Difference between revisions of "Echinococcus multilocularis"

Latest revision as of 15:00, 6 July 2012

Echinococcus multilocularis
Kingdom	Animalia
Phylum	Platyhelminthes
Class	Cestoda
Sub-class	Eucestoda
Order	Cyclophyllidea
Family	Taeniidae
Genus	Echinococcus
Species	E. multilocularis

Also known as: Dwarf fox tapeworm

Overview

Rat infected with E. multilocularis - Dr. I. Kagan

E. multilocularis is not present in the UK but is endemic in central Europe and North America. It is zoonotic and so presents a major health problem in Europe (including Switzerland where urban foxes are now infected) having spread from 4 countries in the 1980s to being found in 12 countries now. This has been attributed to the anti-rabies campaign which has increased the number of foxes which are commonly found as the definitive host. Humans can act as intermediate hosts if eggs are ingested causing the formation of hydatid cysts in the liver, these rapidly invade the liver and are inoperable.

Characteristics

E. mulitlocularis is a relatively small tapeworm between 2-4mm as an adult.
Scolex

2 rows of hooks
4 suckers

Proglottid

Between 3 - 5 segments in total
Terminal proglottid forms 1/2 the length of the mature worm
1 proglottid shed per week
Has single genital pore

Eggs

200-300 eggs per mature proglottid
30-40μm in diameter
Striated shell
Hooks visible on oncosphere

Life Cylce

E. multilocularis has a typical cestode life cycle involving the formation of a metacestode cyst in the intermediate host before developing to adulthood in the definitive host. The definitive host for E. multilocularis is most commonly the dog, though it has also been seen in the cat. Epidemiologically the most important definitive host in the spread of the disease is the fox. E. multilocularis mainly uses small rodents such as voles, mice and rats as an intermediate host, forming multilobular hydatid cysts in the liver of the host. The short life span of the intermediate host species is the reason for the rapid growth of the cyst, even in longer lived host like humans. This is the stage that generally causes pathology in the host animal and can be fatal.

Epidemiology

E. mulitilocularis is found throughout the northern hemisphere, originally its primary range was the tundra of northern Russia and eastern Europe. The prevalence of this worm is increasing to encompass many urban areas which increases the risk of zoonotic infection. The parasites definitive host in the wild is the red fox and the arctic fox. In North America and Europe there is an increasing presence of red foxes in urban and suburban areas, this increases the risk of infection of both humans and pets. The disease it causes is called Alveolar Hydatid Disaese.

Treatment and Control

Control involves treatment of definitive hosts, dogs and cats, with anthelmintics in order to remove adult worms from the host. The treatment of intermediate host pets (and humans) is not routine and can be dangerous as due to the infiltrative nature of the hydatid cyst and its metastatic ability. Surgical removal of the cyst is therefore not advisable.

Echinococcus multilocularis Learning Resources
Flashcards Test your knowledge using flashcard type questions	Cestode Flashcards
Literature Search Search for recent publications via CAB Abstract (CABI log in required)	Echinococcus multilocularis publications since 2000

