervous system]].<ref>{{cite book| last1 = Jackson | first1 = Alan C. | last2 = Wunner | first2 = William H. | name-list-style = vanc |title=Rabies |url=https://books.google.com/books?id=p8rMezRaD4oC&pg=PA290 |year=2002 |publisher=Academic Press |isbn=978-0-12-379077-4 |page=290 |url-status=live |archive-url=https://web.archive.org/web/20140108014518/http://books.google.com/books?id=p8rMezRaD4oC&pg=PA290 |archive-date=8 January 2014 }}</ref> During this phase, the virus cannot be easily detected within the host, and vaccination may still confer cell-mediated immunity to prevent symptomatic rabies. When the virus reaches the [[brain]], it rapidly causes [[encephalitis]], the prodromal phase, which is the beginning of the symptoms. Once the patient becomes symptomatic, treatment is almost never effective and mortality is over 99%. Rabies may also inflame the [[spinal cord]], producing [[transverse myelitis]].<ref name="LynnNewton2012">{{cite book|vauthors=Lynn DJ, Newton HB, Rae-Grant AD|title=The 5-Minute Neurology Consult|url=https://books.google.com/books?id=kTzlC4UbFdcC&pg=PA414|year=2012|publisher=Lippincott Williams & Wilkins |isbn=978-1-4511-0012-9 |pages=414–}}</ref><ref>{{cite book|last1=Davis |first1= Larry Ernest |last2=King |first2= Molly K.|last3=Schultz|first3=Jessica L. | name-list-style = vanc |title=Fundamentals of neurologic disease |url=https://books.google.com/books?id=moRp2jWZp0QC&pg=PA73 |date=15 June 2005 |publisher=Demos Medical Publishing |isbn=978-1-888799-84-2 |page=73 |url-status=live |archive-url=https://web.archive.org/web/20140108015452/http://books.google.com/books?id=moRp2jWZp0QC&pg=PA73 |archive-date=8 January 2014 }}</ref>

Although it is theoretically possible for rabies-infected humans to transmit it to others by biting or otherwise, no such cases have ever been documented, since infected humans are usually hospitalized and necessary precautions taken. Casual contact, such as touching a person with rabies or contact with non-infectious fluid or tissue (urine, blood, feces) does not constitute an exposure and does not require post-exposure prophylaxis. But as the virus is present in sperm and vaginal secretions, it might be possible for rabies to spread through sex.<ref>[https://rabiesalliance.org/rabies/what-is-rabies-and-frequently-asked-questions/exposure-prevention-treatment RabiesAlliance.org] {{webarchive|url=https://web.archive.org/web/20160924072630/https://rabiesalliance.org/rabies/what-is-rabies-and-frequently-asked-questions/exposure-prevention-treatment |date=24 September 2016 }}</ref> There are only a handful of recorded cases of human-to-human transmission of rabies, and all occurred through [[organ transplant]]s from infected donors.<ref>{{cite journal | vauthors = Srinivasan A, Burton EC, Kuehnert MJ, Rupprecht C, Sutker WL, Ksiazek TG, Paddock CD, Guarner J, Shieh WJ, Goldsmith C, Hanlon CA, Zoretic J, Fischbach B, Niezgoda M, El-Feky WH, Orciari L, Sanchez EQ, Likos A, Klintmalm GB, Cardo D, LeDuc J, Chamberland ME, Jernigan DB, Zaki SR | display-authors = 6 | title = Transmission of rabies virus from an organ donor to four transplant recipients | journal = The New England Journal of Medicine | volume = 352 | issue = 11 | pages = 1103–11 | date = March 2005 | pmid = 15784663 | doi = 10.1056/NEJMoa043018 }}</ref><ref>{{cite web | title=Human Rabies Prevention --- United States, 2008 Recommendations of the Advisory Committee on Immunization Practices | website=Centers for Disease Control and Prevention | date=2008-05-23 | url=https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5703a1.htm | access-date=2020-02-11}}</ref>