Echinococcosis 61593 225394143 2008-07-13T13:16:49Z RDBrown 539176 /* References */ => Cite journal,book using Wikipedia template filling {{DiseaseDisorder infobox | Name = Echinococcosis | Image = Echinococcus Life Cycle.png | Caption = Echinococcus life cycle (click to enlarge) | ICD10 = {{ICD10|B|67||b|65}} | ICD9 = {{ICD9|122.4}}, {{ICD9|122}} | ICDO = | OMIM = | DiseasesDB = 4048 | MedlinePlus = | eMedicineSubj = med | eMedicineTopic = 629 | eMedicine_mult = {{eMedicine2|med|1046}} | MeshID = | }} '''Echinococcosis''', also known as '''hydatid disease''', '''hydatid cyst''', '''unilocular hydatid disease''' or '''cystic echinococcosis''', is a potentially fatal [[parasitic disease]] that can affect many [[animal]]s, including [[wildlife]], commercial [[livestock]] and [[human]]s. The disease results from infection by [[tapeworm]] [[larva]]e of the [[genus]] ''[[Echinococcus]]'' - notably ''[[Echinococcus granulosus|E. granulosus]]'', ''[[Echinococcus multilocularis|E. multilocularis]]'', and ''[[Echinococcus vogeli|E. vogeli]]''. ==Infection cycle== Like many other parasite infections, the course of Echinococcus infection is complex. The worm has a life cycle that requires ''[[intermediate host|definitive hosts]]'' and ''[[intermediate host|intermediate hosts]]''. Definitive hosts are normally [[carnivores]] such as [[dog]]s, while intermediate hosts are usually [[herbivores]] such as [[sheep]] and [[cattle]]. Humans also function as intermediate hosts, although they are usually a 'dead end' for the parasitic infection cycle. [[Image:Hydatid_sand_DPDx.JPG|thumb|Echinococcus organisms taken from a hydatid cyst]] [[Image:hydatid_cyst_membrane.jpg|thumb|appearance of a typical cyst at removal]] The disease cycle begins with an adult tapeworm infecting the [[intestine|intestinal tract]] of the definitive host. The adult tapeworm then produces eggs which are expelled in the host's [[feces]]. Intermediate hosts become infected by ingesting the [[egg (biology)|eggs]] of the parasite. Inside the intermediate host, the eggs hatch and release tiny hooked [[embryo]]s which travel in the bloodstream, eventually lodging in an organ such as the [[liver]], [[lung]]s and/or [[kidneys]]. There, they develop into hydatid [[cyst]]s. Inside these cysts grow thousands of tapeworm larvae, the next stage in the life cycle of the parasite. When the intermediate host is [[predator|predated]] or [[scavenger|scavenged]] by the definitive host, the larvae are eaten and develop into [[adult]] tapeworms, and the infection cycle restarts. ==Disease symptoms== As already noted, ''Echinococcus'' infection causes large cysts to develop in intermediate hosts. Disease symptoms arise as the cysts grow bigger and start eroding and/or putting pressure on blood vessels and organs. Large cysts can also cause [[shock (medical)|shock]] if they happen to rupture. Infection with ''E. granulosus'', common in [[Mediterranean Sea|Mediterranean]] countries, typically results in the formation of hydatid [[cyst]]s in the liver, lungs, kidney and [[spleen]] of the intermediate host. In [[echography]] or [[CT scan]]s, hydatid cysts are often large with a flaky appearance (this is referred to as "hydatid sand"); this indicates the first stage of infection. In the second stage, medical imaging may show multiple daughter cysts. Hydatid cyst of liver can be accurately diagnosed by a [[serology|serologic]] assay ([[Weinberg reaction]]). However, the Weinberg reaction is falsely negative in as many as 50% of people with cysts.