Heterophyes heterophyes | |
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Adult specimen stained with carmine | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Platyhelminthes |
Class: | Trematoda |
Order: | Plagiorchiida |
Family: | Heterophyidae |
Genus: | Heterophyes |
Species: | H. heterophyes |
Binomial name | |
Heterophyes heterophyes (Siebold, 1853) | |
Synonyms | |
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Heterophyes heterophyes, or the intestinal fish fluke, was discovered by Theodor Maximaillian Bilharz in 1851. This parasite was found during an autopsy of an Egyptian mummy. [1] H. heterophyes is found in the Middle East, West Europe and Africa. [2] They use different species to complete their complex lifestyle. Humans and other mammals are the definitive host, first intermediate host are snails, and second intermediate are fish. Mammals that come in contact with the parasite are dogs, humans, and cats. Snails that are affected by this parasite are the Cerithideopsilla conica . Fish that come in contact with this parasite are Mugil cephalus, Tilapia milotica, Aphanius fasciatus, and Acanthgobius sp. [2] Humans and mammals will come in contact with this parasite by the consumption of contaminated or raw fish. [3] This parasite is one of the smallest endoparasite to infect humans. [4] It can cause intestinal infection called heterophyiasis. [5]
This species occurs in Egypt, Sudan, Israel, Brazil, Spain, Turkey, Iran, India, and Russia. [6] Common in North Africa, Asia Minor, Korea, China, Japan, Taiwan, and the Philippines. In Egypt, after looking at twelve populations of Cerithideopsilla conica , which is mud snail and carrier of Heterophyes heterophyes, it was found that the most infected snails were found in the Nile Delta compared to the Red sea coast and inland waters of the Delta. [7] The transmission of Heterophyes heterophyes from, Pirenella conica, a snail, to fish which live in Northern Africa in lagoons that are connected to the sea. For transmission to occur from snails to fish the snails had to be larger than 5 mm. [8]
Minute teardrop-shaped flukes found in the small intestines of fish-eating birds and mammals. The eggs are hard to tell apart from other related species so there is no accurate estimate of human infection. H. heterophyes is a small trematode, ranging up to 1.4mm long and 0.5mm wide. [4] It is covered with scale-like spikes and those spikes can range from 50–62. [9] Their pharynx is completely developed and connected to the cecum of the small intestines. Their sucker (mouth) is covered with spikes and its covering the genital opening. This means, they share one hole for eating and reproduction. Their testes is located at the posterior of the parasite and the testes are side by side. [4] The ovaries are located in the medial of the parasite, right above the testes. [4] The ventral sucker also known as the acetabulum is located at the ventral of the parasite. [4] The ventral sucker helps them attach to the host. Morphology can change depending on what fish it lives on.
The adult flukes live burrowed between the villi of the host's small intestine. It only takes around 4 to 6 hours for H. heterophyes to get to the small intestines in the definitive host and even faster in hosts that it does not prefer. [10] The eggs that are laid contain a miracidium but do not hatch until they are ingested by a snail (Cerithideopsilla conica [6] in Egypt or Cerithidia cingula [ citation needed ] in Japan). Inside the snails gut, the miracidium becomes a sporocyst which then begin to produce rediae. The rediae produce cercariae which then exit the snail, swim toward the surface of the water, and slowly fall back down. On their way down, they contact a fish and penetrate into the epithelium of the fish. Here, the cercariae encyst in the muscle tissue. The second intermediate host include freshwater fish: Mugil cephalus , Tilapia nilotica , Aphanius fasciatus , and Acanthogobius sp. [6] The definitive host, such as humans or birds, eats the undercooked or raw meat of a fish and ingest the parasite. Natural definitive hosts are cats, dogs, foxes, wolves, pelicans, and humans. [6]
People at high risk for infection are those who live by bay waters including fishermen. Infection is acquired by eating raw fish, a common food in areas of heavy endemicity. In endemic areas, people who live near lake shores or river banks usually have a higher rate and intensity of infection than those living a distance from such areas. It is possible that inhabitants of these areas eat more low-salted or improperly cooked fish and that their fish are obtained from polluted water. It is common practice for people to defecate on the lake shores and river banks or from their boats while fishing. In rural areas of Egypt there was a higher chance of being infected with H. heterophyes due to being a lower socioeconomic area and not having easy access to medical services. [11]
Each worm causes a mild inflammatory reaction at its site of contact with the intestine. In heavy infections which are common cause damage to the mucosa and produce intestinal pain and mucosa diarrhea. Sometimes eggs can enter the blood and lymph vascular systems through mucosa go into the ectopic sites in the body. The heart can be affected with tissue reaction in the valves and myocardium that cause heart failure. Eggs can also get into the brain or spinal cord and cause neurological disorders and sometimes fatalities. Antigen and immune complex deposits left by H. heterophyes in the brain and kidneys of mice prove that there are changes in these tissues of the infected. [12]
H. heterophyes can cause intestinal infection called heterophyiasis. The infection can be asymptomatic or intestinal discomfort and mucous diarrhea. [13] This parasite can start cell apoptosis in the intestinal epithelial cell, at early infection. This infection can cause enlarged intestinal crypts, acute to chronic inflammation, atrophy, and fusion and shortening of the intestinal villi. [13] After early infection this parasite will inhibit apoptosis which can cause the decrease in caspase-3 and NF-jB. Caspase-3 and NF-jB are protein that are essential to induce programmed cell death, apoptosis. [13]
Diagnosis done by stool examination is difficult when adult worms are not present because the eggs are hard to distinguish from C. sinensis.
