Fasciola gigantica

Fasciola gigantica
	Cobbold's drawings of dorsal (left) and ventral views of Fasciola gigantica
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Platyhelminthes
Class:	Trematoda
Order:	Plagiorchiida
Family:	Fasciolidae
Genus:	Fasciola
Species:	F. gigantica
Binomial name
	Fasciola gigantica; Cobbold, 1855

Last updated March 16, 2024

Fasciola gigantica is a parasitic flatworm of the class Trematoda, which causes tropical fascioliasis. It is regarded as one of the most important single platyhelminth infections of ruminants in Asia and Africa. The infection is commonly called fasciolosis.

The prevalence of F. gigantica often overlaps with that of Fasciola hepatica , and the two species are so closely related in terms of genetics, behaviour, and morphological and anatomical structures that distinguishing them is notoriously difficult.^[2] Therefore, sophisticated molecular techniques are required to correctly identify and diagnose the infection.^[3]

Distribution

Fasciola gigantica causes outbreaks in tropical areas of South Asia, Southeast Asia, and Africa. The geographical distribution of F. gigantica overlaps with F. hepatica in many African and Asian countries and sometimes in the same country, although in such cases, the ecological requirement of the flukes and their snail hosts are distinct. Infection is most prevalent in regions with intensive sheep and cattle production. In Egypt, F. gigantica has existed in domestic animals since the times of the pharaohs.^[4]

Lifecycle

The lifecycle of F. gigantica is: Eggs (transported with feces) → egg hatch → miracidium → miracidium infect snail intermediate host → (parthenogenesis in 24 hours) sporocyst → redia → daughter redia → cercaria → (gets outside the snail) → metacercaria → infection of the host → adult stage produces eggs.

Intermediate hosts

As with other trematodes, Fasciola spp. develop in a molluscan intermediate host. Species of the freshwater snails from the family Lymnaeidae are well known for their role as intermediate hosts in the lifecycle of F. gigantica; however, throughout the years, an increasing number of other molluscan intermediate hosts of F. gigantica have been reported.^[4] The lymnaeid intermediate hosts of F. gigantica are distinguishable from those of F. hepatica, both morphologically and as to habitat requirement. The species of Fasciola can become adapted to new intermediate hosts under certain conditions at least based on laboratory trials. The most important intermediate host for F. gigantica is Radix auricularia . However, other species are also known to harbour the fluke, including Lymnaea rufescens and Lymnaea acuminata in the Indian subcontinent; Radix rubiginosa and Radix natalensis in Malaysia and Africa, respectively; and the synonymous Lymnaea cailliaudi in East Africa. Other snails also serve as natural or experimental intermediates, such as Austropeplea ollula , Austropeplea viridis , Radix peregra , Radix luteola , Pseudosuccinea columella , and Galba truncatula .^[5]^[6] The Australian Lymnaea tomentosa (host of F. hepatica) was shown to be receptive to miracidia of F. gigantica from East Africa, Malaysia, and Indonesia.^[4]

Definitive hosts

F. gigantica is a causative agent (together with F. hepatica) of fascioliasis in ruminants and in humans worldwide.^[4]

The parasite commonly infects cattle and buffalo, and can also be seen regionally in goats and sheep, and in nonruminants (donkeys).

Infection and pathogenicity

Infection with Fasciola spp. occurs when metacercariae are accidentally ingested on raw vegetation. The metacercariae exist in the small intestine, and move through the intestinal wall and peritoneal cavity to the liver, where adults mature in the biliary ducts of the liver. Eggs are passed through the bile ducts into the intestine, where they are then passed in the feces.^[4]

Diagnosis

Despite the importance to differentiate between the infection by either fasciolid species, due to their distinct epidemiological, pathological, and control characteristics, unfortunately, coprological (excretion-related) or immunological diagnoses are difficult. Especially in humans, specific detection by clinical, pathological, coprological, or immunological methods are unreliable. Molecular assays are the only promising tools, such as PCR-RFLP assay,^[3]^[7] and the very rapid loop-mediated isothermal amplification (LAMP).^[8]

Treatment

Triclabendazole is the drug of choice in fasciolosis, as it is highly effective against both mature and immature flukes. Artemether has been demonstrated in vitro to be equally effective.^[9] Though slightly less potent, artesunate is also useful in human fasciolosis.^[10]

Related Research Articles

Trematoda is a class of flatworms known as flukes or trematodes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five traditional vertebrate classes: mammals, birds, amphibians, reptiles, and fish.

