Hydatid Cyst Dr. Nora L. El-Tantawy Ass. Prof. of Parasitology Faculty of Medicine, Mansoura university, Egypt
Echinococcus granulosus Geographical Distribution: cosmopolitan especially in sheep raising countries.
Echinococcus granulosus causes Hydatid disease Definitive host: Dogs and canines Habitat: small intestine of dogs Infective Stage: egg 5 Similar to Taenia egg pass in dog s stool Adult 5 mm 3 1 4 Ingested eggs develop inside these hosts forming Hydatid cyst (1-5) are called Intermediate hosts 2
Development of Hydatid Cyst inside human body Hydatid cysts (from1-10 cm in size) 1% Egg shell dissolves in stomach Blood vessel Lymph vessel 22% 66% 3% Egg Onchosphere Lumen of small intestine 2%
Fibrous layer Laminated layer Germinal layer Morphology of Hydatid Cyst Diagnostic Stage Hydatid sand Hydatid fluid Exogenous daughter cyst Daughter cyst Individual scolices Brood capsules
Pathogenesis and Clinical Picture According to the site of cyst: In the liver: hepatic cyst (about 66%) 1- No symptoms 2- Obstructive jaundice 3- Rupture: Germinal Secondary new cysts Hydatid sand or bites of germinal layer are seeded in the peritoneal cavity. Opens into bile ducts Intermittent jaundice, fever & eosinophilia layer bites Allergic manifestations Anaphylactic shock occurs with sudden rupture of cyst Hydatid sand
Pathogenesis and Clinical Picture In the lung: Pulmonary cyst (about 22%) Cyst present within lung tissue cause: Transient thoracic pain Shortness of breath. Haemoptysis Blood comes out with cough Cyst transforms into chronic pulmonary abscess: Sudden attack of cough with sputum containing frothy blood, mucus and hydatid material.
Pathogenesis and Clinical Picture In the brain: Brain cyst (about 1%) Increased intracranial tension Headache up to epilepsy In the kidney: Renal cyst (about 3%) Intermittent pain & haematuria Hydatid sand may be present in urine. Seen under microscope haematuria
Pathogenesis and Clinical Picture In the bones: Osseous cyst (about 2%) Normally hydatid cyst wall is 3 layered Osseous cyst wall is one layered Fibrous layer Laminated layer Germinal layer Growth of osseous cyst may cause: Bone Erosion Trabeculae Destruction Spontaneous Fracture
Diagnosis of Hydatid Cyst 1- X-ray imaging Round solitary cyst Multiple sharply contoured cysts
Diagnosis of Hydatid Cyst 2- Computerized tomography 3- Ultrasonography Internal daughter cysts Hydatid cyst in liver showing Cart-wheel appearance Cart-wheel
4- Aspiration cytology Diagnosis of Hydatid Cyst Trichrome-stained aspirate 5- Finding hydatid material After surgical removal
6- Intradermal test of Casoni 7- Serological tests Laboratory Diagnosis May give false positive results in 18% May give allergic reactions +ve -By IHA to detect anti-hydatid antibodies in patient s serum -By ELISA to detect hydatid antigen Ab linked to MAb Patient s serum enzyme substrate Hydatid Ag wash wash wash detected -ve 8- Molecular diagnosis Detection of parasite DNA in patient s serum Patient serum Latex particle Sensitized sheep RBCs
Treatment 1- Surgical removal 2- PAIR Technique Percutaneous Aspiration Injection Reaspiration Done under sonographic or CT guidance. Aspiration needle 3- Medical treatment Albendazole Praziquantel
E. granulosus E.multilocularis In Small intestine of dogs World wide In Small intestine of foxes, wolves Eskimos Mode of infection Ingestion of egg similar to Taenia egg Forms Hydatid cyst Favorite site in man is the LIVER (66%) Mode of infection Ingestion of egg similar to Taenia egg Forms Alveolar Hydatid cyst Favorite site in man is the LIVER (90%)
Humans To Be Infected with Alveolar hydatid cyst Foxes & Wolves trapping Fox & wolves skinning
Hydatid cyst Alveolar cyst Unilocular cyst Fibrous, laminated & germinal layers Spongy gelatinous Multilocular cyst Germinal layer Septa Many microscopic scolices (100-1000) Irregular cavities No scolices (Sterile)