Praziquantel, a quinolone derivative. The effect of praziquantel on H. heterophyes causes deep lesions on their teguments, and when exposed to praziquantel over a longer period of time leads to even deeper lesions. [14]
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.
Clonorchis sinensis, the Chinese liver fluke, is a liver fluke belonging to the class Trematoda, phylum Platyhelminthes. It infects fish-eating mammals, including humans. In humans, it infects the common bile duct and gall bladder, feeding on bile. It was discovered by British physician James McConnell at the Medical College Hospital in Calcutta (Kolkata) in 1874. The first description was given by Thomas Spencer Cobbold, who named it Distoma sinense. The fluke passes its lifecycle in three different hosts, namely freshwater snail as first intermediate hosts, freshwater fish as second intermediate host, and mammals as definitive hosts.
Metagonimiasis is a disease caused by an intestinal trematode, most commonly Metagonimus yokagawai, but sometimes by M. takashii or M. miyatai. The metagonimiasis-causing flukes are one of two minute flukes called the heterophyids. Metagonimiasis was described by Katsurasa in 1911–1913 when he first observed eggs of M. yokagawai in feces. M. takahashii was described later first by Suzuki in 1930 and then M. miyatai was described in 1984 by Saito.
Opisthorchis viverrini, common name Southeast Asian liver fluke, is a food-borne trematode parasite from the family Opisthorchiidae that infects the bile duct. People are infected after eating raw or undercooked fish. Infection with the parasite is called opisthorchiasis. O. viverrini infection also increases the risk of cholangiocarcinoma, a cancer of the bile ducts.
Echinostoma is a genus of trematodes (flukes), which can infect both humans and other animals. These intestinal flukes have a three-host life cycle with snails or other aquatic organisms as intermediate hosts, and a variety of animals, including humans, as their definitive hosts.
Paragonimiasis is a food-borne parasitic disease caused by several species of lung flukes belonging to genus Paragonimus. Infection is acquired by eating crustaceans such as crabs and crayfishes which host the infective forms called metacercariae, or by eating raw or undercooked meat of mammals harboring the metacercariae from crustaceans.
Opisthorchis felineus, the Siberian liver fluke or cat liver fluke, is a trematode parasite that infects the liver in mammals. It was first discovered in 1884 in a cat's liver by Sebastiano Rivolta of Italy. In 1891, Russian parasitologist, Konstantin Nikolaevich Vinogradov (1847–1906) found it in a human, and named the parasite a "Siberian liver fluke". In the 1930s, helminthologist Hans Vogel of Hamburg published an article describing the life cycle of Opisthorchis felineus. Felineus infections may also involve the pancreatic ducts. Diagnosis of Opisthorchis infection is based on microscopic identification of parasite eggs in stool specimens. Safe and effective medication is available to treat Opisthorchis infections. Adequately freezing or cooking fish will kill the parasite.
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.
Nanophyetus salmincola is a food-borne intestinal trematode parasite prevalent on the Pacific Northwest coast. The species may be the most common trematode endemic to the United States.
Echinostoma revolutum is a trematode parasites, of which the adults can infect birds and mammals, including humans. In humans, it causes echinostomiasis.
Echinostoma hortense is an intestinal fluke of the class Trematoda, which has been found to infect humans in East Asian countries such as Korea, China, and Japan. This parasite resides in the intestines of birds, rats and other mammals such as humans. While human infections are very rare in other regions of the world, East Asian countries have reported human infections up to about 24% of the population in some endemic sub-regions. E. hortense infections are zoonotic infections, which occurs from eating raw or undercooked freshwater fish. The primary disease associated with an E. hortense infection is called echinostomiasis, which is a general name given to diseases caused by Trematodes of the genus Echinostoma.
Cerithideopsilla conica is a species of small sea snail, a marine gastropod mollusk in the family Potamididae.
Haplorchis taichui is a species of intestinal fluke in the family Heterophyidae. It is a human parasite.
Paramphistomum cervi, the type species of Paramphistomum, is a parasitic flat worm belonging to the class Trematoda. It is a tiny fluke mostly parasitising livestock ruminants, as well as some wild mammals. Uniquely, unlike most parasites, the adult worms are relatively harmless, but it is the developing juveniles that cause serious disease called paramphistomiasis, especially in cattle and sheep. Its symptoms include profuse diarrhoea, anaemia, lethargy, and often result in death if untreated.
Echinostoma caproni is a species of 37-spined Egyptian echinostome. It is naturally found in Cameroon, Congo, Egypt, Madagascar, and Togo.
Metagonimus yokogawai, or the Yokogawa fluke, is a species of a trematode, or fluke worm, in the family Heterophyidae.
Metagonimus miyatai is a species of a trematode, or fluke worm, in the family Heterophyidae.
Heterophyes nocens is a species of trematodes, or fluke worms, in the family Heterophyidae.
Trematodiasis is a group of parasitic infections due different species of flukes, the trematodes. Symptoms can range from mild to severe depending on the species, number and location of trematodes in the infected organism. Symptoms depend on type of trematode present, and include chest and abdominal pain, high temperature, digestion issues, cough and shortness of breath, diarrhoea and change in appetite.
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.