II. Epidemiology
- Endemic worldwide in sheep raising areas
- Mediterranean
- Prior Soviet Union block nations
- Australia
- South America
- Africa
- U.S. sources
- Immigrants to North America
- Western U.S. sheep farmers
- Southwestern Native Americans
- Native Inuits in Alaska and Canada (Caribou, wolves)
- Some cases along Mississippi
III. Etiology
- Echinococcus granulosis
IV. Pathophysiology
- Infection with the tapeworm Echinococcus larvae
- Produces expanding cysts (grow at 1-5 cm per year)
- Sites of involvement
- Transmission
- Definitive Host: Dogs and other carnivores
- Intermediate host: Human, Sheep, Cattle
- Infections in Human by ingestion of ova
V. Symptoms
- Asymptomatic in 60% of cases (for 10-20 years)
- Cough
- Abdominal mass
- Hemoptysis
- Chest Pain
VI. Complications
-
Cyst rupture
- Anaphylactic reaction
- Pyopneumothorax
- Mediastinal erosion
VII. Labs
-
Complete Blood Count
- Eosinophilia may be present
- Skin test
- Casoni's Antigen
- Echinococcus serologic titer
- Test Sensitivity: 50% of lung infections
- EITB has highest sensitivity and Specificity
- Fine needle aspiration of cyst
- Tapeworm parts and Eosinophilic granules
VIII. Radiology
- Abdominal Ultrasound or CT: Liver or Kidney Cysts
- Chest XRay: Lung cysts
IX. Management
- Surgical excision of cysts
- Anti-Helminth agents (used concurrently with surgery)
- Albendazole (Albenza)
- Mebendazole (Vermox)
- Not available as of 2012
X. Prevention: Education program in endemic areas
- Carefully wash fruits and vegetables before ingestion
- Avoid water potentially contaminated by dog feces
- Hand Washing after soil exposure
- Treat dogs frequently with worming formulations
- Avoid feeding dogs the entrails of livestock
XI. Prognosis
- Mortality as high as 4-5% in untreated patients