Editing Fasciola hepatica (section)

== Life cycle ==
[[File:Galba truncatula shell.png|thumb|''[[Galba truncatula]]'', an amphibious freshwater [[Lymnaeidae|lymnaeid snail]] that serves as the main intermediate host of ''Fasciola hepatica'' in Europe]]
[[File:Fasciola LifeCycle 2013.png|thumb|The lifecycle of ''Fasciola hepatica'']]

''Fasciola hepatica'' occurs in the [[liver]] and [[bile ducts]] of a [[definitive host]] and its lifecycle is indirect. Definitive hosts of the [[Trematoda|fluke]] are [[cattle]], [[sheep]] and [[goat]]s as well as [[water buffalo]].<ref>{{cite journal|last1=El-Tahawy|first1=A.S.|last2=Kwan|first2=N.|last3=Sugiura|first3=K.|title=''Fasciola hepatica'' infection in water buffalo ''Bubalus bubalis'' in three provinces of the Nile Delta, Egypt: a cross-sectional study|journal=The Journal of Veterinary Medical Science|volume=80|issue=1|year=2017|pages=28–35|pmid=29151443|pmc=5797855|doi=10.1292/jvms.17-0282|doi-access=free}}</ref>  Wild [[ruminant]]s, such as [[African buffalo]],<ref>{{cite journal|last=Bindernagel|first=J.A.|year=1972|title=LIVER FLUKE ''Fasciola gigantica'' IN AFRICAN BUFFALO AND ANTELOPES IN UGANDA, EAST AFRICA|journal=Journal of Wildlife Diseases|volume=8|issue=4|pages=315–317|doi=10.7589/0090-3558-8.4.315|doi-access=free|pmid=4673717 }}</ref> and other mammals, including humans, can act as definitive hosts as well.<ref name="torgerson_claxton">{{cite book |last= Torgerson |first=P |author2= Claxton JR |chapter=Epidemiology and Control |editor=Dalton, JP |title=Fasciolosis |publisher=CABI Pub |location=Wallingford, Oxon, UK |year=1999 |pages=113–149 |isbn=978-0-85199-260-0 }}</ref> Rabbits and hares can serve as wild life [[Natural_reservoir|reservoirs]]. <ref name="Davis 2020">{{cite journal |last1=Davis |first1=C.N. |last2=Tyson |first2=F. |last3=Cutress |first3=D. |last4=Davies |first4=E. |last5=Jones |first5=D.L. |last6=Brophy |first6=P.M. |last7=Prescott |first7=A. |last8=Rose |first8=M.T. |last9=Williams |first9=M. |last10=Williams |first10=H.W. |last11=Jones |first11=R.A. |title=Rapid detection of <i>Galba truncatula</i> in water sources on pasture-land using loop-mediated isothermal amplification for control of trematode infections |journal=Parasites & Vectors |date=2020 |volume=13 |issue=1 |doi=10.1186/s13071-020-04371-0|doi-access=free |hdl=2160/52a918f4-b870-45b1-bb07-19b6510faf14 |hdl-access=free }}</ref> The life cycle of ''F.&nbsp;hepatica'' goes through the [[intermediate host]] and several environmental larval stages.<ref name="andrews">{{cite book |last= Andrews |first=JS |chapter= Life cycle of Fasciola hepatica |editor=Dalton, JP |title=Fasciolosis |publisher=CABI Pub |location=Wallingford, Oxon, UK |year=1999 |pages=1–30 |isbn=978-0-85199-260-0 }}</ref> Intermediate hosts of ''F.&nbsp;hepatica'' are air-breathing freshwater snails from the family [[Lymnaeidae]]. Although several lymnaeid species susceptible to ''F.&nbsp;hepatica'' have been described, the parasite develops only in one or two major species on each continent. ''[[Galba truncatula]]'' is the main snail host in Europe, partly in Asia, Africa, and South America. ''[[Lymnaea viatrix|Lymnaea viator]]'', ''[[Lymnaea neotropica|L.&nbsp;neotropica]]'', ''[[Pseudosuccinea columella]]'', and ''[[Lymnaea cubensis|L.&nbsp;cubensis]]'' are most common intermediate hosts in Central and South America.<ref name="Mas‐ComaValero2009" /><ref>{{cite journal |last1=Bargues |first1=M. D. |last2=Gayo |first2=V. |last3=Sanchis |first3=J. |last4=Artigas |first4=P. |last5=Khoubbane |first5=M. |last6=Birriel |first6=S. |last7=Mas-Coma |first7=S. |date=2017 |title=DNA multigene characterization of Fasciola hepatica and Lymnaea neotropica and its fascioliasis transmission capacity in Uruguay, with historical correlation, human report review and infection risk analysis |journal=PLOS Neglected Tropical Diseases |volume=11 |issue=2 |pages= e0005352| pmid=28158188 | doi=10.1371/journal.pntd.0005352|pmc=5310921 | doi-access=free}}</ref><ref name="torgerson_claxton" /> Several other lymnaeid snails may be naturally or experimentally infected with ''F.&nbsp;hepatica'', but their role in transmission of the fluke is low.<ref name="Mas‐ComaValero2009" /> The list of lymnaeid snails that may serve as natural or experimental intermediate hosts of ''F.&nbsp;hepatica'' include:<ref name="Correa 2010">{{cite journal | last1 = Correa | first1 = C. A. | last2 = Escobar | first2 = J. S. | last3 = Durand | first3 = P. | last4 = Renaud | first4 = F. | last5 = David | first5 = P. | last6 = Jarne | first6 = P. | last7 = Pointier | first7 = J.-P. | last8 = Hurtrez-Boussès | first8 = S. | year = 2010 | title = Bridging gaps in the molecular phylogeny of the Lymnaeidae (Gastropoda: Pulmonata), vectors of Fascioliasis | journal = [[BMC Evolutionary Biology]] | volume = 10 | issue = 1 | page = 381 | doi = 10.1186/1471-2148-10-381 | pmid=21143890 | pmc=3013105 | doi-access = free | bibcode = 2010BMCEE..10..381C }}</ref>

