Echinococcus multilocularis: Difference between revisions

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Echinococcus multilocularis
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* Intermediate hosts (metacestode) are rodents, possibly pigs, and and incidentally humans
 
* Intermediate hosts (metacestode) are rodents, possibly pigs, and and incidentally humans
 
* Intermediate host is eaten by the definitive host, completing the life cycle
 
* Intermediate host is eaten by the definitive host, completing the life cycle
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=== Epidemiology ===
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* Estimated 18,000 cases annually
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* Worldwide in the northern hemisphere
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** Most cases in China (90%), followed by Japan and Russia
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** Rare in North America
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* Within Canada:
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** Alberta has highest number of cases, with 19 cases from 2013 to 2021
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** 0 to 3 case reports in other provinces
   
 
==Clinical Manifestations==
 
==Clinical Manifestations==
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* Combination of radiologic and serologic investigations
 
* Combination of radiologic and serologic investigations
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*A single negative serologic test does not rule out infection
 
* May be confirmed by biopsy
 
* May be confirmed by biopsy
   

Revision as of 16:45, 23 November 2021


Background

Microbiology

  • Cestode in the Echinococcus family
  • Disease is caused by the larval form

Life Cycle

  • Definitive hosts are canid carnivorous animals
  • Eggs contaminate the environment, including produce
    • They are infective after a few days, and are viable for up to 16 months at 4ºC
  • Intermediate hosts (metacestode) are rodents, possibly pigs, and and incidentally humans
  • Intermediate host is eaten by the definitive host, completing the life cycle

Epidemiology

  • Estimated 18,000 cases annually
  • Worldwide in the northern hemisphere
    • Most cases in China (90%), followed by Japan and Russia
    • Rare in North America
  • Within Canada:
    • Alberta has highest number of cases, with 19 cases from 2013 to 2021
    • 0 to 3 case reports in other provinces

Clinical Manifestations

  • Causes alveolar echinococcosis
  • Incubation period 5 to 15 years
  • Vague abdominal pain may precede diagnosis by years
  • Presents as a metastatic malignancy of unknown primary, mot commonly with malaise, weight loss, and right upper quadrant discomfort
  • Can cause cholestatic jaundrice, cholangitis, portal hypertension, and Budd-Chiari syndrome

Diagnosis

  • Combination of radiologic and serologic investigations
  • A single negative serologic test does not rule out infection
  • May be confirmed by biopsy

Management

  • Main treatment is surgical resection followed by at least 2 years of antihelminthic therapy (e.g. albendazole)
  • Poor prognosis, with 90% 10-year mortality if untreated