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@@ Line 1: / Line 1: @@
-{{unfinished}}
+{{OpenPagesTop}}
+{{Taxobox
+|kingdom            =Animalia
+|phylum             =Platyhelminthes
+|class              =[[:Category:Cestodes|Cestoda]]
+|sub-class          =Eucestoda
+|order              =[[:Category:Cyclophyllidea|Cyclophyllidea]]
+|super-family       =
+|family             =[[:Category:Taeniidae|Taeniidae]]
+|sub-family         =
+|genus              =Echinococcus
+|species            =''E. multilocularis''
+}}
+Also known as: '''''Dwarf fox tapeworm
+==Overview==
+[[Image:Rat infected with E. multilocularis.jpg|thumb|right|150px|Rat infected with ''E.  multilocularis'' - Dr. I. Kagan]]
+''E. multilocularis'' is not present in the UK but is endemic in central Europe and North America. It is zoonotic and so presents a major health problem in Europe (including Switzerland where urban foxes are now infected) having spread from 4 countries in the 1980s to being found in 12 countries now. This has been attributed to the anti-rabies campaign which has increased the number of foxes which are commonly found as the definitive host. Humans can act as intermediate hosts if eggs are ingested causing the formation of hydatid cysts in the liver, these rapidly invade the liver and are inoperable.
+==Characteristics==
+''E. mulitlocularis'' is a relatively small tapeworm between 2-4mm as an adult.<br>
+'''Scolex'''
+*2 rows of hooks
+*4 suckers
+'''Proglottid'''
+*Between 3 - 5 segments in total
+*Terminal proglottid forms 1/2 the length of the mature worm
+*1 proglottid shed per week
+*Has single genital pore
+'''Eggs'''
+*200-300 eggs per mature proglottid
+*30-40μm in diameter
+*Striated shell
+*Hooks visible on oncosphere
+==Life Cylce==
+''E. multilocularis'' has a typical [[Cyclophyllidea Life-Cycle|cestode life cycle]] involving the formation of a metacestode cyst in the intermediate host before developing to adulthood in the definitive host. The definitive host for ''E. multilocularis'' is most commonly the dog, though it has also been seen in the cat. Epidemiologically the most important definitive host in the spread of the disease is the fox. ''E. multilocularis'' mainly uses small rodents such as voles, mice and rats as an intermediate host, forming multilobular hydatid cysts in the liver of the host. The short life span of the intermediate host species is the reason for the rapid growth of the cyst, even in longer lived host like humans. This is the stage that generally causes pathology in the host animal and can be fatal.
+==Epidemiology==
+''E. mulitilocularis'' is found throughout the northern hemisphere, originally its primary range was the tundra of northern Russia and eastern Europe. The prevalence of this worm is increasing to encompass many urban areas which increases the risk of zoonotic infection. The parasites definitive host in the wild is the red fox and the arctic fox. In North America and Europe there is an increasing presence of red foxes in urban and suburban areas, this increases the risk of infection of both humans and pets. The disease it causes is called Alveolar Hydatid Disaese.
+==Treatment and Control==
+Control involves treatment of definitive hosts, dogs and cats, with anthelmintics in order to remove adult worms from the host. The treatment of intermediate host pets (and humans) is not routine and can be dangerous as due to the infiltrative nature of the hydatid cyst and its metastatic ability. Surgical removal of the cyst is therefore not advisable.
+{{Learning
+|flashcards = [[Cestodes_Flascards|Cestode Flashcards]]
+|literature search =[http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%22Echinococcus+multilocularis%22&occuring1=title&rowId=2&options2=AND&q2=&occuring2=freetext&rowId=3&options3=AND&q3=&occuring3=freetext&publishedstart=2000&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all&x=43&y=8 ''Echinococcus multilocularis'' publications since 2000]
+}}
-== Alveolar Hydatid Disease (''E. multilocularis'') ==
-[[Image:Rat infected with E. multilocularis.jpg|thumb|right|150px|Rat infected with ''E.  multilocularis'' - Dr. I. Kagan]]
-This parasite does not occur in the UK. It is largely restricted to forest areas of central Europe (including Switzerland where urban foxes are also infected) and North America. It is a significant public health problem and is spreading across Europe, where 12 countries are now affected compared with four in the 1980’s. The metacestode is the alveolar (or multilocular) cyst. Human infections are particularly dangerous as daughter cysts bud off externally as well as internally from the germinal layer so that the cyst rapidly infiltrates the liver like an invasive tumour, and is inoperable. Dogs, and to a lesser extent cats, can become infected with the adult tapeworm, but the main epidemiological cycle involves the fox as the final host and microtine rodents (particularly voles) as intermediate hosts. The latter have a very short life-span – hence the rapid growth-rate of the alveolar cyst in intermediate hosts, including humans. The anti-rabies campaign in Europe has led to a large increase in the number of foxes and, consequently, of infected rodents.
+{{review}}
+{{OpenPages}}
-''Echinococcus granulosus'' in [[Peritoneal Cavity - Parasitic Pathology|Peritoneal Cavity Parasitic]] and [[Muscles Inflammatory - Pathology#Cestodes|muscles]]
-*''Echinococcus granulosus'' in hydatid disease of [[Respiratory Parasitic Infections - Pathology#Hydatid cysts|lungs]]
 [[Category:Taeniidae]]
-[[Category:To_Do_-_NickJ]]
+[[Category:Zoonoses]]
+[[Category:Expert_Review]]