Echinococcus ( granulosus and multilocularis )

A B D I RA H M A N G U L A I D

ECHINOCOCCUS (GRANULOSUS AND MULTILOCULARIS)

INTRODUCTION

Echinococcosis:

Echinococcosis commomly known as Hydatid Disease or Hydatidosis, is caused by a parasitic cestodes (tapeworms) of the genus Echinococcus. 

Four species of Echinococcus cause infection in humans are:

E. granulosus causes cystic echinococcosis

E. multilocularis causes alveolar echinococcosis

E. vogeli causes polycystic echinococcosis

E. oligarthrus is an extremely rare cause of human echinococcosis.

THE GEOGRAPHIC DISTRIBUTION

Echinococcus granulosus is widely distributed across Canada and more frequent in rural, grazing areas.

Echinococcus multilocularis occurs in the northern hemisphere, including central Europe and the northern parts of Europe, Asia, and North America. 

E. vogeli and E. oligarthrus occur in Central and South America.

Size Definitive Intermediate

E. granulosus Usually 3 to 6 mm long and consist of a scolex with suckers and hooks, as well as at least three proglottid segments.

Adult worm: (adult worm): wolves, coyotes, domestic dogs

Larval worm: Sheep, Goat, Camel, cattle, Goat, and Horse .

E. Multilocularis 1.2-3.7 mm long with two to six proglottic segments.

Adult worm: Arctic and red foxes, coyotes, sometimes domestic dogs and cats.

Larval worm: rodents (voles, mice, muskrats).Humans

E.GRANULOSUS HOST& E.MULTILOCULARIS HOST

TRANSMISSION AND LIFE CYCLE OF ECHINOCOCCUS

The Hydatid Tapeworm Life Cycle Diagram1. Adult worm present in intestine of definitive host2. Eggs passed in feces, ingested by humans or

intermediate host3. Onchosphere penetrates intestinal wall, carried via

blood vessels to lodge in organs4. hydatid cysts develop in liver, lungs, brain, heart5. After ingestion, the protoscolices attach to the

intestine.6. Ingested protoscolices attach to small intestine and

develops into adult worm and the cycle starts all over again.

LIFECYCLE:

ECHINOCOCCUS EGG IN FECES

SYMPTOMS• E. granulosus

• Can remain silent for years• It is the enlarging cysts that cause symptoms in organs

• Hepatic involvement (75%) (abdominal pain, mass in the hepatic area, biliary duct obstruction)

• Pulmonary involvement (chest pain, Cough, hemoptysis)• Brain, bone, and heart (10-20%)

• Rupture of cyst (fever, hives, pus, anaphylactic shock, and the cyst spreads throughout body cavity)

• E. multilocularis• Affects the liver as a slow growing destructive tumor• Abdominal pain, biliary obstruction, and sometimes metastatic

lesions in lungs and brain are common symptoms

A SECTION OF HUMAN LUNG SHOWS MULTIPLE PROTOSCOLECES LIBERATED FROM A RUPTURED HYDATID CYST

E. MULTILOCULARISSIGNS AND SYMPTOMS OF ALVEOLAR HYDATID

DISEASE

No early symptoms Cysts in multiple body organs Symptoms of liver infestation: upper abdominal

pain , weakness , weight loss , chest pain , cough, coughing blood , jaundice

Symptoms of brain infestation: Blindness Epilepsy

Symptoms of ruptured cysts: Allergic rash Fever

DIAGNOSIS

• Imaging (CT, MRI, and ultrasound)

• Serologic testing (enzyme immunoassay, immunofluorescent assay)

• Examination of cyst fluid

Protoscoleces in a hydatid cyst removed from lung tissue

TREATMENT

Surgical removal via laparoscopy, can be curative for the treatment of echinococcosis

Medication is sometimes effective to keep the cyst from growing back

Praziquantel for definitive host (dog) Albendazole, mebendazole

intermediate host (sheep, other host)

REMOVAL BY SURGERY

CONTROL METHOD

• interrupt lifecycle by an possible means. • Destroy stray dogs

• General education program

• Sheep herders should not live closely with their dogs

- Center of Disease Control. http://www.dpd.cdc.gov/dpdx/html/Echinococcosis.htm

- journals.cambridge.org/production/action/cjoGetFulltext?fulltextd... by JD SMYTH - 1964 - Cited by 64 - Related articles

- www.sciencedirect.com/science/article/pii/0166685185900167 by DP McManus - 1985 - Cited by 42 - Related articles

- www.springerlink.com/index/MD4LQW968V6TUBPE.pdf by CP Nunes - 2004 - Cited by 12 - Related articles 

http://www.fao.org/docrep/t1300t/t1300T0m.htm by A. Permin and J.W. Hansen

SOURCES