Kidney worm
| Kidney worm | ||||||||||||
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Kidney worm from the abdominal cavity of a dog |
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| Scientific name | ||||||||||||
| Dioctophyme renale | ||||||||||||
| ( Goeze , 1782) |
The kidney worm or giant kidney worm ( Dioctophyme renale , syn .: Dioctophyma renale ) is a parasitic nematode , the adult form of which attacks the kidneys and occasionally the abdominal cavity of mammals .
It is one of the largest known parasitic nematodes in mammals: females can reach lengths of over a meter with a diameter of 10 to 12 mm. The parasite mainly affects predators such as dogs and marten- like animals, and it is rare today for humans to be infected. Kidney worm infestation usually results in the destruction of one or both of the host's kidneys .
history
The kidney worm was first described in 1782 by Johann August Ephraim Goeze , who discovered the worm in a dog's kidney. The species belongs to the family Dioctophymidae and the genus Dioctophyme , where the spelling Dioctophyma was used for a long time . In 1987 the International Commission on Zoological Nomenclature made the generic name Dioctophyme binding.
distribution
The kidney worm is distributed worldwide, but is less common in Africa and Oceania than in the rest of the world. Its main final hosts are fish-eating mammals, including minks and domestic dogs .
The parasite is mainly found in the temperate climate zone . Minks are the most common final hosts, although infestations may be more common locally, particularly in parts of the Canadian province of Ontario and the US state of Minnesota . In these regions, up to 50% of minnows can be carriers of the parasite. Infestation in humans is very rare; the kidney worm is most common in humans around the Caspian Sea , with the highest prevalence in Iran .
In 2003, kidney worm eggs were detected in six human coprolites from the Neolithic pile dwelling settlement Arbon -Bleiche 3 in the canton of Thurgau in Switzerland . The finds were dated to 3384–3370 BC. Dated. This suggests that kidney worm infestation from eating fish was likely to be more common during this period, presumably because inadequate cooking techniques were used.
morphology
The kidney worm has a pronounced sexual dimorphism . Adult males reach a length of 20-40 cm with a diameter of 5-6 mm, whereas adult females can reach a length of up to 103 cm with a diameter of 10-12 mm. Both sexes are bright red and tapering at both ends. Male worms have a bursa at their rear end , by means of which they can attach themselves to the female worms when they mate.
The eggs of the kidney worm are oval, not embryonated at the time of excretion , yellow-brown in color and 60–80 μm in length with a diameter of 39–47 μm. They have a characteristic thick shell. Its surface is rough except for the ends.
Life cycle
Adult kidney worms typically infect the right kidney of the final host where they mate. The females then lay eggs, which are excreted in the urine . These eggs embryon in water after 15 to 100 days. The eggs are ingested by little bristles living in the water (including the earthworm ), which act as intermediate hosts. The worm larvae hatch in the intermediate host and molt to larva 3. The larvae can then accumulate in various foraging hosts that feed on such little bristles, with fish and amphibians playing a role in particular .
If a mammal takes on an infected intermediate or foraging host, the larvae penetrate the intestinal wall and migrate to the liver , where they remain for about 50 days. They then migrate to the kidneys (typically the right kidney), where they enter the renal pelvis and mate there. Kidney worms can survive within the kidney for up to five years and destroy the organ in the process. Occasionally, they can perforate the kidney and migrate into the abdominal cavity .
The main final host of the kidney worm is the mink . In addition, other predators such as wolves , coyotes , foxes , dogs , weasels , raccoons and bears can also act as final hosts. The kidney worm can also affect humans, although the infection usually results from eating insufficiently cooked freshwater fish or frogs .
In practice, the mink plays a major role as a reservoir for the pathogen, but any possible final host can excrete the eggs with the urine and thus become a source of infection.
clinic
An infestation with the kidney worm leads to less specific symptoms, typically including hematuria and pain in the lumbar region; additionally, it may by the penetration of the worm in the ureter to renal colic come. In most cases only one kidney is affected, which is destroyed by fibrotic changes. Bilateral infestation can lead to death from kidney failure .