* ''[[Austropeplea ollula]]''
* ''[[Austropeplea tomentosa]]''
* ''[[Austropeplea viridis]]''
* ''[[Fossaria bulimoides]]''
* ''[[Galba truncatula]]''
* ''[[Lymnaea cousini]]''
* ''[[Lymnaea cubensis]]''
* ''[[Lymnaea diaphana]]''
* ''[[Lymnaea humilis]]''
* ''[[Lymnaea neotropica]]''
* ''[[Lymnaea occulta]]''
* ''[[Lymnaea stagnalis]]''
* ''[[Lymnaea viatrix]]''
* ''[[Omphiscola glabra]]''
* ''[[Pseudosuccinea columella]]''
* ''[[Radix auricularia]]''
* ''[[Radix lagotis]]''
* ''[[Radix natalensis]]''
* ''[[Radix peregra]]''
* ''[[Radix rubiginosa]]''
* ''[[Stagnicola caperata]]''
* ''[[Stagnicola fuscus]]''
* ''[[Stagnicola palustris]]''
* ''[[Stagnicola turricula]]''

The [[metacercariae]] are released from the [[freshwater snail]] as [[cercariae]], and form cysts on various surfaces including [[Aquatic plant|aquatic vegetation]]. The [[mammal]]ian host then eats this vegetation and can become infected. Humans can often acquire these infections through drinking contaminated water and eating freshwater [[plants]] such as [[watercress]]. Inside the [[duodenum]] of the mammalian host, the metacercariae are released from within their cysts. From the duodenum, they burrow through the lining of the [[intestine]] and into the [[peritoneal cavity]]. They then migrate through the intestines and liver, and into the bile ducts. Inside the bile ducts, they develop into an adult fluke.<ref name="CDCfascioliasis">{{cite web|title=Liver Flukes: About Fasciola|url=https://www.cdc.gov/liver-flukes/fasciola/index.html|website=cdc.gov|access-date=19 January 2025|date=14 February 2024}}</ref><ref>{{cite web|url=https://www.cdc.gov/dpdx/fascioliasis/index.html|title=Fascioliasis|website=DPDx - Laboratory Identification of Parasites of Public Health Concern|publisher=U.S. Centers for Disease Control and Prevention|access-date=19 January 2025|date=2 May 2019|author=((National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Parasitic Diseases and Malaria))}}</ref> In humans, the time taken for ''F.&nbsp;hepatica'' to mature from metacercariae into an adult fluke is roughly three to four months. The adult flukes can then produce up to 25,000 eggs per fluke per day.<ref>{{cite journal |last1=Valero |first1=M. Adela |last2=Panova |first2=Miroslava |last3=Comes |first3=Ana M. |last4=Fons |first4=Roger |last5=Mas-Coma |first5=Santiago |title=Patterns in size and shedding of Fasciola hepatica eggs by naturally and experimentally infected murid rodents |journal=Journal of Parasitology |date=April 2002 |volume=88 |issue=2 |pages=308–313 |doi=10.1645/0022-3395(2002)088[0308:PISASO]2.0.CO;2 |pmid=12054003 |hdl=10550/16781 |s2cid=41190159 |hdl-access=free }}</ref> These eggs are passed out via [[Feces|stools]] and into freshwater. Once in freshwater, the eggs become [[embryonated]], allowing them to hatch as [[miracidia]], which then find a suitable intermediate snail host of the [[Lymnaeidae]] family. Inside this snail, the miracidia develop into [[Trematode lifecycle stages|sporocysts]], then to [[Trematode life cycle stages|rediae]], then to cercariae. The cercariae are released from the snail to form metacercariae and the life cycle begins again.<ref name="CDCfascioliasis"/>