Editing Brown rat (section)

==Diseases==
Similar to other [[rodents]], brown rats may carry a number of pathogens,<ref name=":8">{{cite journal |vauthors=Meerburg BG, Singleton GR, Kijlstra A |title=Rodent-borne diseases and their risks for public health|journal=Crit Rev Microbiol|volume=35 |issue=3|year=2009 |pmid=19548807|doi=10.1080/10408410902989837|pages=221–70|s2cid=205694138}}</ref><ref>{{Cite journal|last1=Kosoy|first1=Michael|last2=Khlyap|first2=Lyudmila|last3=Cosson|first3=Jean-Francois|last4=Morand|first4=Serge|date=2015-01-01|title=Aboriginal and Invasive Rats of Genus Rattus as Hosts of Infectious Agents|url=https://www.liebertpub.com/doi/10.1089/vbz.2014.1629|journal=Vector-Borne and Zoonotic Diseases|volume=15|issue=1|pages=3–12|doi=10.1089/vbz.2014.1629|pmid=25629775 |issn=1530-3667}}</ref> which can result in disease, including [[Weil's disease]], [[rat bite fever]], [[cryptosporidiosis]], [[viral hemorrhagic fever]], [[Q fever]] and [[hantavirus pulmonary syndrome]]. In the United Kingdom, brown rats are an important reservoir for ''[[Coxiella burnetii]],'' the bacterium that causes Q fever, with seroprevalence for the bacteria found to be as high as 53% in some wild populations.<ref>{{cite journal | doi = 10.1017/S0031182000081014 | pmid = 7845709 | last1 = Webster | first1 = JP | last2 = Lloyd | first2 = G | last3 = Macdonald | first3 = DW. | year = 1995 | title = Q fever (Coxiella burnetii) reservoir in wild brown rat (Rattus norvegicus) populations in the UK. | journal = Parasitology | volume = 110 | pages = 31–55 | s2cid = 21881010 }}</ref>

This species can also serve as a reservoir for ''[[Toxoplasma gondii]]'', the parasite that causes [[toxoplasmosis]], though the disease usually spreads from rats to humans when domestic cats feed on infected brown rats.<ref>{{cite journal | doi = 10.1016/S0304-4017(97)00227-6 | last1 = Dubeya | first1 = J. P. | last2 = Frenkel | first2 = J. K. | year = 1998 | title = Toxoplasmosis of rats: a review, with considerations of their value as an animal model and their possible role in epidemiology | url = https://zenodo.org/record/1260015| journal = [[Veterinary Parasitology (journal)|Veterinary Parasitology]] | volume = 77 | issue = 1| pages = 1–32 | pmid=9652380}}</ref> The parasite has a long history with the brown rat, and there are indications that the parasite has evolved to alter an infected rat's perception to [[Cat predation on wildlife|cat predation]], making it more susceptible to predation and increasing the likelihood of transmission.<ref>{{cite journal | doi=10.1098/rspb.2000.1182 | journal=[[Proceedings of the Royal Society B]] | last1=Berdoy | volume=267 | issue=1452 | pages=1591–1594 | first1=M | last2=Webster | first2=JP | last3=MacDonald | first3=DW | title=Fatal attraction in rats infected with Toxoplasma gondii. | year=2000 | pmid=11007336 | pmc=1690701 | jstor=2665707 }}</ref>

Surveys and specimens of brown rat populations throughout the world have shown this species is often associated with outbreaks of [[trichinosis]],<ref>Samuel et al. (2001) ''Parasitic Diseases of Wild Mammals.'' Blackwell Publishing. pp. 380–393. {{ISBN|0-8138-2978-X}}.</ref><ref>{{cite journal | doi = 10.2307/3282667 | last1 = Leiby | first1 = D. A. | last2 = Duffy | year = 1990 | first2 = C. H. | last3 = Darwin Murrell | first3 = K. | last4 = Schad | first4 = G. A. | title = Trichinella spiralis in an Agricultural Ecosystem: Transmission in the Rat Population | jstor = 3282667| journal = [[The Journal of Parasitology]] | volume = 76 | issue = 3| pages = 360–364 | pmid = 2352066 }}</ref> but the extent to which the brown rat is responsible in transmitting ''[[Trichinella]]'' larvae to humans and other synanthropic animals is at least somewhat debatable.<ref>{{cite journal | doi = 10.1645/GE-158R | last1 = Stojcevic | first1 = D | last2 = Zivicnjak | first2 = T| year = 2004 | last3 = Marinculic | first3 = A | last4 = Marucci | first4 = G | last5 = Andelko | first5 = G | last6 = Brstilo | first6 = M | last7 = Pavo | first7 = L | last8 = Pozio | first8 = E | title = The Epidemiological Investigation of Trichinella Infection in Brown Rats (Rattus norvegicus) and Domestic Pigs in Croatia Suggests That Rats are not a Reservoir at the Farm Level | journal = Journal of Parasitology | volume = 90 | issue = 3| pages = 666–670 | pmid = 15270124 | s2cid = 2297640 }}</ref> ''Trichinella pseudospiralis'', a parasite previously not considered to be a potential pathogen in humans or domestic animals, has been found to be pathogenic in humans and carried by brown rats.<ref>{{cite journal | doi=10.3201/eid0605.000517 | last1=Ranque | pages=543–547 | issue=5 | first1=S | volume=6 | last2=Faugère | journal=Emerging Infectious Diseases | first2=B | last3=Pozio | first3=E | last4=La Rosa | first4=G | last5=Tamburrini | first5=A | last6=Pellissier | first6=JF | last7=Brouqui | first7=P | title=Trichinella pseudospiralis outbreak in France. | year=2000 | pmid = 10998388 | pmc=2627956 }}</ref>

