Amphistomiasis

Symptoms include:

• Physical weakness, emaciation or lethargy{{Cite journal |last1=Huson |first1=Kathryn M. |last2=Oliver |first2=Nicola A. M. |last3=Robinson |first3=Mark W. |date=2017 |title=Paramphistomosis of Ruminants: An Emerging Parasitic Disease in Europe |url=https://pubmed.ncbi.nlm.nih.gov/28754416 |journal=Trends in Parasitology |volume=33 |issue=11 |pages=836–844 |doi=10.1016/j.pt.2017.07.002 |issn=1471-5007 |pmid=28754416|s2cid=3512476 }}{{Citation |last=Chai |first=Jong-Yil |title=Amphistomes |date=2019 |url=http://link.springer.com/10.1007/978-94-024-1704-3_3 |work=Human Intestinal Flukes |pages=345–368 |access-date=2023-03-21 |place=Dordrecht |publisher=Springer Netherlands |language=en |doi=10.1007/978-94-024-1704-3_3 |isbn=978-94-024-1702-9|url-access=subscription }}
• Foul smell of faeces, greasy consistency and scour or diarrhoea
• Anorexia, refusal to eat food{{Cite journal |last1=Ahluwalia |first1=J. S. |last2=Singh |first2=A. N. |date=1975 |title=Treatment of Amphistomiasis in Sheep |url=https://www.jstor.org/stable/24081963 |journal=Current Science |volume=44 |issue=24 |pages=907–908 |issn=0011-3891 |jstor=24081963}}{{Citation |last=Rajkumari |first=Nonika |title=Amphistomiasis |date=2022 |url=https://link.springer.com/10.1007/978-981-16-7204-0_27 |work=Textbook of Parasitic Zoonoses |series=Microbial Zoonoses |pages=293–300 |editor-last=Parija |editor-first=Subhash Chandra |access-date=2023-03-21 |place=Singapore |publisher=Springer Nature Singapore |language=en |doi=10.1007/978-981-16-7204-0_27 |isbn=978-981-16-7203-3 |editor2-last=Chaudhury |editor2-first=Abhijit|url-access=subscription }}
• Dehydration and frequent drinking of water
• Submaxillary oedema (bottle jaw) and pale mucous membrane
• Intestinal bleeding (haemorrhagic enteritis) with anaemia and low blood protein (hypoproteinaemia)
• Damage to the bile duct, and liver cirrhosis
• In humans (specifically gastrodiscoidiasis) symptoms include diarrhoea, fever, abdominal pain, colic, and an increased mucus production. Large amounts of eggs can cause tissue reactions in the heart or mesenteric lymphatics, which may lead to death. Mortality among native Assamese children is attributed to this infection.{{cite journal |vauthors=Mas-Coma S, Bargues MD, Valero MA |year=2006 |title=Gastrodiscoidiasis, a plant-borne zoonotic disease caused by the intestinal amphistome fluke Gastrodiscoides hominis (Trematoda: Gastrodiscidae) |url=http://bibliotecavirtual.ranf.com/i18n/catalogo_imagenes/grupo.cmd?path=1001740 |url-status=dead |journal=Revista Ibérica de Parasitología |volume=66 |issue=1–4 |pages=75–81 |issn=0034-9623 |archive-url=https://web.archive.org/web/20140503155005/http://bibliotecavirtual.ranf.com/i18n/catalogo_imagenes/grupo.cmd?path=1001740 |archive-date=2014-05-03}}

Amphistomiasis in farm and wild mammals is due to infection of paramphistomes, such as the species of Paramphistomum, Calicophoron, Cotylophoron, Pseudophisthodiscus, etc. These are essentially rumen flukes, of which Paramphistomum cervi is the most notorious in terms of prevalence and pathogenicity. Infection occurs through ingestion of contaminated vegetables and raw meat, in which the viable infective metacercaria are deposited from snails, which are the intermediate hosts.{{cite book |vauthors=Bowman DD, Georgi JR |title= Georgis' Parasitology for Veterinarians |publisher=W.B. Saunders Company|url=https://books.google.com/books?id=g_tBWVBevM0C&pg=PA124 |edition=9|page=124|isbn=978-1-4160-4412-3|year= 2009 }}{{cite journal |vauthors=Chai JY, Shin EH, Lee SH, Rim HJ |year=2009|title= Foodborne intestinal flukes in Southeast Asia| journal= The Korean Journal of Parasitology|volume=47|issue=Suppl|pages= 69–102|pmid=19885337 |doi=10.3347/kjp.2009.47.S.S69 |pmc=2769220}} The immature flukes are responsible for destroying the mucosal walls of the alimentary tract on their way to growing into adults. It is by this fervent tissue obliteration that the clinical symptoms are manifested. The adult flukes, on the other hand, are quite harmless, as they merely prepare for reproduction.{{cite book |author = Brown DS|year=2005|title=Freshwater Snails Of Africa And Their Medical Importance| url=https://books.google.com/books?id=1oWJGDaMMHwC|edition=2 |publisher=Taylor & Francis Ltd |pages=366–370 |isbn=978-0-203-48144-8}}

