| Brachylaima | |
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Platyhelminthes |
| Class: | Trematoda |
| Order: | Diplostomida |
| Family: | Brachylaimidae |
| Genus: | Brachylaima Dujardin, 1843 |
| Species | |
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Brachylaima is a genus of trematodes that can infect the gastrointestinal tract of human beings.
The first documented case of Brachylaima infestation (known as brachylaimiasis) in a human was in 1996, with 8 subsequent cases in the next 4 years. Diagnosis has spread from Australia to other parts of the world, such as the Spanish cities of Barcelona, Bilbao, Madrid, Tudela, Valencia, and Zaragoza. [1] In 2020, it was reported that snails in France were also infected by metacercariae of two species of Brachylaima. [2] Moreover, a study in 2022, from the United Kingdom identified three Brachylaima ( Brachylaima arcuate, B. fuscata and B. mesostoma ) were present in wild terrestrial gastropod species in the city of Nottingham. [3]
Transmission occurs via the ingestion of infected undercooked (or raw) terrestrial gastropods, such as Cornu aspersum (Pulmonata: Stylommatophora). Gastropods act as both the first and second intermediate host in the terrestrial life cycle of Brachylaima species. The first intermediate host harbors asexual sporocysts and produces cercaria through their mucus glands to infect other gastropods via skin to skin contact. The second intermediate host harbors unencysted metacercariae in their kidneys (e.g. Cochlicella acuta , Cernuella virgata and Theba pisana ). Definitive hosts of this species include various species of amphibians, birds, mammals and reptiles. [4] It was first believed that the infection of humans was from children who had purposely eaten the snails, and adults have accidentally ingested snails on vegetables and become infected. [5] Though this may be the case in some parts of the world, it has been shown that humans actively ingest these snails as a source of food in some areas. One study showed that the Spanish city of Tudela had a very high prevalence of the parasite in the snails that were sold as food, though this prevalence fluctuates throughout the year, with the peak season being autumn. This prevalence has become a public concern in many Spanish countries due to the spread of brachylaimiasis. Eggs of this species can remain viable in feces/soil for up to twelve months. The sporocyst infection is 7–10 weeks after the eggs have been ingested.
Clinical features have varied from recurrent short-lived episodic abdominal pain to recurrent severe watery diarrhea, which has a 5-10% mortality rate [1]
Cardiac arrhythmias associated with heart failure refractory to treatment were present in a child infected and completely resolved with anti-helminthic treatment.
Diagnosis is by examination of stools, in search of the eggs of the parasite, but is highly dependent on the skill and technique of the laboratory worker, with previous diagnoses missed by other hospital labs and only noted after examination at The Queen Elizabeth Hospital in Woodville, Adelaide, South Australia.
Treatment with a round of praziquantel results in complete resolution of symptoms and clearance of eggs from stools.
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.
Digenea is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date.
Clonorchiasis is an infectious disease caused by the Chinese liver fluke and two related species. Clonorchiasis is a known risk factor for the development of cholangiocarcinoma, a neoplasm of the biliary system.
Trematodes are parasitic flatworms of the class Trematoda, specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions.
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.
Dicrocoelium dendriticum, the lancet liver fluke, is a parasite fluke that tends to live in cattle or other grazing mammals.
Leucochloridium paradoxum, the green-banded broodsac, is a parasitic flatworm. Its intermediate hosts are land snails, usually of the genus Succinea. The pulsating, green broodsacs fill the eye stalks of the snail, thereby attracting predation by birds, the primary host. These broodsacs visually imitate caterpillars, a prey of birds. The adult parasite lives in the bird's cloaca, releasing its eggs into the faeces.
Metagonimoides oregonensis is a trematode, or fluke worm, in the family Heterophyidae. This North American parasite is found primarily in the intestines of raccoons, American minks, frogs in the genus Rana, and freshwater snails in the genus Goniobasis. It was first described in 1931 by E. W. Price. The parasite has a large distribution, from Oregon to North Carolina. Adult flukes vary in host range and morphology dependent on the geographical location. This results in different life cycles, as well as intermediate hosts, across the United States. On the west coast, the intermediate host is freshwater snails (Goniobasis), while on the east coast the intermediate host is salamanders (Desmognathus). The parasites on the west coast are generally much larger than on the east coast. For example, the pharynx as well as the body of the parasite are distinctly larger in Oregon than in North Carolina. The reverse pattern is observed on the east coast for uterine eggs, which are larger on the west coast. In snails, there is also a higher rate of infection in female snails than in males. Research on the life history traits of the parasites have been performed with hamsters and frogs as model species.
Leucochloridium variae, the brown-banded broodsac, is a species of trematode whose life cycle involves the alternate parasitic infection of certain species of snail and bird. While there is no external evidence of the worm's existence within the bird host, the infection of the snail host is visible when its eye stalks become grotesquely engorged with the parasite's brood sacs. These brood sacks pulsate and move to imitate insect larva, attracting the parasite's next host, insectivore birds. The bird rips off the eye stalk and eats it, thus becoming infected. Later on, the parasite's eggs are dropped with the bird's feces. Similar life-histories are found in other species of the genus Leucochloridium, including Leucochloridium paradoxum.
Brachylaima cribbi is a species of terrestrial trematode parasites in the family Brachylaimidae.
Fasciolopsis is a genus of trematodes. They are also known as giant intestinal flukes.
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.
Halipegus eccentricus is a monoecious, digenea parasitic trematode commonly found in true frogs in North America. It was first described in 1939.
Echinostoma revolutum is a trematode parasite of which the adults can infect birds and mammals, including humans. In humans, it causes echinostomiasis.
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. H. heterophyes is found in the Middle East, West Europe and Africa. 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. Humans and mammals will come in contact with this parasite by the consumption of contaminated or raw fish. This parasite is one of the smallest endoparasite to infect humans. It can cause intestinal infection called heterophyiasis.
Clinostomum marginatum is a species of parasitic fluke. It is commonly called the "yellow grub". It is found in many freshwater fish in North America, and no fish so far is immune to this parasite. It is also found in frogs. Clinostomum marginatum can also be found in the mouth of aquatic birds such as herons and egrets. They are commonly present in the esophagus of fish-eating birds and reptiles. Eggs of these trematodes are shed in the feces of aquatic birds and released into water. Aquatic birds become hosts of this parasite by ingesting infected freshwater fish. The metacercariae are found right beneath the skin or in the muscles of host fish.
Alaria is a genus of flatworms, or trematodes, in the family Diplostomidae.
Metagonimus yokogawai, or the Yokogawa fluke, is a species of a trematode, or fluke worm, in the family Heterophyidae.
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.
| Authority control databases: National |
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