They can also be responsible for transmitting ''[[Angiostrongylus]]'' larvae to humans by eating raw or undercooked snails, slugs, molluscs, crustaceans, water and/or vegetables contaminated with them.<ref>{{Cite web|url=https://www.cdc.gov/dpdx/angiostrongyliasis_can/index.html|title=CDC - DPDx - Angiostrongyliasis cantonensis|date=2019-06-20|website=www.cdc.gov|language=en-us|access-date=2019-08-27}}</ref>

Brown rats are sometimes mistakenly thought to be a major reservoir of [[bubonic plague]], a possible cause of the [[Black Death]]. However, the bacterium responsible, ''[[Yersinia pestis]]'', is commonly endemic in only a few rodent species and is usually transmitted [[zoonosis|zoonotically]] by [[rat flea]]s—common carrier rodents today include [[Spermophilus|ground squirrels]] and [[wood rat]]s. However, brown rats may suffer from plague, as can many nonrodent species, including dogs, cats, and humans.<ref name=Merck>{{cite web |url=http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/51900.htm|title=Merck Veterinary Manual|access-date=11 January 2010|archive-url=https://web.archive.org/web/20160303183419/http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm%2Fbc%2F51900.htm|archive-date=3 March 2016}}</ref> During investigations of the plague epidemic in [[San Francisco]] in 1907, >1% of collected rats were infected with ''Y. pestis.''<ref name=":6" /> The original carrier for the plague-infected fleas thought to be responsible for the Black Death was the black rat, and it has been hypothesized that the displacement of black rats by brown rats led to the decline of bubonic plague.<ref>John M. Last. [http://www.enotes.com/public-health-encyclopedia/black-death "Black Death"], ''Encyclopedia of Public Health'', [[eNotes]] website. Retrieved 31 December 2010. *Ethne Barnes. ''Diseases and Human Evolution'', [[University of New Mexico Press]], 2007, {{ISBN|978-0-8263-3066-6}}, [https://books.google.com/books?id=wnlB7EMtqFYC&pg=PA247 p. 247].</ref> This theory has, however, been deprecated, as the dates of these displacements do not match the increases and decreases in plague outbreaks.<ref>{{cite book |author=Bollet, A.J. |year=2004 |title=Plagues & Poxes: The Impact of Human History on Epidemic Disease |location= |publisher=Demos Medical Publishing |pages= |chapter= |chapter-url= |isbn=978-1-888799-79-8 |url=https://books.google.com/books?id=bHIj5PJdZbkC&pg=PA23}}</ref><ref>{{cite book |author=Hays, J. N. |year=2005 |title=Epidemics and Pandemics: Their Impacts on Human History |publisher=ABC-CLIO |isbn=978-1-85109-658-9}}</ref>

During the [[COVID-19 pandemic]], one study of New York City sewer rats showed that 17 percent of the city's brown rat population had become infected with [[SARS-CoV-2]].<ref name="Geo 2023">{{cite news |last1=Main |first1=Douglas |title=COVID-19 is more widespread in animals than we thought |url=https://www.nationalgeographic.com/animals/article/how-so-many-animal-species-contract-covid |access-date=30 January 2023 |publisher=National Geographic |date=9 January 2023 |archive-url=https://web.archive.org/web/20230109182131/https://www.nationalgeographic.com/animals/article/how-so-many-animal-species-contract-covid |archive-date=9 January 2023}}</ref>