Editing Leprosy (section)

== Infection of animals ==
Between 15 and 20% of [[nine-banded armadillos]] (''Dasypus novemcinctus'') in the south-central United States carry ''M. leprae''.<ref>{{cite journal | vauthors = Truman R | title = Leprosy in wild armadillos | journal = Leprosy Review | volume = 76 | issue = 3 | pages = 198–208 | date = September 2005 | pmid = 16248207 | doi = 10.47276/lr.76.3.198 | doi-access = free }}</ref><ref name=":1">Liang, Jiayu (10/16/2023). "Leprosy in Florida: medical experts monitoring unusual, new cases of Hansen's disease". ''University of Florida Emerging Pathogens Institute''. [https://epi.ufl.edu/2023/10/16/leprosy-in-florida-medical-experts-monitoring-unusual-new-cases-of-hansens-disease/#:~:text=A%20major%20hint%20that%20someone,leprae%20bacteria. https://epi.ufl.edu/2023/10/16/leprosy-in-florida-medical-experts-monitoring-unusual-new-cases-of-hansens-disease/#:~:text=A%20major%20hint%20that%20someone,leprae%20bacteria.]</ref> As a result of their low body temperature their tissues commonly contain massive numbers of organisms which help in the dissemination of the infection. Armadillos were first demonstrated in 1971 to develop leprosy after inoculation with ''M. leprae''.<ref name=":0">Adams L. B. (2021). Susceptibility and resistance in leprosy: Studies in the mouse model. ''Immunological reviews'', ''301''(1), 157–174. <nowiki>https://doi.org/10.1111/imr.12960</nowiki></ref> Because of armadillos' armor, skin lesions are difficult to ascertain.<ref>{{cite journal | vauthors = Sharma R, Lahiri R, Scollard DM, Pena M, Williams DL, Adams LB, Figarola J, Truman RW | title = The armadillo: a model for the neuropathy of leprosy and potentially other neurodegenerative diseases | journal = Disease Models & Mechanisms | volume = 6 | issue = 1 | pages = 19–24 | date = January 2013 | pmid = 23223615 | pmc = 3529335 | doi = 10.1242/dmm.010215 }}</ref> Abrasions around the eyes, nose, and feet are the most common signs. Infected armadillos make up a large reservoir of ''M. leprae'' and may be a source of infection for some humans in the United States or other locations in the armadillos' home range. In armadillo leprosy, lesions do not persist at the site of entry in animals; ''M. leprae'' multiply in [[macrophage]]s at the site of [[inoculation]] and lymph nodes.<ref>{{cite journal | vauthors = Job CK, Drain V, Truman R, Deming AT, Sanchez RM, Hastings RC | title = The pathogenesis of leprosy in the nine-banded armadillo and the significance of IgM antibodies to PGL-1 | journal = Indian Journal of Leprosy | volume = 64 | issue = 2 | pages = 137–151 | date = April 1992 | pmid = 1607712 | id = {{INIST|4390813}} }}</ref>

Armadillos have been used in immunological research to fight leprosy. Some notable reagents include recombinant interleukin-2 and recombinant interferon-gamma reagents.<ref name=":0" /> Additionally, they have been key and have been useful models of leprosy for studies regarding neuropathy.<ref name=":2">Truman, R. W., Ebenezer, G. J., Pena, M. T., Sharma, R., Balamayooran, G., Gillingwater, T. H., Scollard, D. M., McArthur, J. C., & Rambukkana, A. (2014). The armadillo as a model for peripheral neuropathy in leprosy. ''ILAR journal'', ''54''(3), 304–314. <nowiki>https://doi.org/10.1093/ilar/ilt050</nowiki></ref> In clinical procedures such as electrophysiological nerve conduction tests Armadillo's nerve function has been properly assessed.<ref name=":2" /> Despite the studies mentioned regarding Armadillo's relationship to neuropathy and other effects of leprosy, there is still a lack of proper study on armadillos, and in conducting more armadillo-specific regents our understanding of leprosy’s effects on armadillos and possible humans can be found. Armadillos are a key component of modern-day research on leprosy.

There is a stigma surrounding armadillos and the carrying of leprosy. Because many people do not understand armadillos very well it is common for people to think of them as being dangerous to society and as a result valuing their lives less than other animals. It has become more common in parts of America for people to eat raw or undercooked armadillo, making the chances high that if not properly handled with care, one may become infected.<ref>Bittel, Jason (06/28/2016). [https://www.nationalgeographic.com/animals/article/Armadillos-leprosy-bacteria-amazon-brazil-nine-banded-animals# "Humans Gave Leprosy to Armadillos. Now, They're Giving It Back"]. ''National Geographic''.</ref>

