Pulmonary Hydatid Disease
Zoonosis caused by larval stage of the parasite Echinococcus (Cestoda class,
Echinococcus genus, family Taeniidae, Order Cyclophylilidea, Subphylum Plathelmintes)
There are 4 different main types from the epidemiological, morphological and biological
point of view, caused by:
1) E. granulosus
most often found in large pastures of the world: Mediterranean, Africa, South America,
Middle East, Australia and New Zealand.
The most common cause of hydatid disease in humans
PASTORAL (domestic) FORM:
Final host: dog
Intermediate host: sheep, cow, camel
Sylvan (wild) FORM:
Final host: wolf
Intermediate host: deer, caribou
2) E. multilocularis:
Alveolar form of hydatid disease
Final host: wolves, foxes, coyotes, dog, cat
Intermediate host: mice
In human 98% invade liver and has cancer-like developement!
3) E. vogel i
Tropical America (Panama, Ecuador, Colombia, Venezuela and French Guyana)
Final host: wild dogs
Host intemediar : paca ă
1
, Rarely affects man Results in polycystic disease, affecting 100% liver and other
viscera, ... eg lung, through
direct spread!
4) E. oligarthus
Brazil, Venezuela, Suriname, India
Final host: wild cats
Intermediate host: rat
Affects man very rarely
Results in extrahepatic polycystic disease (mandible, orbit, heart, etc.).
Life cycle of E. granulosus:
Adult parasite lives in the proximal small intestine of definitive host, attached by hooks
to mucosa - time, 5-20 months.
Eggs are released into the host's intestine and are excreted in faeces.
Sheep are the most common intermediate hosts (eating the eggs while grazing on
contaminated land).
The egg loses its protective layer of during digestion in the duodenum.
The embryo is delivered, or oncosfera, passing through the intestinal wall in portal
circulation and develops into a cyst in the.
When the definitive host eats the viscera of intermediate host, the cycle is complete.
2
Zoonosis caused by larval stage of the parasite Echinococcus (Cestoda class,
Echinococcus genus, family Taeniidae, Order Cyclophylilidea, Subphylum Plathelmintes)
There are 4 different main types from the epidemiological, morphological and biological
point of view, caused by:
1) E. granulosus
most often found in large pastures of the world: Mediterranean, Africa, South America,
Middle East, Australia and New Zealand.
The most common cause of hydatid disease in humans
PASTORAL (domestic) FORM:
Final host: dog
Intermediate host: sheep, cow, camel
Sylvan (wild) FORM:
Final host: wolf
Intermediate host: deer, caribou
2) E. multilocularis:
Alveolar form of hydatid disease
Final host: wolves, foxes, coyotes, dog, cat
Intermediate host: mice
In human 98% invade liver and has cancer-like developement!
3) E. vogel i
Tropical America (Panama, Ecuador, Colombia, Venezuela and French Guyana)
Final host: wild dogs
Host intemediar : paca ă
1
, Rarely affects man Results in polycystic disease, affecting 100% liver and other
viscera, ... eg lung, through
direct spread!
4) E. oligarthus
Brazil, Venezuela, Suriname, India
Final host: wild cats
Intermediate host: rat
Affects man very rarely
Results in extrahepatic polycystic disease (mandible, orbit, heart, etc.).
Life cycle of E. granulosus:
Adult parasite lives in the proximal small intestine of definitive host, attached by hooks
to mucosa - time, 5-20 months.
Eggs are released into the host's intestine and are excreted in faeces.
Sheep are the most common intermediate hosts (eating the eggs while grazing on
contaminated land).
The egg loses its protective layer of during digestion in the duodenum.
The embryo is delivered, or oncosfera, passing through the intestinal wall in portal
circulation and develops into a cyst in the.
When the definitive host eats the viscera of intermediate host, the cycle is complete.
2