The zoonotic infection in human is caused by G. discoides and W. watsoni which are essentially intestinal flukes. The disease due to G. discoides is more specifically termed gastrodiscoidiasis.{{cite book|author = Liu D|year=2012|title= Molecular Detection of Human Parasitic Pathogens |url= https://books.google.com/books?id=01kmUUnJLScC | publisher= Crc Press, Boca Raton, FL |pages= 365–368 |isbn=978-1-4398-1242-6}} In their natural hosts such as pigs and monkeys, their infection in asymptomatic, but human infection is prevalent, by which they cause serious health problems, characterised by diarrhoea, fever, abdominal pain, colic, and an increased mucous production. In extreme situations such as in Assam, India, a number of mortality among children is attributed to this disease.{{cite journal|vauthors=Mas-Coma S, Bargues MD, Valero MA |year=2006 |title=Gastrodiscoidiasis, a plant-borne zoonotic disease caused by the intestinal amphistome fluke Gastrodiscoides hominis (Trematoda:Gastrodiscidae) |url=http://bibliotecavirtual.ranf.com/i18n/catalogo_imagenes/grupo.cmd?path=1001740 |journal=Revista Ibérica de Parasitología |volume=66 |issue=1–4 |pages=75–81 |issn=0034-9623 |url-status=dead |archive-url=https://web.archive.org/web/20140503155005/http://bibliotecavirtual.ranf.com/i18n/catalogo_imagenes/grupo.cmd?path=1001740 |archive-date=2014-05-03 }}

Adult flukes are known to be quite harmless, as they do not attack on the host tissue. It is the immature flukes which are most damaging as they get attached to the intestinal wall, literally and actively sloughing off of the tissue. This necrosis is indicated by haemorrhage in faeces, which in turn is a sign of severe enteritis. Under such condition the animals become anorexic and lethargic. It is often accompanied by pronounced diarrhoea, dehydration, oedema, polydipsia, anaemia, listlessness and weight loss. In sheep profuse diarrhoea usually develops two to four weeks after initial infection. If infection is not properly attended death can ensue within 20 days, and in a farm mortality can be very high. In fact there are intermittent reports of mortality as high as 80% among sheep and cattle.{{cite journal |vauthors=Vasilev I, Denev I, Savova S, Kostov R, Georgiev B |year=1985|title= Pathogenesis of paramphistomiasis in sheep|journal=Veterinarno-Meditsinski Nauki| volume=22|issue=2|pages= 67–73|pmid=3992928}}{{cite journal |vauthors=Rolfe PF, Boray JC, Collins GH |year=1994|title= Pathology of infection with Paramphistomum ichikawai in sheep|journal=International Journal for Parasitology| volume=24|issue=7|pages= 995–1004|pmid= 7883450|doi=10.1016/0020-7519(94)90165-1}} Sometimes chronic form is also seen with severe emaciation, anaemia, rough coat, mucosal oedema, thickened duodenum and oedema in the sub maxillary space.{{cite journal |vauthors=Singh RP, Sahai BN, Jha GJ |year=1984|title= Histopathology of the duodenum and rumen of goats during experimental infections with Paramphistomum cervi |journal=Veterinary Parasitology| volume=15|issue=1|pages= 39–46|pmid=6541393|doi=10.1016/0304-4017(84)90108-0}}{{cite journal |vauthors=Mavenyengwa M, Mukaratirwa S, Obwolo M, Monrad J |year=2005|title= A macro- and light microscopical study of the pathology of Calicophoron microbothrium infection in experimentally infected cattle|journal=The Onderstepoort Journal of Veterinary Research| volume=72|issue=4|pages= 321–32|pmid=16562736|doi=10.4102/ojvr.v72i4.189|doi-access=free}} The terminally sick animals lie prostrate on the ground, completely emaciated until they die. In buffalos, severe haemorrhage was found to be associated with liver cirrhosis and nodular hepatitis.{{cite journal |vauthors=Ahmedullah F, Akbor M, Haider MG, Hossain MM, Khan M, Hossain MI, Shanta IS |year=2007|title= Pathological investigation of liver of the slaughtered buffaloes in Barisal district|journal= Bangladesh Journal of Veterinary Medicine| volume=5|issue=1–2|pages=81–85|doi= 10.3329/bjvm.v5i1.1321|doi-access=free}}

Under most situations, infection is hard to recognize because the symptoms are mild or even absent. In humans and wild animals, infection is not easily identified. Especially the adult flukes, even if in large number, generally do not cause complications. There is not yet a standard diagnostic test. Therefore, manual diagnosis is done at many levels. Diagnosis basically relies on a combination of postmortem analyses, clinical signs displayed by the animals, and response to drenching. In heavy infection, symptoms are easily observed in sheep and cattle as they become severely anorexic or inefficiently digest food, and become unthrifty. Copious fetid diarrhea is an obvious indication, as the soiling of hind legs and tails with fluid feces are readily noticeable.