An outbreak in chimpanzees in West Africa is showing that the bacteria can infect another species and also possibly have additional rodent hosts.<ref>{{cite web |url=https://www.science.org/content/article/leprosy-ancient-scourge-humans-found-assail-wild-chimpanzees |title=Leprosy, ancient scourge of humans, found to assail wild chimpanzees |work=Science |vauthors=Kupferschmidt K |date=11 November 2020 |access-date=1 July 2021 |archive-date=13 October 2021 |archive-url=https://web.archive.org/web/20211013190915/https://www.science.org/content/article/leprosy-ancient-scourge-humans-found-assail-wild-chimpanzees |url-status=live }}</ref> Studies have demonstrated that the disease is endemic in the UK red Eurasian squirrel population, with ''M. leprae'' and ''M. lepromatosis'' appearing in different populations. The ''M. leprae'' strain discovered on [[Brownsea Island]] is equated to one thought to have died out in the human population in mediaeval times.<ref>{{cite web |url=https://www.researchgate.net/publication/332568227 |title=Leprosy in Red Squirrels in the UK |work=Vet Record |date=30 March 2019 |access-date=25 May 2022}}</ref> Despite this, and speculation regarding past transmission through trade in squirrel furs, there does not seem to be a high risk of squirrel to human transmission from the wild population. Although leprosy continues to be diagnosed in immigrants to the UK, the last known human case of leprosy arising in the UK was recorded over 200 years ago.<ref>{{cite web |url=https://www.theguardian.com/science/2017/oct/25/medieval-love-of-squirrel-fur-may-have-helped-spread-leprosy-study-reveals |title=Medieval love of squirrel fur may have helped spread leprosy, study reveals |work=Guardian |date=25 October 2017 |access-date=25 May 2022 |archive-date=25 May 2022 |archive-url=https://web.archive.org/web/20220525101307/https://www.theguardian.com/science/2017/oct/25/medieval-love-of-squirrel-fur-may-have-helped-spread-leprosy-study-reveals |url-status=live }}</ref>

It has been shown that leprosy can reprogram cells in mouse<ref>{{cite journal |vauthors=Masaki T, Qu J, Cholewa-Waclaw J, Burr K, Raaum R, Rambukkana A |title=Reprogramming adult Schwann cells to stem cell-like cells by leprosy bacilli promotes dissemination of infection |journal=Cell |volume=152 |issue=1–2 |pages=51–67 |date=January 2013 |pmid=23332746 |pmc=4314110 |doi=10.1016/j.cell.2012.12.014}}</ref><ref>{{Cite news |date=17 January 2013 |title=Leprosy bacteria use 'biological alchemy' |work=BBC News |url=https://www.bbc.com/news/health-21056644 |access-date=18 November 2022 |archive-date=18 November 2022 |archive-url=https://web.archive.org/web/20221118021715/https://www.bbc.com/news/health-21056644 |url-status=live }}</ref> and armadillo<ref>{{cite journal | vauthors = Hess S, Kendall TJ, Pena M, Yamane K, Soong D, Adams L, Truman R, Rambukkana A | title = In vivo partial reprogramming by bacteria promotes adult liver organ growth without fibrosis and tumorigenesis | journal = Cell Reports. Medicine | volume = 3 | issue = 11 | pages = 100820 | date = November 2022 | pmid = 36384103 | doi = 10.1016/j.xcrm.2022.100820 | pmc = 9729881 | s2cid = 253577148 | doi-access = free }}</ref><ref>{{Cite news |date=16 November 2022 |title=Leprosy: Ancient disease able to regenerate organs |work=BBC News |url=https://www.bbc.com/news/health-63626239 |access-date=18 November 2022 |archive-date=18 November 2022 |archive-url=https://web.archive.org/web/20221118020211/https://www.bbc.com/news/health-63626239 |url-status=live }}</ref> models, similar to how [[induced pluripotent stem cell]]s are generated by the [[transcription factors]] [[Myc]], [[Oct-4|Oct3/4]], [[Sox2]], and [[Klf4]]. A notable study conducted by [[Charles C. Shepard|Charles Shepard]] used mice to find how leprosy, an infection that has a preference for cooler areas of the body, would work in a warm-blooded animal. This mice study helped further the understanding of how leprosy works in humans. This was called "The Mouse Model."<ref name=":0" /> The main findings were that even in mice whose immune systems were severely impaired and at a perceived high risk of developing leprosy, the body was still in most cases able to fight off leprosy. The findings suggest that in mice, the body will use their body's energy to fight leprosy.<ref name=":0" /> Using The Mouse Model Shepard was able to conduct new research regarding leprosy. This model can now be used as a tool to further study ''M. leprae''.<ref name=":0" /> The Mouse Model takes a more easily accessible animal model to better understand this complex disease. There are a few other up-and-coming models for ''M. leprae'' including the use of other animals including but not limited to mammals, birds, and cold-blooded animals.<ref name=":0" /> These animals do not tend to give as great results as armadillos and mice as different animals have different levels of disease resistance.