In the blood can often eosinophilia detected. If worms of both sexes are in the same kidney, eggs are excreted in the urine, the detection of which is diagnostic. The diagnosis is often made by chance during an ultrasound examination or a computed tomography .
There is no standardized treatment for kidney worm infestation in humans. The worms are usually removed surgically , and depending on their condition, the affected kidney is also removed ( nephrectomy ). This treatment is also common in veterinary medicine . In addition, there is a case description of a successful drug treatment with ivermectin in a person with kidney worm infestation.
Web links
- Photo of a surgically removed female kidney worm
- Surgical Removal of Kidney Worms from a Dog - University of Guelph Video Documentation
Individual evidence
- ↑ a b c Animal Parasitology February 5, 2001. Kansas State University , accessed May 25, 2014.
- ↑ a b c d Palmer and Reeder: Kidney Worm: Dioctophymiasis and Eustrongylidiasis. Tropical Medicine Central Resource. International Society of Radiology. 22 Feb 2009.
- ↑ a b L. DAVID MECH, SHAWN P. TRACY: Prevalence of Giant Kidney Worm (Dioctophyma renale) in Wild Mink (Mustela vison) in Minnesota. In: The American Midland Naturalist. 145, 2001, p. 206, doi : 10.1674 / 0003-0031 (2001) 145 [0206: POGKWD] 2.0.CO; 2 .
- ^ A b I. Ignjatovic, I. Stojkovic, C. Kutlesic, S. Tasic: Infestation of the Human Kidney with Dioctophyma renale . In: In: Urol Int. 2003; 70, pp. 70-73 doi: 10.1159 / 000067695
- ↑ M. Le Bailly, U. Leuzinger, F. Bouchet: Dioctophymidae Eggs in Coprolites From Neolithic Site of Arbon – Bleiche 3 (Switzerland). In: Journal of Parasitology. 89, 2003, p. 1073, doi : 10.1645 / GE-3202RN .
- ^ Urinary System Diseases, Animals. Parasitology Research & Encyclopedic Reference of Parasitology. University of Würzburg , February 22, 2009.
- ↑ a b Dioctophyme renal infection in bears (Parasitic Disease Summary) . February 22, 2009.
- ↑ Lena N. Measures, Roy C. Anderson: Centrachid Fish as Paratenic Hosts of the Giant Kidney Worm, Dioctophyma Renale (Goeze, 1782), in Ontario, Canada In: Journal of Wildlife Diseases. 21, 1985, pp. 11-19, doi : 10.7589 / 0090-3558-21.1.11 .
- ↑ TF MACE: Lesions in Mink (Mustela vision) Infected with Giant Kidney Worm (Dioctophyma renale). In: Journal of Wildlife Diseases. 12, 1976, p. 88, doi : 10.7589 / 0090-3558-12.1.88 .
- ↑ Carlos Torres Ribeiro, Guilherme Gomes Verocai, Luiz Eduardo Roland Tavares: Dioctophyme renale (Nematoda, Dioctophymatidae) Infection in the Crab-eating Fox (Cerdocyon thous) from Brazil. In: Journal of Wildlife Diseases. 45, 2009, p. 248, doi : 10.7589 / 0090-3558-45.1.248 .
- ↑ TL Nakagawa, AP Bracarense, AC dos Reis, MH Yamamura, SA Headley: Giant kidney worm (Dioctophyma renale) infections in dogs from Northern Paraná, Brazil. In: Veterinary parasitology. Volume 145, number 3-4, April 2007, pp. 366-370, doi : 10.1016 / j.vetpar.2006.10.027 , PMID 17156927 .
- ^ NS Charisis, KM Vassalos: An Introduction to FOODBORNE DISEASES & HACCP Systems ( Memento from September 27, 2006 in the Internet Archive ). In: Rep. Mediterranean Zoonoses Control Center / World Health Organization.
- ^ Parasitology International. 2013 Oct; 62 (5), pp. 459-460 doi: 10.1016 / j.parint.2013.06.007 .