Cercaria

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A cercaria (plural cercariae) is a larval form of the trematode class of parasites. It develops within the germinal cells of the sporocyst or redia. [1] A cercaria has a tapering head with large penetration glands. [2] It may or may not have a long swimming "tail", depending on the species. [1] The motile cercaria finds and settles in a host where it will become either an adult, or a mesocercaria, or a metacercaria, according to species.

Cercarial infection in water environments by non-human schistosome species causes dermatologic burden to nearby swimmers, fishermen and farmers. The cycle as mentioned above, starts with egg distribution whether fecal in route or from the nostril of a duck or goose. [3] : 157–159  Miracidia infect snail reservoirs and form successive sporocysts. Released cercariae travel and infect nearby non-human mammals or birds, depending on species, or accidental hosts such as humans. This dead-end infection and host allergic reaction has been referred to as cercarial dermatitis or "swimmer's itch". [4] [5] Dermatitis can also be seen following exposure to the cercariae of schistosome species that cause patent infections in humans (schistosomiasis) in endemic areas. [6]

Among fish, infection beneath the scale bedding by cercariae of other trematode species can result in black spot disease. [7] [8] This is an example of an encysted form, or metacercaria. For some trematode species, cercarial encystment takes place on aquatic plants (e.g. in the liver fluke Fasciola gigantica [9] and the intestinal fluke Fasciolopsis buski [10] ).

The term Cercaria is also used as a genus name in descriptions of species when only the larval form is known. [11]

Rotifers ( Rotaria rotatoria) produce a chemical, Schistosome Paralysis Factor, that suppresses cercaria swimming and reduces infections. [12]

Related Research Articles

<span class="mw-page-title-main">Schistosomiasis</span> Human disease caused by parasitic worms called schistosomes

Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody stool, or blood in the urine. Those who have been infected for a long time may experience liver damage, kidney failure, infertility, or bladder cancer. In children, schistosomiasis may cause poor growth and learning difficulties.

<span class="mw-page-title-main">Trematoda</span> Class of parasitic flatworms

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.

<span class="mw-page-title-main">Digenea</span> Class of flukes

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.

<span class="mw-page-title-main">Fasciolopsiasis</span> Medical condition

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.

<i>Fasciola</i> Genus of flukes

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.

<i>Fasciola gigantica</i> Species of fluke

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.

<span class="mw-page-title-main">Trematode life cycle stages</span>

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.

<i>Trichobilharzia regenti</i> Species of fluke

Trichobilharzia regenti is a neuropathogenic parasitic flatworm of birds which also causes cercarial dermatitis in humans. The species was originally described in 1998 in the Czech Republic and afterwards it was detected also in other European countries, e.g. Denmark, Germany, France, Iceland, Poland, Switzerland, or Russia, and even in Iran. For its unique neurotropic behaviour in vertebrate hosts, the host-parasite interactions are extensively studied in terms of molecular biology, biochemistry and immunology.

<i>Schistosoma mansoni</i> Species of fluke

Schistosoma mansoni is a water-borne parasite of humans, and belongs to the group of blood flukes (Schistosoma). The adult lives in the blood vessels near the human intestine. It causes intestinal schistosomiasis. Clinical symptoms are caused by the eggs. As the leading cause of schistosomiasis in the world, it is the most prevalent parasite in humans. It is classified as a neglected tropical disease. As of 2021, the World Health Organization reports that 251.4 million people have schistosomiasis and most of it is due to S. mansoni. It is found in Africa, the Middle East, the Caribbean, Brazil, Venezuela and Suriname.

<span class="mw-page-title-main">Swimmer's itch</span> Itchy skin lesions due to infection by water-borne parasitic flatworms

Swimmer's itch, cercarial dermatitis or schistosome dermatitis is a short-term allergic contact dermatitis occurring in the skin of humans that have been infected by water-borne schistosomes, a type of flatworm. It is common in freshwater, brackish and marine habitats worldwide. The incidence of this condition may be increasing, although this may be attributed to better monitoring and reporting. Nevertheless, the condition is considered to be an emerging infectious disease.

<i>Schistosoma intercalatum</i> Species of fluke

Schistosoma intercalatum is a parasitic worm found in parts of western and central Africa. There are two strains: the Lower Guinea strain and the Zaire strain. S. intercalatum is one of the major agents of the rectal form of schistosomiasis, also called bilharzia. It is a trematode, and being part of the genus Schistosoma, it is commonly referred to as a blood-fluke since the adult resides in blood vessels.

<i>Schistosoma haematobium</i> Species of fluke

Schistosoma haematobium is a species of digenetic trematode, belonging to a group (genus) of blood flukes (Schistosoma). It is found in Africa and the Middle East. It is the major agent of schistosomiasis, the most prevalent parasitic infection in humans. It is the only blood fluke that infects the urinary tract, causing urinary schistosomiasis, and is a leading cause of bladder cancer. The diseases are caused by the eggs.

