Echinococcus multilocularis: Difference between revisions
From IDWiki
Echinococcus multilocularis
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(ββ) |
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** Rare in North America |
** Rare in North America |
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* Within Canada: |
* Within Canada: |
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+ | ** Associated with arctic foxes and wolves |
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** Alberta has highest number of cases, with 19 cases from 2013 to 2021 |
** 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 |
** 0 to 3 case reports in other provinces |
Revision as of 12:16, 4 May 2022
Background
Microbiology
- Cestode in the Echinococcus family
- Disease is caused by the larval form
Life Cycle
- Definitive hosts are canid carnivorous animals, including urban coyotes
- Eggs contaminate the environment, including produce
- They are infective after a few days, and are viable for up to 16 months at 4ΒΊC
- 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:
- Associated with arctic foxes and wolves
- 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
- May also mimic hepatocellular carcinoma, cirrhosis, and tuberculosis
- Causes continuously-growing tumour-like polycystic mass, made up of multiple vesicles that are lined by laminated germinal layer
- 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
Case Definition (Alberta)
- Typical organ lesion detected by imaging with US or CT
- AND histopathology compatible with alveolar echinococcosis
- AND
- Detection of E. multilocularis by serology
- OR detection of E. multilocularis by molecular diagnostic methods
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