Fasciolosis is a parasitic worm infection caused by the common liver fluke Fasciola hepatica as well as by Fasciola gigantica. The disease is a plant-borne trematode zoonosis, and is classified as a neglected tropical disease (NTD). It affects humans, but its main host is ruminants such as cattle and sheep. The disease progresses through four distinct phases; an initial incubation phase of between a few days up to three months with little or no symptoms; an invasive or acute phase which may manifest with: fever, malaise, abdominal pain, gastrointestinal symptoms, urticaria, anemia, jaundice, and respiratory symptoms. The disease later progresses to a latent phase with less symptoms and ultimately into a chronic or obstructive phase months to years later. In the chronic state the disease causes inflammation of the bile ducts, gall bladder and may cause gall stones as well as fibrosis. While chronic inflammation is connected to increased cancer rates, it is unclear whether fasciolosis is associated with increased cancer risk.

Fasciolopsiasis results from an infection by the trematode Fasciolopsis buski, the largest intestinal fluke of humans, growing up to 7.5 cm (3.0 in) long.

Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic trematode of the class Trematoda, phylum Platyhelminthes. It infects the livers of various mammals, including humans, and is transmitted by sheep and cattle to humans all over the world. The disease caused by the fluke is called fasciolosis or fascioliasis, which is a type of helminthiasis and has been classified as a neglected tropical disease. Fasciolosis is currently classified as a plant/food-borne trematode infection, often acquired through eating the parasite's metacercariae encysted on plants. F. hepatica, which is distributed worldwide, has been known as an important parasite of sheep and cattle for decades and causes significant economic losses in these livestock species, up to £23 million in the UK alone. Because of its relatively large size and economic importance, it has been the subject of many scientific investigations and may be the best-known of any trematode species. F. hepatica's closest relative is Fasciola gigantica. These two flukes are sister species; they share many morphological features and can mate with each other.

Fasciola, commonly known as the liver fluke, is a genus of parasitic trematodes. There are three species within the genus Fasciola: Fasciola nyanzae,Fasciolahepatica and Fasciolagigantica. Fasciola hepatica and F. gigantica are known to form hybrids. Both F. hepatica and F. gigantica and their hybrids infect the liver tissue of a wide variety of mammals, including humans, in a condition known as fascioliasis. F. hepatica measures up to 30 mm by 15 mm, while F. gigantica measures up to 75 mm by 15 mm. Fasciola nyanzae is thought to exclusively infect the common hippopotamus, Hippopotamus amphibius.

Fascioloides magna, also known as giant liver fluke, large American liver fluke or deer fluke, is trematode parasite that occurs in wild and domestic ruminants in North America and Europe. Adult flukes occur in the liver of the definitive host and feed on blood. Mature flukes measure 4 to 10 centimetres in length × 2 to 3.5 centimetres in width, and have an oval dorso-ventrally flattened body with oral and ventral sucker. The flukes are reddish-brown in colour and are covered by tegument. As with other digenean trematodes, the life cycle includes intramolluscan phase in snails. The parasite is currently distributed in wild ruminants in North America and Europe, including Austria, Canada, the Czech Republic, Croatia, Germany, Hungary, Italy, Poland, Serbia, Slovakia, and the United States.

Galba truncatula is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.

Liver fluke is a collective name of a polyphyletic group of parasitic trematodes under the phylum Platyhelminthes. They are principally parasites of the liver of various mammals, including humans. Capable of moving along the blood circulation, they can occur also in bile ducts, gallbladder, and liver parenchyma. In these organs, they produce pathological lesions leading to parasitic diseases. They have complex life cycles requiring two or three different hosts, with free-living larval stages in water.

Lymnaea tomentosa is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.

Radix is a genus of air-breathing freshwater snails, aquatic pulmonate gastropods in the family Lymnaeidae, the pond snails.

Pseudosuccinea columella, the American ribbed fluke snail, is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.

Radix auricularia, the big-ear radix, is a species of medium-sized freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae.

Fasciolopsis is a genus of trematodes. They are also known as giant intestinal flukes.

Austropeplea ollula is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.

Echinostoma revolutum is a trematode parasite of which the adults can infect birds and mammals, including humans. In humans, it causes echinostomiasis.

Radix luteola is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.

Radix natalensis is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.

Galba neotropica is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.

