Editing African trypanosomiasis (section)

===Vector===
{| class="wikitable" style = "float: right; margin-left:15px; text-align:center"
!Type
!''Trypanosoma''
!Distribution
!''V''ector
|-
|Chronic
|''[[Trypanosoma brucei gambiense|T. brucei gambiense]]''
|Western Africa
|''G. palpalis''
''G. tachinoides''

''[[Glossina fuscipes|G. fuscipes]]''

''G. morsitans''
|-
|Acute
|''[[Trypanosoma brucei rhodesiense|T. brucei rhodesiense]]''
|Eastern Africa
|''G. morsitans''
''G. swynnertoni''

''G. pallidipes''

''G. fuscipes''
|}
[[File:Tsetsemeyers1880.jpg|thumb|Drawing of a tsetse fly from 1880]]
The [[tsetse fly]] (genus ''Glossina'') is a large, brown, biting fly that serves as both a host and vector for the [[Trypanosoma brucei|trypanosome]] parasites. While taking blood from a mammalian host, an infected tsetse fly injects metacyclic trypomastigotes into skin tissue. Metacyclic trypomastigotes are the infectious form of the parasite that develops in the salivary glands of the vector and is transmitted through the bite. From the bite, parasites first enter the lymphatic system and then pass into the bloodstream. Inside the mammalian host, they transform into bloodstream trypomastigotes and are carried to other sites throughout the body, reach other body fluids (e.g., lymph, spinal fluid), and continue to replicate by [[binary fission]].<ref>{{cite journal | vauthors = Jamabo M, Mahlalela M, Edkins AL, Boshoff A | title = Tackling Sleeping Sickness: Current and Promising Therapeutics and Treatment Strategies | journal = International Journal of Molecular Sciences | volume = 24 | issue = 15 | page = 12529 | date = August 2023 | pmid = 37569903 | pmc = 10420020 | doi = 10.3390/ijms241512529 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Wamwiri FN, Changasi RE | title = Tsetse Flies (Glossina) as Vectors of Human African Trypanosomiasis: A Review | journal = BioMed Research International | volume = 2016 | page = 6201350 | date = 2016 | pmid = 27034944 | pmc = 4789378 | doi = 10.1155/2016/6201350 | doi-access = free }}</ref>
<ref name="transcript">{{Cite journal |last1=Christiano |first1=Romain |last2=Kolev |first2=Nikolay G. |last3=Shi |first3=Huafang |last4=Ullu |first4=Elisabetta |last5=Walther |first5=Tobias C. |last6=Tschudi |first6=Christian |date=October 2017 |title=The proteome and transcriptome of the infectious metacyclic form of Trypanosoma brucei define quiescent cells primed for mammalian invasion |journal=Molecular Microbiology |language=en |volume=106 |issue=1 |pages=74–92 |doi=10.1111/mmi.13754 |issn=0950-382X |pmc=5607103 |pmid=28742275}}</ref>

The entire life cycle of African trypanosomes is represented by extracellular stages. A tsetse fly becomes infected with bloodstream trypomastigotes when taking a blood meal on an infected mammalian host. The parasites then transform into procyclic trypomastigotes, specifically in the fly's midgut, multiply by binary fission, leave the midgut, and transform into epimastigotes. The epimastigotes reach the fly's salivary glands and continue multiplication by binary fission.<ref name="d672">{{cite web | title=Trypanosomiasis, African | website=CDC | date=2018-06-08 | url=https://www.cdc.gov/dpdx/trypanosomiasisafrican/index.html | access-date=2024-06-18}}</ref>

The entire life cycle of the fly takes about three weeks. In addition to the bite of the [[tsetse fly]], the disease can be transmitted by:
* Mother-to-child infection: the trypanosome can sometimes cross the placenta and infect the fetus.<ref>{{cite journal | vauthors = Olowe SA | title = A case of congenital trypanosomiasis in Lagos | journal = Transactions of the Royal Society of Tropical Medicine and Hygiene | volume = 69 | issue = 1 | pages = 57–59 | year = 1975 | pmid = 1170654 | doi = 10.1016/0035-9203(75)90011-5 }}</ref>
* Laboratories: accidental infections, for example, through the handling of blood of an infected person and organ transplantation, although this is uncommon.
* Blood transfusion
* [[Human sexual activity|Sexual contact]]<ref name="rocha">{{cite journal | vauthors = Rocha G, Martins A, Gama G, Brandão F, Atouguia J | title = Possible cases of sexual and congenital transmission of sleeping sickness | journal = Lancet | volume = 363 | issue = 9404 | page = 247 | date = January 2004 | pmid = 14738812 | doi = 10.1016/S0140-6736(03)15345-7 | s2cid = 5311361 }}</ref>
[[Horse-fly|Horse-flies]] ([[Horse-fly|Tabanidae]]) and [[stable fly|stable flies]] ([[Muscidae]]) possibly play a role in the transmission of [[nagana]] (the animal form of sleeping sickness) and the human disease form.<ref>{{cite journal | vauthors = Cherenet T, Sani RA, Panandam JM, Nadzr S, Speybroeck N, van den Bossche P | title = Seasonal prevalence of bovine trypanosomosis in a tsetse-infested zone and a tsetse-free zone of the Amhara Region, north-west Ethiopia | journal = The Onderstepoort Journal of Veterinary Research | volume = 71 | issue = 4 | pages = 307–312 | date = December 2004 | pmid = 15732457 | doi = 10.4102/ojvr.v71i4.250 | doi-access = free }}</ref> Studies have noted a strain of Tetste fly [[Glossina palpalis]] that has proved to pose a public health challenge in animal livestock because of a high carrier rate of DNA of trypanosome parasites. further studies can observe the carrier rate across a range of domestic animals in addition to determining the prevalence and risk factors of nagana in different seasons and establish seasonal variation in animal trypanosomiasis transmission.<ref name="pigs in Ghana">{{Cite journal |last1=Tweneboah |first1=Austine |last2=Rosenau |first2=Jana |last3=Addo |first3=Kofi Agyapong |last4=Addison |first4=Thomas Kwame |last5=Ibrahim |first5=Mahamat Alhadj Moussa |last6=Weber |first6=Judith Sophie |last7=Kelm |first7=Soerge |last8=Badu |first8=Kingsley |date=2024-06-05 |title=The Transmission of Animal African Trypanosomiasis in Two Districts in the Forest Zone of Ghana |url=https://www.ajtmh.org/view/journals/tpmd/110/6/article-p1127.xml |journal=The American Journal of Tropical Medicine and Hygiene |volume=110 |issue=6 |pages=1127–1136 |doi=10.4269/ajtmh.23-0329 |issn=0002-9637 |pmc=11154048 |pmid=38697074}}</ref>