1 / 17

Dicrocoelium dendriticum

Dicrocoelium dendriticum. By Carolynn Peter & Ryan Hamm. Classification. Kingdom Animalia Phylum Platyhelminthes Class Trematoda Order Plagiorchiida Family Dicrocoeliidae Genus Dicrocoelium Species dendriticum. Background.

anja
Download Presentation

Dicrocoelium dendriticum

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dicrocoeliumdendriticum By Carolynn Peter & Ryan Hamm

  2. Classification Kingdom Animalia PhylumPlatyhelminthes Class Trematoda Order Plagiorchiida Family Dicrocoeliidae Genus Dicrocoelium Species dendriticum

  3. Background • Family Dicrocoeliidaeuse land snails as first intermediate host • Known as the “lancet fluke” or “small liver fluke” • Causes the diseasedicrocoellosis • Favors dry conditions • Human infection is rare, but can occur

  4. Morphology • 6 to 10 mm long by 1.5 to 2.5 mm wide • Widest near the middle • Body is pointed at both ends • Lobate testes lie directly behind acetabulum • Loops of the uterus fill most of the body behind ovary

  5. Hosts • Definitive Host: • Ruminants are the usual definitive hosts • Sheep, cattle, goats, deer • Accidental Host: • other herbivorous animals, carnivores, and humans can serve as a host • Intermediate Host: • Land snail (Cionellalubrica) • An ant (Formica fusca)

  6. Geographic Range • Found in: • Most of Europe and Asia • North America • Australia • Northern Africa

  7. Life Stages • Miracidium- first larval stage of a digenetic trematode • Mother sporocyst- asexual stage of development that forms more sporocysts • Cercariae- Juvenile digenetic trematode, produced by asexual reproduction within a sporocyst • Metacercariae- stage between cercaria and adult in the life cycle of most digenetic trematodes D. dendriticum egg containing a miracidium.

  8. Life Cycle • http://www.youtube.com/watch?v=lGSUU3E9ZoM

  9. Life Cycle in the Land Snail (1st intermediate host) • Adult flukes live in the bile ducts within the liver. • Eggs leave the liver and are passed with the feces. • The eggs contain a miracidia. • A land snail must eat the egg before it will hatch. • In the small intestine of the snail, the egg hatches and releases miracidia • The miracidia penetrates the gut wall and develops into a mother sporocyst in the digestive gland. • Mother sporocysts produce daughter sporocysts which produce cercariae . • Three months after infection the cercariae accumulate in the “lung” (mantle cavity) of the snail or on its body surface which causes the snail to produce thick mucus. • The mucous surrounds the cercariae and expels the cercariae in the slime ball as it crawls along.

  10. Life Cycle in the Ant (2nd intermediate host) • Fluke development continues when the cercariae are eaten by the second definitive host an ant. • An ant will eat the slime ball and the cercariae become metacercariae • Most of the metacercariae (infective to definitive host) will encyst in the spaces between the organs of the ant where the blood circulates (hemocoel). • Some metacercariae migrate to the subesophageal ganglion of the ant and encyst there • These metacercariae (not infective to definitive host) are called “Brainworms” and will change the behavior of the ant. • In the evening the ants will crawl to the tops of grasses and other plants and hang from it's mandibles. • When the temperature warms up the ant returns to normal behavior. • On the grass and other plants the ant is susceptible to the definitive host during grazing.

  11. Life Cycle in Definitive Host • Once eaten by a definitive host the metacercariaeexcysts in the duodenum. • It will migrate upstream to the bile ducts since it is attracted to bile and into the liver, mature and produce eggs. • Flukes mature in 6 to 7 weeks • Flukes reproduce by hermaphroditism • Eggs are produced and released in feces of definitive host

  12. Symptoms • No trauma to the gut wall or liver parenchyma resulting from migrating juveniles • Biliary dysfunction • Bile duct inflammation • Fibrosis • Hepatocyte damage • Anemia • Edema • Emaciation

  13. Diagnosis • Traditionally eggs of D. dendriticum are found in feces of infected animals • Post-mortem examination of liver • ELISA using D. dendriticum antigen can catch the disease early on

  14. Treatment • Praziquantel • Benzimidazoles • Albenzole • Fenbenazole • Mebendazole

  15. Control • Animal husbandry practices • Do not allow ruminants to graze in the early morning or at night • Try and control the intermediate hosts • Use chickens, geese or ducks

  16. Quiz Time • What are the two intermediate hosts? • Land Snail and an Ant • What is the geographic range of D. dendriticum? • Most of Europe and Asia, North America, Australia, Northern Africa • Who are the accidental host? • Other herbivorous animals, carnivores, and humans • What life stage is a juvenile digenetic trematode? • cercariae • During the evening and morning hours, what unusual behavior does the ant display? • Ants climb and cling to top of grass at night or early morning • How is D. dendriticumdiagnosed? • Fecal exam for eggs, autopsy of liver, ELISA

  17. References • Janovy, John Jr. and Roberts, Larry S., Foundations of Parasitiology, 8th Edition, 2009 • http://en.citizendium.org/wiki/Dicrocoelium_dendriticum • http://www.cdfound.to.it/html/dicro.htm • www.dpd.cdc.gov/dpdx/html/imagelibrary/Dicrocoeliasis_il.htm • www.suite101.com/content/dicrocoelium-dendriticum-a35177 • http://www.peteducation.com/article.cfm?c=2+2107+2255&aid=731

More Related