Even though it not always the case, immature flukes can be identified from the fluid excrement. On rare occasions, eggs can be identified from stools of suspected animals. In developing countries diagnosis and prognosis is often hindered by multiple infections with other trematodes, such as Fasciola hepatica and schistosomes, because these flukes are given primary importance due to their pervasive nature.

Amphistomiasis is considered a neglected tropical disease, with no prescription drug for treatment and control. Therefore, management of infestation is based mainly on control of the snail population, which transmit the infective larvae of the flukes. However, there are now drugs shown to be effective including resorantel, oxyclozanide, clorsulon, ivermectin, niclosamide, bithional and levamisole.{{cite journal |vauthors=Georgiev B, Gruev A |year=1979|title= Effectiveness of levamisole and oxyclozanide in paramphistomiasis in sheep and cattle|journal=Vet Med Nauki|volume=16|issue=3|pages= 45–51 |pmid=524749}}{{cite journal |vauthors=Rolfe PF, Boray JC |year=1987|title= Chemotherapy of paramphistomosis in cattle|journal=Australian Veterinary Journal|volume=64|issue=11|pages= 328–332|pmid=3447575|doi=10.1111/j.1751-0813.1987.tb06060.x}}{{cite journal |vauthors=Rolfe PF, Boray JC |year=1988|title= Chemotherapy of paramphistomosis in sheep|journal=Australian Veterinary Journal|volume=65|issue=5|pages= 148–150|pmid=3401161|doi=10.1111/j.1751-0813.1988.tb14443.x }} An in vitro demonstration shows that plumbagin exhibits high efficacy on adult flukes.{{cite journal |vauthors=Saowakon N, Lorsuwannarat N, Changklungmoa N, Wanichanon C, Sobhon P |year=2013|title= Paramphistomum cervi: the in vitro effect of plumbagin on motility, survival and tegument structure|journal=Experimental Parasitology|volume=133|issue=2|pages= 179–186|pmid=23206952|doi=10.1016/j.exppara.2012.11.018}}{{cite journal |vauthors=Katiyar RD, Garg RK |year=1965|title= Comparative efficacy of various chemotherapeutic agents in amphistomiasis |journal= Advances in Parasitology |volume=42|issue=10 |pages= 761–768|pmid=5892245}}

Since the juvenile flukes are the causative individuals of the disease, effective treatment means control of the immature fluke population. Prophylaxis is therefore based on disruption of the environment (such as proper drainage) where the carrier snails inhabit, or more drastic action of using molluscicides to eradicate the entire population. For treatment of the infection, drugs effective against the immature flukes are recommended for drenching. For this reason oxyclozanide is advocated as the drug of choice. It effectively kills the flukes within a few hours and it effective against the flukes resistant to other drugs. The commercially prescribed dosage is 5 mg/kg body weight or 18.7 mg/kg body weight in two divided dose within 72 hours.{{cite journal |vauthors=Mereminskiĭ AI, ((Gluzman IIa)) |year=1979|title= Prognosis and prevention of fascioliasis and paramphistomiasis |journal= Veterinariia|volume=7|issue=1 |pages= 43–45|pmid= 543077}} Niclosamide is also extensively used in mass drenching of sheep. Successfully treated sheep regain appetite within a week, diarrhoea stops in about three days, and physiological indicators (such as plasma protein and albumin levels) return to normal in a month.

{{Reflist}}

• [https://web.archive.org/web/20130320132821/http://www.veterinarytechinfo.com/amphistomiasis-paramphistomiasis-in-cattle/ Veterinary Technical Information]
• [https://web.archive.org/web/20181003101348/http://www.poulvet.com/vetproducts/medicine_detail.php?mediid=437 Drug information at Poulvet]
• [https://web.archive.org/web/20171214195844/http://www.medivetah.com/cattle/adzanide.php Drug information at Medivet Pharmaceuticals Lab Pvt Ltd]
• [http://www.pvsanimalhealth.com/Veterinary.aspx Drug information at PVS Animal Health]
• [http://merial.co.nz/Sheep/DiseaseInformation/Pages/paramp.aspx Disease information at Merial Sanofi]

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Category:Parasitic diseases

Category:Helminthiases

Category:Tropical diseases