Austropeplea viridis is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.

Gastropod-borne parasitic diseases (GPDs) are a group of infectious diseases that require a gastropod species to serve as an intermediate host for a parasitic organism that can infect humans upon ingesting the parasite or coming into contact with contaminated water sources. These diseases can cause a range of symptoms, from mild discomfort to severe, life-threatening conditions, with them being prevalent in many parts of the world, particularly in developing regions. Preventive measures such as proper sanitation and hygiene practices, avoiding contact with infected gastropods and cooking or boiling food properly can help to reduce the risk of these diseases.

References

This article incorporates CC-BY-3.0 text from references.^[4]^[11]

↑ Cobbold, T. S. (1855). Description of a new trematode worm (Fasciola gigantica). The Edinburgh New Philosophical Journal, Exhibiting a View of the Progressive Discoveries and Improvements in the Sciences and the Arts. New Series, II, 262–267.
↑ Itagaki T, Ichinomiya M, Fukuda K, Fusyuku S, Carmona C (2011). "Hybridization experiments indicate incomplete reproductive isolating mechanism between Fasciola hepatica and Fasciola gigantica". Parasitology. 138 (10): 1278–1284. doi:10.1017/S0031182011000965. PMID 21767436.
1 2 Rokni MB, Mirhendi H, Mizani A, Mohebali M, Sharbatkhori M, Kia EB, Abdoli H, Izadi S (2010). "Identification and differentiation of Fasciola hepatica and Fasciola gigantica using a simple PCR-restriction enzyme method". Experimental Parasitology . 124 (2): 209–213. doi:10.1016/j.exppara.2009.09.015. PMID 19769969.
1 2 3 4 5 6 Soliman, MF (1 June 2008). "Epidemiological review of human and animal fascioliasis in Egypt". Journal of Infection in Developing Countries . 2 (3): 182–9. doi: 10.3855/jidc.260 . PMID 19738348.
↑ Correa AC, Escobar JS, Durand P, Renaud F, David P, Jarne P, Pointier JP, Hurtrez-Boussès S (2010). "Bridging gaps in the molecular phylogeny of the Lymnaeidae (Gastropoda: Pulmonata), vectors of Fascioliasis". BMC Evolutionary Biology. 10: 381. doi: 10.1186/1471-2148-10-381 . PMC 3013105 . PMID 21143890.
↑ Dar YD, Rondelaud D, Dreyfuss G (2005). "Update of fasciolosis-transmitting snails in Egypt (review and comment)". Journal of the Egyptian Society of Parasitology. 35 (2): 477–490. PMID 16083061.
↑ El-Rahimy HH, Mahgoub AM, El-Gebaly NS, Mousa WM, Antably AS (2012). "Molecular, biochemical, and morphometric characterization of Fasciola species potentially causing zoonotic disease in Egypt". Parasitology Research. 111 (3): 1103–111. doi:10.1007/s00436-012-2938-2. PMID 22638917.
↑ Ai L, Li C, Elsheikha HM, Hong SJ, Chen JX, Chen SH, Li X, Cai XQ, Chen MX, Zhu XQ (2010). "Rapid identification and differentiation of Fasciola hepatica and Fasciola gigantica by a loop-mediated isothermal amplification (LAMP) assay". Veterinary Parasitology. 174 (3–4): 228–233. doi:10.1016/j.vetpar.2010.09.005. PMID 20933335.
↑ Shalaby HA, El Namaky AH, Kamel RO (2009). "In vitro effect of artemether and triclabendazole on adult Fasciola gigantica". Veterinary Parasitology. 160 (1–2): 76–82. doi:10.1016/j.vetpar.2008.10.027. PMID 19036519.
↑ Hien TT, Truong NT, Minh NH, Dat HD, Dung NT, Hue NT, Dung TK, Tuan PQ, Campbell JI, Farrar JJ, Day JN (2008). "A randomized controlled pilot study of artesunate versus triclabendazole for human fascioliasis in central Vietnam". American Journal of Tropical Medicine and Hygiene. 78 (3): 388–392. PMID 18337331.
↑ Onocha P. & Otunla E. (2008). "Biological activities of extracts of Pycnanthus angolensis (Welw.) Warb". African Journal of Traditional, Complementary and Alternative medicines, Abstracts of the world congress on medicinal and aromatic plants, Cape Town, November 2008. abstract Archived 2012-03-12 at the Wayback Machine