{{Fact|date=April 2007}} [[Eosinophilia]] is not a feature of cysts unless rupture occurs. In fact, usually there are no changes in blood biochemistry. Hydatid disease of lung or liver is generally asymptomatic but can cause serious complications if rupture of cyst occur. Systemic anaphylaxis is usually associated with cyst rupture and can be predicted by positivity of Casoni reaction. There is also risk of intrapleural or intraperitoneal dissemination of the disease and of secondary infection that causes a lung or hepatic [[abscess]]. This condition is also known as ''cystic hydatid disease'' and can sometimes be successfully treated with [[surgery]] to remove the cysts. In [[Portugal]] there is also some experience with PAIR (Percutaneous Aspiration, Infusion of scolicidal agents and Reaspiration of cyst content) and medical therapy with [[albendazole]] alone in the dose of 400 mg twice daily. Therapy with albendazole or [[praziquantel]] should be initiated before any procedure and prolonged 28 days if dissemination of hydatid cyst is to be avoided. Infection with ''E. multilocularis'' results in the formation of dense parasitic [[tumor]]s in the liver, lungs, brain and other organs.Sometimes the infection in brain may cause tumour like symptoms and it needs removal by surgical means.[http://www.youtube.com/watch?v=AfNWBo1toY0]. This condition, also called ''alveolar hydatid disease'' is more likely to be fatal. Infection with Echinococcus vogeli, restricted to [[Central America|Central]] and [[South America]] is characterized by polycystic disease. Unlike intermediate hosts, definitive hosts are usually not hurt very much by the infection. Sometimes, a lack of certain vitamins and minerals can be caused in the host by the very high demand of the parasite. ==Prophylaxis== There are several strategies to prevent echinococcosis, most of which involve disruption of the parasite's life cycle. For instance, feeding raw [[offal]] to work dogs is a key point of infection in a [[farm]] environment and is strongly discouraged. Also, basic hygiene practices such as thoroughly cooking food and vigorous hand washing before meals can prevent the eggs entering the human digestive tract. Regular "worming" of farm dogs with the drug praziquantel also helps kill the tapeworm. By employing such simple practices, hydatids have been virtually eliminated in [[New Zealand]], where it was once very common. Effective [[vaccine]]s, based on [[recombinant DNA]] technology, are being developed in [[Australia]] for sheep. ==Investigations== * Blood CP * Serology * Casoni's Reaction * X-Ray Abdomen * USG and CT Scanning * ERCP (Endoscopic retrograde Cholangio-Pancreatography) ==Treatment== * [[Metronidazole]] 400-600mg * [[Albendazole]] * [[Surgical]] * [[Marsupialization]] * [[Omentopexy]] * Laminated Membrane Removal * [[Mebendazole]] to prevent recurrence Praziquan, tab 20 mg/kg 12 hourly for 2 weeks is given pre operativly ==References== # {{cite book |author=Alimuddin I. Zumla; Gordon C. Cook; Manson, Patrick |title=Manson's tropical diseases |publisher=Saunders |location=Philadelphia |year=2003 |chapter=Section 10: Helminthic Infections 83. Echinococcosis/Hydatidosis |pages= |isbn=0-7020-2640-9 |oclc= |doi= |accessdate=}} #{{cite journal |author=Sailer M, Soelder B, Allerberger F, Zaknun D, Feichtinger H, Gottstein B |title=Alveolar echinococcosis of the liver in a six-year-old girl with acquired immunodeficiency syndrome |journal=J. Pediatr. |volume=130 |issue=2 |pages=320–3 |year=1997 |month=February |pmid=9042141 |doi= |url=http://linkinghub.elsevier.com/retrieve/pii/S0022-3476(97)70364-0}} #{{cite journal |author=Reuter S, Schirrmeister H, Kratzer W, Dreweck C, Reske SN, Kern P |title=Pericystic metabolic activity in alveolar echinococcosis: assessment and follow-up by positron emission tomography |journal=Clin. Infect. Dis. |volume=29 |issue=5 |pages=1157–63 |year=1999 |month=November |pmid=10524957 |doi= |url=http://www.journals.uchicago.edu/cgi-bin/resolve?CID990045}} {{Unreferenced|date=April 2007}} {{Helminthiases}} [[Category:Dog diseases]] [[Category:Parasitic diseases]] [[bg:Кучешка тения]] [[de:Zystische_Echinokokkose]] [[es: Hidatidosis]] [[is:Höfuðsótt]] [[it:Echinococcosi]] [[nl:Echinokokkose]] [[pt:Equinococose]] [[sv:Echinokockinfektion]]