<span class="mw-page-title-main">Fasciolidae</span> Family of flukes

Fasciolidae is a family of trematodes and includes several parasites involved in the veterinary and medical sciences, which cause the disease Fasciolosis. Fasciolidae is divided into five genera by Olson et al. 2003. The family's various species are localised in liver, gall bladder, and intestine. Their life-cycle includes an intermediate host, freshwater snails from the family Lymnaeidae.

<i>Fasciolopsis</i> Genus of flukes

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

Schistosoma mekongi is a species of trematodes, also known as flukes. It is one of the five major schistosomes that account for all human infections, the other four being S. haematobium, S. mansoni, S. japonicum, and S. intercalatum. This trematode causes schistosomiasis in humans.

<span class="mw-page-title-main">Bivitellobilharzia nairi</span> Species of fluke

Bivitellobilharzia nairi is a species of trematodes, part of the family Schistosomatidae. This is a fairly new identified endoparasite that was found in 1945 by Mudaliar and Ramanujachari, who first recorded the parasite in India. Researchers collected fecal samples of the Indian rhinoceros and were startled to find B. nairi eggs.

<span class="mw-page-title-main">Trematodiasis</span> Medical condition

Trematodiasis is a group of parasitic infections caused by different species of flukes, in humans mainly by digenean 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.

<i>Trichobilharzia</i> Genus of flukes

Trichobilharzia is a genus of trematodes in the family Schistosomatidae. They are worldwide distributed parasites of anatid birds and causative agents of human cercarial dermatitis.

Heterobilharzia is a genus of trematodes in the family Schistosomatidae. The species Heterobilharzia Americana is a parasite of the Southeastern United States and typically found in raccoons. Species of this genus are responsible for Schistosoma in canines. Cercariae found in freshwater may also cause Swimmer's itch in humans.

<span class="mw-page-title-main">Gastropod-borne parasitic disease</span> Medical condition

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

  1. 1 2 "Glossary". VPTH 603 Veterinary Parasitology. University of Pennsylvania School of Veterinary Medicine. Archived from the original on 2011-07-18. Retrieved 2019-05-22.
  2. ↑ "Schistosoma". Australian Society for Parasitology. Retrieved 19 February 2011.
  3. ↑ Horák, P.; Kolářová, L.; Adema, C.M. (2002). "Biology of the Schistosome Genus Trichobilharzia". Advances in Parasitology. 52: 155–233. doi:10.1016/S0065-308X(02)52012-1. ISSN   0065-308X.
  4. ↑ National Center for Emerging and Zoonotic Infectious Diseases, Division of Parasitic Diseases and Malaria (10 May 2019). "Cercarial Dermatitis". DPDx. U.S. Centers for Disease Control and Prevention. Retrieved 21 December 2024.
  5. ↑ "About Swimmer's Itch". Swimmer's Itch (Cercarial Dermatitis). U.S. Centers for Disease Control and Prevention. 10 September 2024. Retrieved 21 December 2024.
  6. ↑ Kolářová, L.; Horák, P.; Skírnisson, K.; Marečková, H.; Doenhoff, M. (2012). "Cercarial Dermatitis, a Neglected Allergic Disease". Clinical Reviews in Allergy & Immunology. 45 (1): 63–74. doi:10.1007/s12016-012-8334-y.
  7. ↑ Pyzer, Gord (8 January 2018). "The Real Truth About Black Spot Disease, and How It Affects Fish". Outdoor Canada. Retrieved 21 December 2024.
  8. ↑ Meyers, Theodore; Burton, Tamara; Bentz, Collette; Ferguson, Jayde; Stewart, Davis; Starkey, Norman (July 2019) [Originally published in 2007]. "Black Spot Disease (Neascus and Heterphyids)" (PDF). DISEASES OF WILD AND CULTURED FISHES IN ALASKA. Fish Pathology Laboratories, Alaska Department of Fish and Game. pp. 78–79. OCLC   1104329201 . Retrieved 21 December 2024.
  9. ↑ Carmona, Marcus (2013). Mulcrone, Renee (ed.). "Fasciola gigantica". Animal Diversity Web. Retrieved 21 December 2024.
  10. ↑ Greiner, Lindsey (2011). Liere, Heidi; Marino, John; OConnor, Barry; Mulcrone, Renee (eds.). "Fasciolopsis buski". Animal Diversity Web. Retrieved 21 December 2024.
  11. ↑ "Cercaria Müller, 1773". WoRMS. World Register of Marine Species. 2023. Retrieved 2023-02-26.
  12. ↑ Gao, Jiarong; Yang, Ning; Lewis, Fred A.; Yau, Peter; Collins, James J.; Sweedler, Jonathan V.; Newmark, Phillip A. (2019). Khosla, Chaitan (ed.). "A rotifer-derived paralytic compound prevents transmission of schistosomiasis to a mammalian host". PLOS Biology. 17 (10): e3000485. doi: 10.1371/journal.pbio.3000485 . ISSN   1545-7885. PMC   6797223 . PMID   31622335.
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